Inflammable Substances

Q.

Which of the following fuels has the highest calorific value?

1. Petrol

2. Hydrogen

3. LPG

4. Natural gas

Q. Volume at NTP of oxygen required to completely burn 1 kg of coal(100%carbon) A-22.4L B-22400L C-1860L D-1000L

Q. The process of rusting can be known as combustion.

1. True
2. False

Q.

A gas stove converts ________ energy into heat energy.

1. Chemical

2. kinetic

3. Potential

4. Gravitational

Q.

The chemical reaction in which heat and light are produced is called___.

1. Combustion

2. Rusting

3. Decomposition

4. Deposition

Q. The percentage by volume of C3H8 in gaseous mixture of C3H8, CH4, CO is 20. Calculate the volume of CO2 produced by complete combustion under similar condition 1. 90 ml 2. 160ml 3. 140ml 4. 200ml

Q. Water, earth, air, ether and are the five elements that compose life.

1. smoke
2. flame
3. fire
4. soil

Q.

What do you understand by calorific value? Arrange the following fuels in their ascending order of calorific value : hydrogen, methane, cow dung cake, kerosene, wood. [3 MARKS]

Q. what volume of oxygen gas at 0 degree Celcius and 1 atm is needed to burn 1L of propane gas measured under same conditions??

Q. What would be percentage composition by volume of a mixture of CO and CH4 whose 10.5mL requires 9mL oxygen for complete combustion?

Q. Given below is a sign that is seen on a box at a petrol filling station. What does this sign indicate?

1. High calorific value
2. Non-combustible substance
3. Fire extinguisher
4. Inflammable substance

Q.

Which of the following is not used in making matchsticks these days ?

(a) potassium chlorate

(b) white phosphorus

(c) antimony trisulphide

(d) red phosphorus

Q.

The calorific value of wood is higher than that of coal (True or False). Also, write the false statements in their correct form.

1. True
2. False

Q.

A heap of green leaves is lying in one corner of a park. The green leaves in the heap burn with difficulty because :

(a) they contain a tough material called cellulose

(b) they contain a lot of water

(c) they contain a green pigment chlorophyll

(d) they do not get sufficient oxygen for burning

Q.

A type of oxidation in which a substance reacts with oxygen rapidly to release a large amount of heat and light energy.

Q.

Which inert gas is used in the advertisement hoarding shown in the given picture?

1. Krypton

2. Radon

3. Argon

4. Neon

Q.

White phosphorus burns in air spontaneously.

1. True

2. False

Q. Water, earth, air, ether and are the five elements that compose life.

1. smoke
2. flame
3. fire
4. soil

Q. The unit of calorific value of a fuel is ?

1. °C
2. L
3. m/s
4. kJ/kg

Q. Nicky collected two different types of fuels A and B. She wants to find out which fuel is the most efficient among the fuels she has collected. She burns 6 kg of A and 8 kg of B completely. She found out that the heat produced by complete burning of A and B is 3600 kJ and 4000 kJ respectively. Which of the following are true regarding fuel efficiency and calorific value of the fuels A and B ?

1. Fuel efficiency of A is more than B
2. Fuel efficiency of A is less than B
3. Calorific value of A is more than B
4. Calorific value of A is less than B

Q.

Why is petrol not preferred for domestic use?

Q. If the temperature of a burning substance falls below its ignition temperature, the following observation holds true:

Q. Given below is a sign that is seen on a box at a petrol filling station. What does this sign indicate?

1. Non-combustible substance
2. Inflammable substance
3. High calorific value
4. Fire extinguisher

Q. Choose the correct statement about inflammable substances from the following. They have

1. High ignition temperature and cannot catch fire easily.
2. Low ignition temperature and can catch fire easily.
3. High ignition temperature and can catch fire easily.
4. Low ignition temperature and cannot catch fire easily.

Q. What volume of gas (O2) measured at 0^°C and 1 atm, is needed to burn completely 1 L of propane gas C3H8 measured under the same conditions?

Q.

Fill in the blank with the suitable word:

Keep _______ chemicals away from the burner.

Q. Which of the following options is true for substances having very low ignition temperature?

1. They catch fire after some time.
2. They always release sulphur dioxide.
3. They catch fire easily.
4. They will not catch fire.

Q. Choose the correct statement about inflammable substances from the following.
They have:
[1 mark]
[NCERT Exemplar Q.9]
[Ignition temperature]

1. high ignition temperature and can catch fire easily
2. high ignition temperature and cannot catch fire easily
3. low ignition temperature and can catch fire easily
4. low ignition temperature and cannot catch fire easily

Q. Identify the correct option regarding the ignition temperature of an ideal fuel.

1. Ignition temperature should be below room temperature.
2. Ignition temperature should be above room temperature.
3. Ignition temperature should be equal to room temperature.
4. Ignition temperature should be equal to ${100}^{\circ }$C.

Q. Ignition temperature of flammable substances is _____________.

1. high
2. very high
3. low
4. None