Combustion And Flame Questions

We provide combustion and flame practice exercises, instructions, and a learning material that allows learners to study outside of the classroom. We focus on combustion and flame skills mastery so, below you will get all questions that are also asking in the competition exam beside that classroom.

Combustion And Flame Questions

List of combustion and flame Questions

Question NoQuestionsClass
1Which of the following fuel is a mixture of butane and propane?
A . LPG
в. смG
c. Petroleum
D. Kerosene
8
21.
To extinguish petrol fire we can use water.
8
3During an explosion a large amount of ………….. is given out.
T
.
8
4Fossil fuels are found in the earth’s
crust.
A . True
B. False
8
520. Column-1
Column-II
A. Produce less pollutants (p) IPG
on burning
B, Ethyl marcaptan is (9) Wood charcoal
added to check its
leakage
C Used as a fuel in (r) CNG
1
automobiles
D. Fuel obtained by (8) Sugar charcoal
burning wood indoorlyd som vi
o limited supply of air
8
6The product, other than carbon dioxide,
formed when a candle burns in air is:
A. ( C O )
в. ( S O_{2} )
c. water vapor
D. ( N_{2} )
8
7Hottest part of the flame?
(a) blue zone (b) dark zone
(c) luminous zone (d) non-luminous zone
lity that a good fival chand nascas
8
87.
CO, is given off by chemnicals like
(a) NaHCO,
(6) Caso
(c) Na S04
(d) H.SO
8
99.
It is difficult to burn a heap of green leaves but dry leaves
catch fire easily. Explain.
8
1030. Choose the incorrect statement from the following
Forest fires are usually due to :
(a) carelessness of humans
(b) cutting of trees
(c) heat of sun
(d) lightning strike
8
112.
Which of the following has highest calorific value?
(a) Petrol
(b) Coke
(c) Natural gas (d) Kerosene
Combustion is a
reaction
8
12How many moles of methane are
required to produced 22 g ( C O_{2}(g) ) after
combustion?
8
1312. What are the fine particles released on burning carbon-
containing fuels called ?
1. . …11 fanm of CNG and PG?
8
14Which of the following substances does not burn with a flame?
A . LPG
B. Camphor
c. Dry grass
D. Charcoal
8
15What is geothermal energy?
A. Ocean thermal energy
B. Interior heat of the earth.
C. Energy obtained from the heat of hot dry rocks
D. None of these
8
165.
Which of the following diagram shows a non-luminous
flame?
– Pale blue
– Dark blue
+ Dark blue
Pale blue
Yellow
-Dark Blue
– Yellow
– Dark blue
of a liquid in cylinder at
8
1747. “Fire-fighting clothes are made
from
(1) Mica (2) Asbestos
(3) Talc (4) Steatite
8
18Fuels are present in which of the following forms?
A. Solids
B. Liquids
c. Gases
D. All of these
8
191.
Why does a loud noise produced when a fire cracker is
burst?
8
20What is calorific value?
A. Amount of heat energy produced on complete combustion of 1 Kg of fuel.
B. Amount of heat energy produced on complete combustion of ( 100 mathrm{Kg} ) of fuel.
C. Amount of heat energy produced on complete combustion of 1 g of fuel.
D. Amount of heat energy lost on complete combustion of ( 1 mathrm{Kg} ) of fuel.
8
216.
What is the colour of LPG flame ?
8
227.
Cracker on ignition produces sound. Why?
8
23Which of the following statements gives
the correct distinction between the
burning of carbon compounds and
respiration?
A. The burning of carbon compounds is a slow process while respiration is spontaneous.
B. Burning of carbon compounds releases energy in form of ATP while respiration releases in form of light.
C. Burning of carbon compounds is a fast process while respiration is slow.
D. All the above statements are correct
8
24A substance which burn in air is
(combustible/ non-
combustible) substance such as
(hydrogen/ ammonia/ chlorine).
A. Non-combustible, chlorine
B. Combustible, hydrogen
c. Combustible, ammonia
D. combustible, chlorine
8
25Fuel efficiency is measured as
This question has multiple correct options
A. Its calorific value
B. Amount of heat produced by fuel per unit mass or volume
( mathbf{c} cdot k J / K g )
D. None of these
8
261Uvu. LUUI UUS HIUL Vupou 10 UI COMUUSLII.
6.
Assertion : Diesel and petrol can not be used as household
fuels for cooking
Reason: They are highly non-flammable substances.
1. 11
8
27u
walli allu lal UUM
16. Observe the following figure carefully and answer the
following question.
Hot outermost
zone of complete
→ combustion
Innermost zone
of unburnt wax
and gaseous
form
Middle zone of
incomplete
combustion
JU
The Candle
Which zone of candle flame in above figure is the hottest
zone?
(a) Innermost zone
(b) Middle zone
(c) Outermost zone
(d) All flames are equally hot
ant definition of ignition
8
28The process of burning a substance in the presence of air with the evolution of heat is called as
A. distillation
B. carbonisation
c. combustion
D. refining
8
2931. Shyam was cooking potato curry on a chulha. To his surprise
he observed that the copper vessel was getting blackened
from outside. It may be due to :
(a) is readily available.
(b) producers a large amount of heat.
(c) leaves behind many undersirable substances.
(d) burns easily to air at a moderate rate.
8
30The gas which contributes maximum to
the heating value of natural gas is:
A. ( C O )
в. ( C O_{2} )
( mathrm{c} cdot mathrm{H}_{2} )
D. ( C H_{4} )
8
315.
How does water extinguish fire ?
8
322.
Which is/are not fuel(s) ?
(a) Wood
(b) Carbon monoxide
(©) Nitrogen
(d) Oxygen
8
33td UUU UUU
Which fuels are used for running automobiles?
(a) Wood
(b) Coal
(c) Diesel
(d) Charcoal
II
.
1
11
.
