Boiling

Q.

Differentiate between

Boiling point and Condensation point.

Q.

The saturation vapour pressure of water at 100°C is

1. 750 mm of mercury

2. 739 mm of mercury

3. 760 mm of mercury

4. 712 mm of mercury

Q.

Differentiate between Celsius scale and Fahrenheit scale.

Q. two uniform charged spherical drops each at a potential V coalesce to form a larger drop. if the capacity of each smaller drop is C then find the capacity and potential to larger drop

Q.

Boiling point of water at normal atmospheric pressure is.

1. 0$°$C

2. 100$°$C

3. 37$°$C

4. 357$°$C

Q.

Evaporation is a __________ phenomenon whereas Boiling is a __________ process.

1. surface, throughout

2. surface , surface

3. throughout, surface

4. none

Q.

Find the heat energy required to boil $5kg$ of water if its initial temperature is ${30}^{0}C$. (specific heat of water is $4200JK{g}^{-1}{K}^{-1}$ and boiling point is ${100}^{0}C$).

Q.

The saturation vapour pressure of water at ${100}^{o}C$ is

1. 739 mm of mercury

2. 750 mm of mercury

3. 760 mm of mercury

4. 712 mm of mercury

Q.

At high altitudes, water boils above ${100}^{°}C$.

1. True
2. False

Q. At what external pressure will water boil ${140}^{\circ }C$? (S VP at ${140}^{\circ }C$ =2710 mmHg)

1. 2.53
2. 3.56
3. 1
4. None

Q. if vapour pressure inversely prop to boiling point?

Q. Boiling point of water at normal atmospheric pressure is ______.

1. $0^{\circ }C$
2. ${110}^{\circ }C$
3. $-4^{\circ }C$
4. ${100}^{\circ }C$

Q. $1atm$ of pressure is equal to

1. $\frac{1}{760}Torr$
2. $1Torr$
3. $1.013\times {10}^{5}Torr$
4. $760Torr$

Q. On increasing the external pressure , the boiling point of liquid

1. is raised
2. is lowered
3. remain unaffected
4. uncertain

Q.

Water kept in an open bowl will quickly evaporate on the moon. Do you agree? Explain logically.

Q.

In which of the following temperature scales is the value of boiling point of water negative?

1. Fahreinheit scale

2. Kelvin scale

3. Celsius scale

4. None of these

Q. A hypothetical screw gauge has a pitch of $0.2\text{mm}$ and $10$ divisions on circular scale. The least count of screw gauge is

Q. The temperature at which a liquid is converted into vapour (gas) is called boiling point.

1. True
2. False

Q. Water at normal atmospheric pressure boils at :

1. $250K$
2. ${100}^{\circ }C$
3. $0^{\circ }C$
4. ${50}^{\circ }C$

Q. Boiling is a surface phenomenon.

1. True
2. False

Q. Boiling of liquid can take place at any temperature.

1. True
2. False

Q.

What is the physical state of water at:

$100°\mathrm{C}$

Q. The process during which a liquid on heating changes to vapour state is called boiling.

1. True
2. False

Q. When $1g$ of water at ${100}^{\circ }C$ gets converted into steam at the same temperature, the change in volume is approximately :

1. $1cc$
2. $1000cc$
3. $1500cc$
4. $1670cc$

Q. How much heat energy is gained when 5 kg of water at ${20}^{\circ }C$ is brought to its boiling point?

1. 1680 KJ
2. 1700 KJ
3. 1720 KJ
4. 1740 KJ

Q. A constant-volume thermometer registers a pressure of 1.500 × 10⁴ Pa at the triple point of water and a pressure of 2.050 × 10⁴ Pa at the normal boiling point. What is the temperature at the normal boiling point?

Q. A J-tube shown in the figure contains a volume V of dry air trapped in arm A of the tube. The atmospheric pressure is H cm of mercury. When more mercury is poured in arm B, the volume of the enclosed air and its pressure undergo a change. What should be the difference in mercury levels in the two arms so as to reduce the volume of air to V/2?

1. $\frac{H}{2}$ cm
2. $\frac{H}{30}$ cm
3. H cm
4. 2 H cm

Q. 25 degree celcius is equal to ?

1. 77 Fahrenheit
2. 85 Fahrenheit
3. 100 Fahrenheit
4. 120 Fahrenheit

Q. Write true or false for the statement :
Boiling is a rapid phenomenon.

1. True
2. False

Q. Explain why cooking is faster in a pressure cooker.