Ignition Temperature

Q. What is the difference between flammable and inflammable?

Q.

Give examples of inflammable substances.

Q. Water contains hydrogen then why doesn't it burn?

Q.

Which of the following is an inflammable substance?

1. Water
2. Petrol
3. Cement
4. Glass

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

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

Q.

The picture below shows two cases in which a person is trying to burn the paper cup. In case 1, the cup has water in it and in case 2, it is empty and dry. Identify in which of the cases the paper will burn.

1. Case 1

2. Case 2

3. Both case 1 and case 2

4. The paper doesn't burn in both the cases.

Q. When we heat an empty paper cup it catches fire easily. But when we try to heat a paper cup with water, it does not catch fire. When we add water into the paper cup, its ignition temperature _____.

1. None of the above
2. increases
3. remains constant
4. decreases

Q. The picture below shows two cases in which a person is trying to burn the paper cup. In case 1, the cup is filled with water and in case 2, it is empty and dry. Which of the following statements is true about this activity?

1. Case 1 catches fire
2. Case 2 catches fire
3. Case 1 does not catch fire
4. Case 2 does not catch fire

Q. Fuels A, B, C and D have ignition temperatures of 44${}^0\text{C}$, 53${}^0\text{C}$, 64${}^0\text{C}$ and 88${}^0\text{C}$ respectively. Which of the given fuels will burn at 60${}^0\text{C}$?

1. A
2. B
3. C
4. D

Q.

The substances which have very low __________ temperature and can easily catch fire with a flame are called __________ substances.

Q. An object having high ignition temperature is considered good or bad and why?

Q. Fill in the blanks using the words given in the box.​

ignition, petrol, combustion, calorific value, combustible, inflammable​

(a) A chemical process in which a substance reacts with oxygen to give off heat is called ______.​
(b) Wood, paper, CNG are __________ substances.
(c) The lowest temperature at which a substance catches fire is called its ______ temperature.​
(d) Ignition temperature of _______ is lower than that of wood.
(e) The substances which have very low _______ temperature and can easily catch fire with a flame are called _______ substances.
(f) The amount of heat energy produced on complete combustion of 1kg of a fuel is called its ______.

Q. A substance with an ignition temperature of 55${}^0$C will undergo spontaneous combustion at room temperature.

1. True
2. False

Q.

Kerosene is an example of a/an ______[inflammable/flammable] substances.

Q. Burning of green leaves takes longer time as compared to burning of dry leaves. Which of the following are the reasons behind this?

1. Green leaves have lower ignition temperature
2. Green leaves have higher ignition temperature
3. Water quantity in green leaves is lesser than dry leaves
4. Water quantity in green leaves is higher than dry leaves

Q. What is ignition temperature?

Q.

A fire propagates because during burning:

1. A portion of heat released is utilised to maintain the ignition temperature.

2. A portion of heat released is utilised to melt the substance.

3. A portion of heat released is utilised to vapourise the substance.

4. A portion of heat released is utilised to decrease the ignition temperature of the substance.

Q. What is the difference between inflammable substances and combustible substances?

Q.

The temperature of the flame of a candle is above the ignition temperature of the wax.

1. True

2. False

Q.

A fire propagates because during burning

1. A portion of heat released is utilised to maintain the ignition temperature.

2. A portion of heat released is utilised to boil the substance.
3. A portion of heat released is utilised to vapourise the substance.
4. None of above

Q. Maam is there any difference between flammable and inflammable substances?

Q.

Why are some substances inflammable ? Why are perfumes and orange peels flammable

Q.

Why doesn't the paper burn in case 1 whereas it does in case 2? [3 MARKS]

Q.

The substances which have very low

---

temperature and can easily catch fire with a flame are called

---

substances.

Q. A candle wick burns with a flame but a charcoal does not burn with a flame instead it produces smoke. Why?