8
34Fuels burn to produce heat, light and:
A. ( C O_{2}+ ) water vapour
B. ( C O+O_{2} )
c. ( C O_{2}+H_{2} )
D. ( C O+H_{2} )
8
3511.
Combustion of white phosphorus in air is an example of
……… combustion.
8
36U
14. Which of the following is example of spontaneous
combustion?
(a) Burning of matchstick
(b) Combustion of fuel by motor vehicles.
(c) Lightning of kerosene lamp.
(d) Combustion of coal dust in coal mines.
8
37Water cannot be used as fire
extinguisher to put out
A. burning wood
B. burning oil
c. burning cloth
D. burning charcoal
8
38Which selection is an example of a combustion reaction?
A ( cdot 2 K+F_{2} rightarrow 2 K F )
в. ( 2 A l+6 H C l rightarrow 2 A l C l_{3}+3 H_{2} )
c. ( C_{3} H_{8}+5 O_{2} rightarrow 3 C O_{2}+4 H_{2} O )
D. ( N a C l+A g N O_{3} rightarrow A g C l+N a N O_{3} )
8
395.
Give reasons:
(a) Water is not used to control fires involving electrical
equipment.
(b) LPG is a better domestic fuel than wood.
(c) Paper by itself catches fire easily whereas a piece of
paper wrapped around an aluminium pipe does not.
11
8
408.
Vapourised wax gets oxidised in
(a) blue zone
(b) dark zone
(c) luminous zone (d) non-luminous zone
8
41Colour of outer zone of a candle flame is blue while middl
zone is yellow in colour.
8
42An organic compound contains ( 69 % )
carbon and 4.85 hydrogen, the remainder being oxygen. The masses of carbon dioxide and water produced when 0.20 g of this substance is subjected to complete combustion?
A. ( 0.506 g ) and 0.0864 g
в. ( 0.678 mathrm{g} ) and ( 0.0234 mathrm{g} )
c. ( 0.786 g ) and 0.0128 g
D. None
8
438.
Explain how CO, is able to control fires.
8
44What type of materials gives flame?
A. All materials
B. Materials which vaporise on heating
C. Materials which melt on heating
D. None of the above
8
45Column-II
(p) Respiratory irritants
(9) Rapid combustion
Column-I
A. Oxides of sulphur
and nitrogen
B. Burning of gasoline
in automobiles
C Fuel burnt in
vapour phase
D. Use of LPG as
domestic fuel
(r) Acid rain
(s) Flame
8
46Which of the following diagrams shows a non-luminous flame?
A. I only
B. II only
c. I and II
D. II and IV
8
471.
Column-I
Column-II
Oxygen
(q) Ignition temperature
Materials which
burn readily
B. Heat produced by
burning unit mass
of fuel
C. Point of catching fire
D. Supporter of
combustion
(r) Calorific value
() Combustible
8
48and
Ogun son u
TUU III
WU W
IOLUCIU.
4.
Unburnt carbon particles causes
(a) Stomach infections (b) Respiratory problems
(c) Brain infections (d) Throat problems
Cuba
ammincianced dieto
o ncentration of
8
49Call valu UI LIUI.
2. Can the process of rusting be called combustion? Discuss.
2
Abida and Ramesh were doing an eyneriment in which water
8
50Write down the examples of each types of fuel in the given
table.
S.No. Solid fuel Liquid fuel | Gaseous fuel
TIS
1

1M
A01.1/1. and
8
516.
Pape Wlappeu dlounu au au
Make a labelled diagram of a candle flame.
1 . 1 1
1. c. ln
ef.
fi
8
522
– 400 P
SI HITO POLOSSFull CliÚI te
26.
Place a piece of burning charcoal an iron plate and cover it
with a plastic jar. The charcoal stops burning because
(a) its ignition temperature is lowered
(b) supply of oxygen is out off
(c) it becomes cold after some time
(d) None of the above
11
8
53coal anu UUDUL W10H
heat and light are the
11.
Carbon dioxide, water vapours, heat and light
products of combustion.
modo
id fire
:
8
54Carbon dioxide is used in fire
extinguisher.
A. True
B. False
8
5523. How many types of charcoal are known?8
56ue
11.
Which of the following is/are advantage(s) of gaseous
fuels?
(a) They have high heat content
(b) They are clean in usein
(c) They can be lighted at moment’s notice
(d) They can be transported through network of pipelines
Which of the following in Hind i
8
57Fuel efficiency depends on:
A. properties of fuel
B. properties of engine
C. Both A and B
D. None of the above
8
58Why water cannot control fire caused by oil or petrol?
A. Water reacts with oil
B. Water is denser than oil
c. water is less denser than oil
D. Water mixes with oil
8
59The flame of candle has three zones. The
outer zone is yellow, the middle zone is blue and the inner zone is black. Which
is correct regarding this?
A. The outer zone is least hot
B. The middle zone is hottest
c. The inner zone is least hot
D. All the zones have same temperature
8
60Explain the different zones of a candle flame.8
61.
Digestion of food is in an example of
(a) incomplete combustion
(b) complete combustion
(c) slow combustion
(d) rapid combustion
8
62Carbon dioxide is neither combustible
nor a supporter of combustion.
A. True
B. False
8
634.
Write the colours of the flame produced by
(a) Kerosene lamp
(b) Candle
(c) Bunsen burner
8
64Which of the following do not produce flame on burning?
A . Petrol
B. coal
c. L.P.
D. Kerosene
8
653.
Explain how the use of CNG in automobiles has reduced
pollution in our cities.
5.
8
664.
A flame always points upwards. Why do you think this is
so?
(Hint: Gases produced in a flame are hot, and hence lighter)
1
, a
o
bon Grou ka
8
67A wet cotton handkerchief soaked in
alcohol will not each fire even it is set
fire to? Why?
8
6818. Which of the following is correct definition of calorific value
of fuel?
(a) It is the amount of heat required for burning one unit
of fuel in presence of oxygen.
(b) It is the amount of heat energy given out on burning
one unit of fuel.
