Melting and Boiling Point of Water

Q.

What is the use of safety valve in a pressure cooker?

Q.

The presence of impurities decreases the boiling point of a liquid.

1. True
2. False

Q. Arrange the following in the correct order of increasing density.

1. Air
2. Oil
3. Water
4. Brick

Q.

It is easier to cook food in the pressure cookers because the boiling point of water increases with

1. decrease in pressure

2. increase in pressure

3. constant pressure

4. increase and then decrease in pressure

Q. Two objects, A and B have the same mass, but volume of A is more than that of B. Which object has a higher density?

1. B
2. Both objects are having same density.
3. Insufficient data.
4. A

Q.

The melting point of ice is same as the freezing point of water.

1. True
2. False

Q.

What is the principle used in a pressure cooker?

Q.

In general, substances shrink on cooling and their volume decreases. This increases its:

1. boiling point

2. freezing point

3. heat capacity

4. density

Q. The density of water is maximum at ____${}^{\circ }$ C.

1. 4

Q. 1 kg of ice at -10 degree Celsius mixed with 4.4kg water at 30 degree. Final temperature of mixture is

Q.

How do insects such as pond skaters stay afloat on water?

1. The high surface tension of water.

2. They can swim.

3. Water is denser than the pond skater.

4. They are denser than water.

Q.

Explain why an iron nail sinks into the water while a cork does not sink into water?

Q. The boiling point of water is ____ .

1. ${20}^{0}C$
2. ${50}^{0}C$
3. ${80}^{0}C$
4. ${100}^{0}C$

Q. The latent heat of fusion converts phase to phase.

1. solid
2. liquid
3. gaseous
4. plasma

Q.

A chemistry teacher demonstrates the effect of impurities on the boiling point of water using the arrangement of apparatus as shown below :

What could be the probable thermometer reading recorded during the experiment?

1. $0^{\circ }C$

2. ${100}^{\circ }C$

3. ${102}^{\circ }C$

4. ${99}^{\circ }C$

Q.

What will happen to its boiling point If you add impurities to water?

1. Increases

2. Decreases

3. Remains same

4. First increase then decrease

Q. When the ice cubes are heated, the temperature at the melting point until the ice melts completely.

1. increases
2. decreases
3. remains constant

Q.

The temperature at which a solid gets converted to a liquid is called the_____.

1. Melting point

2. Boiling point

3. Fusion point

4. Fission point

Q. In which of the following processes, change in the state of matter involves gaining of heat?

1. Boiling
2. Freezing
3. Condensation
4. Melting

Q.

Water that is fit for drinking is appropriately called _____ water.

1. ground
2. distilled
3. potable
4. bottled

Q.

Give the effect of pressure in our day to day life activities while cooking?

Q. What is melting points?

Q. Identify the water bodies that participate in water cycle.

1. Lakes
2. Oceans
3. Ponds
4. Rivers

Q. Madhu bought a jar of coconut oil. She used it regularly in summer. But, the oil did not come out of the jar in winter. What can be the reason for this?

1. Freezing
2. Sublimation
3. Melting
4. Boiling

Q. The temperature at which water gets converted to steam is known as its .

1. freezing point
2. melting point
3. boiling point

Q.

29. Why does river contains lots of impurities?

Q.

A ship dips in water __________ in summer than in winter (more /less ).

Q. Which among the following are not a source of fresh water?

1. Rivers
2. Oceans
3. Lakes
4. Seas