(c) It is the amount of heat energy given out on burning
one unit of solid fuel.
(d) It is the amount of heat energy given out on burning
one unit of gaseous fuel.
10 Thich of the following is best explanation of statement
8
69The hottest region of Bunsen flame shown in the figure below is:
A. region 2
B. region 3
c. region 4
D. region
8
7010. Oxides of sulphur and nitrogen are produced by burning of
coal and diesel which cause acid rain.
8
71Fill in the blanks:
(a) Burning of wood and coal causes of air.
(b) A liquid fuel, used in homes is
(c) Fuel must be heated to its
before it starts burning.
(d) Fire produced by oil cannot be controlled by
8
72Which of the following is a noncombustible substance?
A. coke
B. Diamond
c. coal
D. woodd
8
73(
U bunSell vure
Give any three examples of solid, liquid and gaseous fuels.
5.
19
8
744.
In luminous zone of candle a incomplete combustion of wax
In luminous
vapours takes place with liberation of maximum heat energy.
8
75Name any two types of fire extinguishers commonly used
How does water extinguish fire?
8
768.
Incomplete combustion of a fuel gives carbon dioxide.
8
77Match the column I with Column II and
select the correct option from the codes
given below.
(a) begin{tabular}{l|l|l}
column I & & Column II \
& \
Hottest zone of candle flame & (i) & Zone of unburunt wax vapours. \
Yellow zone of candle flame & (ii) & Nonluminous zone \
Black innermost zone of the candle flame & (iii) & Incomplete combustion zone/ \
hline
end{tabular}
(b)
( (c) )
( A )
(a) – (i), (b) – (ii), (c) – (iii)
B. (a) – (ii), (b) – (i), (c) – (iii)
c. (a) – (i), (b) – (iii), (c) – (ii)
D. (a) – (ii), (b) – (iii), (c) – (i)
8
7810. Which zone of a flame does a goldsmith use for melting
gold and silver and why?
8
79The safest and the most common
alternative of sugar is
A. glucose
B. aspartame
c. saccharine
D. cyclodextrin
8
802.
What is the cause of smoky flame ?
ab
2
8
81What are the harmful effects of increasing consumption of
fuels?
TYT –
1
10
8
8222.
How many of the following are liquid fuels ?
Paraffin wax, kerosene, diesel, CNG, LPG, charcoal and
acetylene.
8
83The temperature of oxy-acetylene flame
is
( mathbf{A} cdot 200^{circ} mathrm{C} )
в. ( 1600^{circ} mathrm{C} )
( c cdot 2000^{circ} C )
( mathbf{D} cdot>2500^{circ} mathrm{C} )
8
84How will you distinguish between fire
extinguishing action of water and ( C O_{2} )
( ? )
A. Water helps to extinguish a fire in two ways: (1) It brings the temperature of the combustible material below its ignition temperature.
(2) The water vapour formed due to the heat of fire cuts the supply of oxygen.
B. Carbon dioxide is highly volatile. So, it immediately vaporises to cut off the supply of air. In the absence of supporter of combustion, fire is extinguished.
( c . ) Both ( A ) and ( B )
D. None of the above
8
85Fuel gases containing hydrocarbons (ie.g. coke oven gas) are not preheated before burning, mainly because
A. the hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot
B. it reduces its calorific value tremendously
c. it reduces its flame temperature tremendously
D. there are chances of explosion during preheating
8
86LULUI
20.
15. Which of these materials would you use a water fire
extinguisher on?
(a) paper
(b) wood
(c) plastic
(d) all of these
8
87A circular blackish ring on the glass plate kept over the candle flame
indicates
A. Complete combustion
B. Dark zone of the flame
c. Non-luminous zone
D. Luminous zone
8
88()
IT SILUL 15 MICUITI UU NAJUA
WRv.
15. Assertion : The main constituent of LPG is butane.
Reason: A small quantity of mercaptan is added to cooking
gas cylinders supplied for domestic use.
8
895.
Wood is a better fuel than LPG.
8
90You are provided with three watch glasses containing milk,
petrol and mustard oil, respectively. Suppose you bring a
burning candle near these materials one by one, which
material(s) will catch fire instantly and why?
8
91A good fuel has these qualities:
This question has multiple correct options
A. Should have high calorific value
B. Should be costly
c. should cause pollution
D. Should be easy to transport
8
92The ignition temperature of an ideal fuel should
A. Lowest
B. Highest
c. Neither too high nor too low
D. None of the above
8
93Air contains ( 21 % ) of oxygen by volume.
Calculate the volume of such air
required for the complete combustion
of ( 700 mathrm{cm}^{3} ) of ethylene ( left(C_{2} H_{4}right) ) at ( 15^{circ} mathrm{C} )
and 756 mm pressure.
8
94In photosynthesis in plants, ( boldsymbol{H}_{2} boldsymbol{O} ) and
( C O_{2} ) react in presence of light and chlorophyll to give carbohydrate and oxygen.When the carbohydrate is burnt in air, the gases produced are:
A. ( C O_{2}+H_{2} )
в. ( C O_{2}+C O )
c. ( C O_{2}+H_{2} O )
D. ( C O_{2}+O_{2} )
8
95Two glass jars ( A ) and ( B ) are filled with carbon dioxide and oxygen gases,
respectively. In each jar a lighted candle is placed simultaneously. In which jar will the candle remain lighted for a longer time and why?
8
96Which of the following is an ideal fuel?
A. coal
B. LPG
c. Petrol
D. None of these
8
97Substance which vaporize during burning gives
A. sound
B. flame
c. combustion
D. none of these
8
981.
The substance A may be
(a) Honey
(c) Hydrogen
(b) Wax
(d) Plasticide
8
99Which of the following is an example of rapid combustion?
A. Burning of wood
B. Burning of LPG
c. Burning of coal
D. Burning of a candle
8
1001.
Assertion : Innermost zone of the eis cooler than the
outer zones and is dark.
Reason: The middle zone is largest zon flame and this
zone gives soot and smoke.
8
101Carbon monoxide is neither combustible nor a supporter of
combustion.
8
102Which of the following is eco friendly combustible substance?
A . Diesel
B. Petrol
c. c. N.G
D. cow dung
8
103Estimate the maximum possible
temperature of a Bunsen burnur flame.
8
10413.
The substances which have very ………….. ignition
temperature and can easily catch fire with a flame are called
………… substances.
8
1051.
What is a flame?
8
106During an explosion, a large amount of is given out8
107Autoignition temperature is the highest temperature at which substance can burn.
A. True
B. False
8
108Combustion is an
A. exothermic reaction
B. endothermic reaction
C. displacement reaction
D. reduction reaction
8
109Explain why kerosene doesn’t catches fire easily whereas petrol does?8
110Fossils are present in metamorphic rocks. State true or false.
A. True
B. False
8
111How many among the following are solid fuel ?
Petrol, LPG Coal, Wood, Cow dung cake, Charcoal , CNG,
Biogas.
8
112Which of the following chemicals starts the combustion process in the matchstick?
A. antimony sulphide
B. potassium chlorate
c. phosphorous
D. starch and wool
8
1134
Incomplete combustion of fuel produces
(a) CO2
(b) CO
(c) HO
(d) H,
Combustion is the
8
1146.
It is difficult to burn dry leaves but green leaves catch f
easily.
8
1155.
The calorific values of petrol and CNG are 45000 kJ/kg and
50,000 kJ/kg, respectively. If you have vehicle which can
run on petrol as well as CNG, which fuel will you prefer and
why ?
8
116uneuvo SX u XXVI vet Jul Kldson 15 COTECT.
17. Assertion : Water fire extinguishers can be used for solids
only, such as wood, paper, plastics and fabrics
Reason: water is a bad conductor of electricity
ng
pe
8
117On burning fuel produces amount of heat.
A. large
B. less
c. very less
D. no heat
8
118Give reasons why respiration is called slow combustion?8
1196.
Fire extinguishers extinguish the fire by
(a) cutting off the supply of air
(b) bringing down the temperature of fuel
(c) supplying air to the fuel
(d) bringing down the temperature of fire
8
120Why the innermost zone of candle flame
is the least hot?
A. Unburnt wax vapour
B. No supply of oxygen
c. Presence of wick
D. All the above
8
12121. LPG burns with a
(a) non-luminous flame
(b) luminous flame
(c) yellow flame
(d) both (a) and (b)
8
122During burning of candle, different zones of combustion in the flame are listed below:
a) Outermost zone
b) Innermost zone
c) Middle zone
The correct order of temperature of zones is :
( mathbf{A} cdot A>B>C )
в. ( C>B>A )
c. ( B>C>A )
D. ( A>C>B )
8
123&
………….. is used to control fires involving electrical
equipments.
.. is used to control fires involving electrical
8
124Combustion is a:
A. physical process
B. chemical process
C. biological process
D. mechanical process
8
1251.
Which of the following substances is used in place of H2SO4
in foam type of fire extinguisers ?
(a) Saponin
(b) Aluminium sulphate
(c) Sodium carbonate (d) Alcohol
8
12615. Molten wax on heating releases
(a) water and carbon dioxide
(b) carbon and hydrogen
(c) carbon dioxide and hydrogen
ba (d) water and carbon
11.
8
127DI
As.
the
10. Which of the following is/are advantage(s) of liquid fuels?
(a) Require less furnace space for combustion
(b) Clean in use
(c) Can be stored indefinitely
cibo
(d) Leaves less ash content
th
(a
8
12820.
A.
B.
C.
D.
(a)
(b)
(c)
(d)
Column-I
Column-II
Petrol
(p) Water
electrical wires (q) Foam
textile
(r) Dry powder
flammable gases (s) CO2 gas
A-q, r, s; B-r,s; C-p, q,r;D-r
A-s; B-r,s; C-q,r;D-r
A-r,s;B-s; C-p,r;D-r
A-q,r; B-r; C-p,q,r; D-s
8
129Give any two advantages of hydrogen as
a fuel.
8
130How can you make a flame thrower with
orange?
8
131A burning substance will be if the temperature falls below its ignition temperature.
A. extinguished
B. burning brightly
c. burning dimly
D. burning with smoke
8
132Combustion is a ……… reaction accompanied by heat and
light-
(a) reduction
(b) redox
(c) substitution (d) oxidation
Outormast zone of flame is called
8
13310. Respiration is a ………….. combustion.8
134What are acid anhydrides?8
135Wrap a thin paper strip tightly around an iron rod. Try to burn the paper with candle while rotating the iron rod continuously. Does it burn?8
136Make a labelled diagram of a candle flame.8
137Fire is extinguished by:
A. removing all combustible substance
B. cutting off supply of air
C . cooling the burning substance
D. all of these
8
138Abida and Ramesh were doing an experiment in which water
was to be heated in a beaker. Abida kept the beaker near the
wick in the yellow part of the candle flame. Ramesh kept the
beaker in the outermost part of the flame. Whose water will
get heated in a shorter time?
8
139Explain:
A: Combustion is an exothermic
process.
B: Combustion is a spontaneous
process
8
1402.
How many among the following are produces flame
Candle, Magnesium, Camphor, Coal
8
14112. Which of the following is/are disadvantage(s) of gaseous
fuels ?
(a) very large storage tanks are needed
(b) higher possibilities of fire hazards
(c) they are costly
(d) they leaves no ash on burning
8
142The different zones of a candle flame
are marked by the letters, ( A, B ) and
C. Which of the following is correct?
A. ( B ) is the hottest part of the flame
B. ( C ) is moderately hot.
( mathrm{C} ). A is the hottest part of the flame
A is moderately hot whereas ( C ) is the coldest partt
8
143Write characteristics of an ideal fuel.8
14428. The substance that does not burn with flame is
(a) JPG
(b) dry grass
(c) camphor
(d) charcoal
8
145In which zone of a candle flame does
complete combustion take place?
A. Inner
B. Outer
c. Middle
D. All three zones
8
146Ignition temperature of flammable substances is
A . high
B. low
c. very high
D. None
8
147What is the necessary for combustion?
A. Fuel
B. Supply of oxygen
c. source of ignition
D. All of the above
8
148A chemical process in which a substance reacts with oxygen to give off heat is called as:
A. endothermic
B. combustion
c. reduction
D. none of the above
8
149The substances which vapourise during
burning, give flame.
A. True
B. False
8
15019. Assertion: The heat of the flame vaporizes the liquid wax.
Reason: These vaporized molecules are drawn up into the
flame
8
1516.
On burning, solid fuels leave residue and…
8
1522.
Give reasons for the following:
(a) The use of diesel and petrol as fuel in automobiles is
being replaced by CNG.
(b) A matchstick starts burning by rubbing it on the side
of the match box.
8
153Write the equation for the complete combustion of ethane.8
154Which of the following is the most common fire extinguisher?
A. Foam
в. ( C O_{2} )
c. water
D. Dry powder
8
155Middle zone is the hottest zone of a
flame.
A . True
B. False
8
15612. At airport and petrol pump soda acid fire extinguishers are
not used.
ФУүс
:
:
1
1:
8
157What are the various problems caused by combustion of
fuels ?
8
158The zone of no combustion is
A. The middle zone
B. outermost zone
c. The base of the flame
D. Innermost zone
8
159Coke is a fuel.
A. ashless
B. renewable
C. smokeless
D. harmless
8
160Which substance is not used as a fuel?
A. Ethanol
B. Hydrogen
C. Methane
D. oxygen
8
161Which one of the following is noncombustible?
A. Stone piece
B. Paper
c. Straw
D. Matchsticks
8
16211
Select the fuel with highest calorific value ?
(a) LPG
(b) Kerosene oil
(c) Wood
(d) Hydrogen gas
8
163Compare LPG and wood as fuels.8
164Which of the following is an excellent fuel?
A. Solid fuel
B. Liquid fuel
c. Gaseous fuel
D. None of the above
8
165Which lipids are present in essential
oils?
8
166Why Hydrocarbons are considered as
better fuel?
8
167What reactant must be present for a reaction to be classified as
combustion?
A ( cdot C l_{2} )
в. ( C H_{4} )
( c cdot O_{2} )
D. ( C O )
8
168Which of the following statement is NOT
true?
A. Flame can be seen over burning solids and liquids
B. Type of flame depends upon the amount of oxygen available
C. Invisible zone of a flame is the least hot zone
D. Blue-zone indicates complete combustion of fuel
8
169Which of the following can be considered as an ideal fuel?
A. Kerosene
B. Petrol
c. Biogas
D. woodd
8
170The process of burning wood in limited supply of oxygen to obtain charcoal as a resultant product is called:
A. Destructive distillation
B. Simple distillation
c. Fractional distillation
D. Azeotropic distillation
8
171Coke oven gas consists mainly of
A. ( H_{2} ) and ( C H_{4} )
в. ( C O ) and ( C O_{2} )
c. ( H_{2} ) and ( C O )
D. ( C H_{4} ) and ( C O )
8
17225. The head of the safety match contains a mixture of
a) antimony trisulphide and potassium chlorate.
6) potassium chlorate and red phosphorus
(©) antimony trisulphide and white phosphorus
(d) glass powder and potassium chlorate
8
173A form of combustion reaction where
there is a release of high amount of a heat and light energy in a small interval of time is
A. spontaneous combustion
B. rapid combustion
c. fast combustion
D. instant combustion
8
174Fire can be extinguished by spraying:
A. carbon dioxide
B. carbon tetrachloride
c. water
D. all of the above
8
175A lilac-coloured flame is produced on heating.
A. Potassium in a flame
B. Cobalt in a flame
c. Sodium in a flame
D. Methane in oxygen
8
176A solution of compound ( Z ) gives a light blue precipitate with aqueous ammonia. The precipitate
dissolves in an excess of ammonia.
A flame test is done on compound ( Z ) What is the colour of the flame?
A. Blue-green
B. Lilac
c. Red
D. Yellow
8
177In combustion, the substance reacts
with
A. hydrogen
B. oxygen
c. nitrogen
D. carbon dioxide
8
178A white solid ( X ) reacts with dil. ( H C l ) to
give colourless gas which is used in fire extinguishers. The solid ( boldsymbol{X} ) is:
A ( . ) NaCl
в. ( C H_{2} ) СОО ( N a )
( mathbf{c} cdot N a_{2} C O_{3} )
D. ( operatorname{NaH} mathrm{CO}_{3} )
8
179Which is the hottest part in the flame of the candle?
A. Blue
B. Yellow
c. Black
D. Wax part
8
180Match column ‘A’ with column’B’ as
regard to characteristics of a flame and
its zones.
‘A’
1. Hottest part (No
a. Dark inner zone
Blue zone
2. Partial decomposition
b.
3. Unburnt vapours of c. Luminous zone
d. Non-luminous
zone
4. Complete combustion
( A cdot a-1, b-2, c-3, d-4 )
B. ( a-2, b-3, c-4, d-1 )
( c cdot a-3, b-4, c-2, d-1 )
( D cdot a-4, b-1, c-2, d-3 )
8
181es
Why does the flame of candle rise up to good height on
burning?
8
182In which of the following compounds
maximum heat is liberated on
combustion of one mole of the
compound?
A. Hydrogen
B. Methane
c. Ethane
D. Butane
8
183is any material that can be made to react so that it releases
chemical or nuclear energy as heat.
A . Fossil fuel
B. Fuel
( c . ) oil
D. All of the above
8
184Which of the following has the characteristics of a good fuel?
A. coke
B. Butane
c. coal
D. Kerosene
8
185Which of the following releases less amount of pollutants on combustion?
A . Diesel
B. Coal gas
c. c. N.G
D. water gas
8
186Innermost zone is the
A. hottest part
B. moderately hot part
c. least hot part
D. cold part
8
1878.
Name three substances used to extinguish fire.
8
188On placing an inverted tumbler over a burning candle, the flame extinguishes after some time. This is because of the
non-availability of:
A. oxygen
B. water vapour
c. carbon dioxide
D. wax
8
1899.
Ignition temperature of a log of wood is………….. than a
splinter.
8
190Combustion is a process involving:
A. oxidation
B. reduction
c. liberation of heat
D. all of the above
8
191Good fuel is:
A. Readily available
B. Cheap
C. Burn easily in air
D. All of these
8
192Abida and Ramesh were doing an experiment in which water was to be
heated in a beaker. Abida kept the beaker near the wick in the yellow part of the candle flame. Ramesh kept the
beaker in the outermost part of the
flame. Whose water will get heated in a shorter time?
8
19320. Which of the following is best explanation of statement:
Water should never be used to extinguish oil fires.
(a) Water is heavier than oil, on spraying water it sinks
and oil floats, and the fire continues.
(b) Water is lighter than oil, on spraying water it sinks and
oil floats and the fire continues.
(c) Water reacts with oil and form a new flammable
compound.
(d) Oil fire is very intense it convert water in to steam and
evaporate it off.
1 Tabu
8
194( Delta U^{ominus} ) of combustion of methane is
( -X k J m o l^{-1} ) The value of ( Delta H^{ominus} ) is
( A cdot=Delta U^{ominus} )
в. ( >Delta U^{text { }} )
( mathrm{c} cdot<Delta U^{circ} )
D.
8
195Water is used to extir
(a) raises the igni
(b) lowers the
is used to extinguish fire because water
ses the ignition temperature of the burning substance.
towers the ignition temperature of the burning
substance.
cools the burning substance to a temperature below its
ignition temperature. Non
conducts the heat.
D ad
8
196Explain the principle on which a fire extinguisher works.8
197Combustion of fuel is:
A. displacement reaction
B. double displacement reaction
C. oxidation reaction
D. isomerisation reaction
8
1984.
Compare LPG and wood as fuels.
8
199— –
Jov
v и оирро са о сопсихоп
5.
Assertion : Candle burns with a flame whereas coal does
not.
Reason: Coal does not vapourise on combustion.
8
200The substance which undergoes combustion is called
A . fue
B. non-inflammable
c. combustible
D. Both ( A & C )
8
201Burning is accompanied with
(a) evolution of heat (b) evolution of energy
(c) evolution of light (d) evolution of electricity
8
202Assertion : Fire can be extinguished by cutting off the
supply of oxygen.
Reason: Oxygen is a supporter of combustion
8
203#NAME?8
2042.
Which of the following is/are carbon fuel
(a) Wood
(b) Coal
(c) Petroleum
(d) All of these
8
205Which of the follwoing Hydrocarbon is
used as a fuel?
A. ( C O_{2} )
B. ( C_{4} H_{10} )
( mathbf{c} cdot C H_{3} O H )
D. ( C H_{3} ) СООН
8
206опе иппо Вазсам тис.
19. Which of the following is best explanation of statement:
Metabolism of glucose is considered as combustion
(a) It involves reaction of glucose molecule with oxygen
(b) Products obtained are CO2 and H O therefore it is a
combustion reaction occurs at slow and steady rate.
(c) This reaction occur as rapid as combustion reaction.
(d) This reaction release enormous amount of energy
11
8
207(a) Label different zones of candle flame in the following
figure.
(b) Explain the three different zones of candle flame. What
kind of combustion occurs in each?
8
208Ideal fuel has a
calorific value.
A. low
B. highh
c. moderate
D. zero
8
209Choose the correct statement from the
following. A good fuel is one which:
This question has multiple correct options
A. is readily available
B. produces a large amount of heat
c. leaves behind many undesirable substances
D. burns easily in air at a moderate rate
8
21021. Candle flame contain how many flames?
1
1
1
0
8
211The products of a burning candle are:
A. ash and water vapour
B. ( C O_{2} ) and water vapour
c. wax and water vapour
D. only melted wax
8
212The blue zone in an LPG flame indicates:
A. unburnt vapours
B. partial decomposition
c. moderately hot
D. hottest and complete combustion
8
2133.
Assertion : Calorific value of methane is greater than ethane
Reason: Fuels having higher percentage of hydrogen have
higher calorific value.
8
214A chemical process in which a
substance reacts with oxygen to give off heat is called?
A . lgnition
B. Combustion
c. conduction
D. None of the above
8
215Light a Bunsen burner and adjust the
air hole at the base to get different types of flames/presence of smoke. When do you get a yellow, sooty flame? When do you get a blue flame?
8
216OD PO
2.
Carbon dioxide is effective for fire fighting.
8
21712.
Which one is the best fire extinguisher ?
(a) SO
6) CO2
c) NO,
(d) 0₂
The color flumine
n
.com
Anne
8
218While cooking, if the bottom of the vessel is getting blackened on the outside, it means that
A. the food is not cooked completely
B. the fuel is not burning completely
c. the fuel is wet
D. all of the above
8
219(с) тероосоо
24.
In presence of water, ignition temperature of paper
(a) decreases (b) increases
(c) remains constant (d) can decrease or increase
8
2206.
What are the disadvantages of using wood as a fuel ?
8
22101 CUVU
3.
Fuel may be
(a) Solid
(c) Gas
(b) Liquid
(d) All of these
8
222The characteristics of a ideal fuel are:
A. it should release more energy
B. it should be safe
c. it should be easily transportable
D. all of the above
8
223Which of the following is a necessary condition for a combustion reaction to
take place?
A. Flame is required
B. Spark is replied.
c. The temperature of the substance should be increased to ignition temperature.
D. Nothing is required
8
2243.
What is a fire extinguisher ?
8
2253.
The ………….. zone in a candle flame is the zone of no
combustion.
8
226What is used as a fuel injet planes?
A . Liquid Petrol
B. Diesel oil
c. Kerosene
D. Gasolene
8
227Although wood has a very high calorific value, we still
discourage its use as a fuel. Explain.
8
228Colour of the flame is dependent on the
A. supply of oxygen
B. nature of fuel
c. ignition temperature of the fuel
D. All of the above
8
22912. Liquefied Petroleum Gas (LPG) consists of mainly?
(a) Methane Ethane and Hexane
(b) Ethane Hexane and Nonane
(c) Methane Butane and Propane
(d) Ethane Nonane and Methane
8
230is a better domestic fuel than
wood.
A. cNG
B. LPG
c. Petrol
D. All of above
8
231The heat of combustion of benzene at
( 27^{circ} mathrm{C} ) found by bomb calorimeter i.e. for
the reaction ( C_{6} H_{6(l)}+7 frac{1}{2} O_{2(g)} rightarrow )
( mathbf{6} C O_{2(g)}+mathbf{3} H_{2} O_{(l)} ) is 780 K.Cal ( m o l^{-1} )
The heat evolved on burning 39 g of benzene in an open vessel will be
A. 390 K.Cal I
B. 780.9 K.Cal
c. 390.45 K.Cal
D. 780 K.Cal
8
232A wax candle burns with yellow flame.
Give reason.
8
233Types of combustion are:
A. rapid, cracking and dazzling
B. spontaneous, rapid and explosive
C. explosive, dazzling and glowing
D. spontaneous and rapid
8
234Explain how the use of CNG in automobiles has reduced pollution in our cities.8
23514. What is SI unit of calorific vlaue?8
236Which of the following has highest calorific value?
(a) Petrol
(b) Coke
(C) Natural gas (d) Kerosene
Combustion is a
reaction
8
2372.
The substance B may be
(a) Hydrogen
(c) plastics
(b) Liquid
(d) wax
8
238Coal, petroleum natural gas, and
propane are fossil fuels They are called
fossil fuels because
A. they are burnt to release energy and they cause air pollution
B. they were formed from the buried remains of plants and tiny animals that lived hundreds of millions of
years ago
C. they are nonrenewable and will run out
D. they are mixed with fossils to provide energy
8
239What volume of air (containing ( 20 % O_{2} ) by volume) will be required to burn
completely ( 10 mathrm{cm}^{3} ) each of methane and
acetylene
( boldsymbol{C H}_{4}+mathbf{2 O}_{2} longrightarrow boldsymbol{C} boldsymbol{O}_{2}+mathbf{2} boldsymbol{H}_{2} boldsymbol{O} )
( 2 C_{2} H_{2}+5 O_{2} longrightarrow 4 C O_{2}+2 H_{2} O )
8
2407.
TUU 510 VITUIT VI
u Wake It quid
Mark the incorrect statement.
(a) Burning of coal in a sufficient amount of oxygen
produces carbon dioxide.
(b) When coal burns in insufficient amount of oxygen,
carbon monoxide is formed.
(c) Charcoal is a better fuel than kerosene to be used as
fuel for cooking at home.
(d) LPG is considered to be a good fuel for domestic use.
8
2415
OLULU 1 UNUI
10. Why is sand used for fire extinguished to be efficient?
8
242Anu wants to boil water quickly in a test tube. On observing
the different zones of the flame, she is not able to decide
which zone of the flame will be best for boiling water quickly.
Help her in this activity.
8
2439.
Which of the following is/are advantage(s) of solid fuels ?
(a) Their ash content is high
(6) They are easy to transport
(C) Cost of production is low
(d) Easy to store
8
244Why is CNG a cleaner fuel?
A. No particulate emission
B. Releases very less amounts of sulphur and nitrogen oxides
C. No emission of ash
D. All of the above
8
245Compare the usefulness of solid, liquid and gaseous fuels.8
246The flame of the candle has three zones.
The outer zone is blue, the middle zone
is yellow and the inner zone is black. Which is correct regarding this? This question has multiple correct options
A. The outer zone is hottest hot
B. The middle zone is hottest
c. The inner zone is least hot
D. All the zones have same temperature
8
247How many zones are present in candle flame?
A .2
B. 3
( c cdot 4 )
( D )
8
248Which of the following is not a solid
fuel?
A. Paraffin
B. coal
c. Tallow
D. Benzene
8
249A good fuel has these qualities:
This question has multiple correct options
A. should have high calorific value
B. should be costly
C. should cause any pollution
D. should be easy to transport
8
250


4.
The salt used in soda acid type extinguisher is
(a) potassium chlorate
(b) sodium nitrate
(c) sodium bicarbonate
(d) potassium sulphate
8
2516.
Ethyl mercaptan is added to LPG
(a) to give colour to it (b) to give volume to it
(c) to give smell to it (d) to make it liquid
8
25213. What is the full form of CNG and LPG?
W
. CL
falariga ulan2
8
253Which of the following is not a combustible substance?
A. Camphor
B. Glass
c. Straw
D. Alcohol
8
254How carbon dioxide is stored in the
house to extinguish fire?
A. It can store in the bottles
B. It can store in the cylinders under high pressure
c. It can store in canes
D. It can not store in any form
8
2555.
………….. is a gaseous fuel which can be stored in cylinders.
On burning solid fuels leave residue and
8
256Duo PM
5.
Only gases burn with a flame. When you burn wood it
initially burns with a flame. Later it only glows without a
flame. What do you think the answer is?
1
1
:1.
8
257When fuel is added to the exhaust
(burnt) gases in a jet engine combustion takes place. Some facts are mentioned here about this combustion.
Pick the false one?
A. It increases the intake of oxygen from the air
B. It reduces fuel consumption
c. It gives additional thrust
D. It is known as ‘after burning’
8
258Which of the following is combustible?
A. Oxygen
B. Carbon dioxide
c. Hydrogen
D. All of these
8
25917. Which of the following is correct definition of ignition
temperature?
(a) The lowest temperature at which a substance catches
fire spontaneously.
(b) The lowest temperature at which a substance catches
fire.
(c) The lowest temperature at which a substance changes
its physical state.
(d) The lowest temperature required for a chemical reaction
to take place.
8
260How ( C O_{2} ) controls fire?
A. forms a blanket around fire.
B. brings down temperature of the fuel.
C. Both A and B.
D. None of above.
8
2616.
When a fuel is burnt, carbon dioxide (or carbon monoxide)
and water vapour are given out. Can you name one fuel
which burns without giving off water vapour?
8
262Why do goldsmiths use outermost flame to burn gold and silver?8
263Burning of coal and wood causes
A. pollution of air
B. decrease of non-renewable source of energy
C. both (a) and (b)
D. neither (a) or (b).
8
264following materials as
Boojho wants to separate the following
vible and non-combustible. Can you help him
8
265Manu was heating oil to fry potato chips. The cooking oil
all of a sudden caught fire; he poured water to extinguish
the fire. Do you think this action was suitable. If yes, why?
If not, why not? In such a condition what should Manu
have done?
8
266Why electrical equipment on burning do not extinguished fire by water?
A. Water shows exothermic reaction with electrical equipment
B. Water conduct electricity with electrical equipment’s.
C. Water shows endothermic reaction.
D. Water is a combustible substance.
8
267Choose the correct statement about
inflammable substances from the
following statements. They have:
A. low ignition temperature and cannot catch fire easily
B. high ignition temperature and can catch fire easily
c. low ignition temperature and can catch fire easily
D. high ignition temperature and cannot catch fire easily
8
2687.
Why does charcoal not produce flame?
8
26916. Besides a Co, fire extinguisher, which type of fire
extinguisher can you use on electrical fires?
(a) Wet chemical fire extinguisher
(b) Foam fire extinguisher
(c) Dry powder fire extinguisher
(d) Water fire extinguisher
8
270What is flash point of a material?8
271Type of flame produced by a fuel depends upon
A. calorific value
B. amount of oxygen
c. type of fuel and its chemical composition
D. all of the above
8
2727.
Name the unit in which the calorific value of a fuel is
expressed.
8
273(C) NU,
(d) 02
13. The colour of luminous zone of a candle flame is
(a) black
(b) blue
en (c) yellow
(d) None of these
14 W11 12.11erine is ayamnle of snontanenus
8
2741 VILL
Fill in the blanks:
(a) Burning of wood and coal causes
of air.
(b) A liquid fuel, used in homes is
(c) Fuel must be heated to its
before it starts
burning
(d) Fire produced by oil cannot be controlled by
8
27518. Assertion: the substances classified as fuel must necessarily
contain one or several of the combustible elements
Reason: carbon, hydrogen, sulphur are combustible
substances.
8
2761.
Water can be used as fire extinguisher to put out –
(a) burning wood (b) burning oil
(c) burning cloth (d) burning charcoal
8
277Statement: Combustion can take place
at all temperatures less than an ignition temperature.
State whether the given statement is
true or false.
A. True
B. False
8
27815. Is rusting of iron a combustion process.
S
8
27911.
In an experiment 4.5 kg of a fuel was completely burnt. The
heat produced was measured to be 180,000 kJ. Calculate the
calorific value of the fuel.
8
280Yellow colour in the flame denotes
A. outermost part
B. middle zone
c. innermost zone
D. none of these
8
281Write any four characteristic of an ideal
fuel.
8
282Fire extinguisher’s containing ( C O_{2} ) is
the best extinguisher.
A. Because ( C O_{2} ) being heavier than oxygen, covers the fire like a blanket
B. Because ( C O_{2} ) being heavier than oxygen, increase fire
C. Because ( C O_{2} ) being leighter than oxygen, covers the fire like a blanket
D. None of these
8
283lu) TU T ous zone
10. Select the quality that a good fuel should possess.
(a) High calorific value
(b) A low calorific value
(c) It should burn too fast
(d) It should burn too slow.
8
284The heat liberated per kilogram of a fuel
is called its:
A. calorific value
B. mass value
c. weight value
D. money value
8
285Artificial rubies and sapphires can be made by heating alumina in?
A. An oxy-hydrogen flame
B. An oxy-acetylene flame
c. Burning methane
D. An electric furnace
8
286Carbon dioxide is used in fire
extinguishers.
8
287be used for small file UI ME II dll
Which of these fire extinguisher is most suitable for electrical
fires?
(a) CO2
(b) water
(c) wet chemical
(d) foam
8
288Which of the following elements give light green colour in flame test?
( mathbf{A} cdot K )
в. ( R b )
( c . C a )
D. ( B a )
8
28920
14. After polymerization Liquefied Petroleum Gas (LPG) is
converted to get
(a) Camphor
(b) Polymers
(c) Coal
(d) None of these
8
2907.
Your LPG gas stove at home is giving a yellow flame. What
can this mean?
8
291059001UUIU
AVEA
7.
………….. has corroded the marble structure of Taj Mahal.
8
292Why d-block element form complexes?
A. due to larger size and higher nuclear charge
B. due to small size and low nuclear charge
C. due to small size and higher nuclear charge
D. none of the above
8
293Can the process of rusting be called combustion? Discuss.8
294At ( 27^{circ} mathrm{C}, ) the combustion of ethane
takes place according to the reaction
[
begin{array}{c}
C_{2} H_{6}(g)+frac{7}{2} O_{2}(g) rightarrow 2 C O_{2}(g)+ \
3 H_{2} O(l)
end{array}
]
( Delta E-Delta H ) for this reaction at ( 27^{circ} mathrm{C} ) will
be:
A ( .+1247.1 mathrm{J} )
B. – 1247.1
c. – 6235.5 J
D . +6235.5 J
8

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