Factors Affecting Boiling Point

Q.

What is the effect of an increase in pressure on the boiling point of a liquid?

Q.

Water boils at ${120}^{o}C$ in a presure cooker. Explain the reason.

Q. What is the role of anomalous behaviour of water in preserving aquatic life in regions of cold climate?

Q.

Why does boiling point decrease with the vapour pressure?

Q. If the pressure is reduced from the atmospheric pressure to a lower pressure, water will boil at a temperature ____.

1. $>100{}^{\circ }\text{C}$
2. $=100{}^{\circ }\text{C}$
3. Data insufficient
4. $<100{}^{\circ }\text{C}$

Q.

The boiling point of liquid ______ with an increase in pressure.

1. remains unchanged

2. increases or decreases

3. decreases

4. increases

Q.

How is the boiling point of water affected when some salt is added to it?

Q. When common salt is added to water, the boiling point of water increases.

1. True
2. False

Q. How is the boiling point of water affected when some salt is added to it?

Q. The boiling point of a liquid _______ by the addition of soluble impurities to it.

1. increases
2. decreases
3. remains the same
4. varies randomly

Q.

Write down the approximate range of temperature at which water boils in a pressure cooker.

Q.

A pressure cooker is based on the principle that boiling water increases with the_______.

1. Increase in temperature

2. Decrease in pressure

3. Increase in volume

4. Increase in pressure

Q.

Choose the correct option/options:

1. The boiling point of a liquid increases with the increase in pressure.

2. The boiling point of a liquid decreases with the increase in pressure

3. The boiling point of a liquid increases by the addition of impurities to it.

4. The boiling point of a liquid decreases by the addition of impurities to it.

Q.

The boiling point of a liquid decreases by the addition of impurities to it.

1. False

2. True

Q.

Given that P, V and T stand for vapour pressure, volume and temperature, an ideal gas obeys the law -PV α T. If the volume is kept constant, P α T. With decreasing temperature the vapour pressure drops, until P = 0 at some temperature T₀. Since P cannot be less than zero, or negative, T₀ naturally becomes the lowest temperature that we can reach, and can be used as a "natural” lower fixed point while constructing a temperature scale. This is the "absolute zero”, which in the Celsius scale is - 273.15⁰C.

To construct an absolute temperature scale , where the absolute zero is naturally 0. Let us choose the triple point of mercury (-38.8⁰C, at 0.2 mPa) as our upper fixed point, and give assign it a value 100. What will be the boiling point of water on this scale?

1. 159.2

2. 121.5

3. 110

4. 182.7

Q.

The ideal gas law, which relates the P, V and temperature T of an ideal gas in a closed box, given as PV = nRT, can be manipulated to construct an effective thermometer. A "constant volume gas thermometer” uses a sample of gas (commonly, nitrogen or helium) in a closed chamber, thus fixing the volume V. The temperature is then measured by reading off the corresponding pressure P. At the freezing point of water, it is seen that a gas thermometer records a pressure of 0.9 x 10⁵ Pa; it also records a pressure of 1.2 x 10⁵ Pa at the boiling point of water. What pressure will you find in the gas chamber at a room temperature of 23⁰C?

1. 0.81 x 10⁵ Pa

2. 1.34 x 10⁵ Pa

3. 0.64 x 10⁵ Pa

4. 0.97 x 10⁵ Pa.

Q.

What will happen to the boiling point of a liquid, when we increase the pressure?

1. The boiling point increases.

2. The boiling point remains the same.

3. The boiling point decreases.

4. The boiling point either increases or decreases.

Q. The absorption of heat happens in which of these processes that represent a change in state:
(1) Boiling (2) Freezing (3) Condensation (4) Melting

1. 1 and 2
2. Only 1
3. 1, 2, and 3
4. 1 and 4

Q.

Boiling point curve of a liquid at a particular pressure is given in the figure below:

Choose the correct boiling curve, when we decrease the pressure.

1. None of these

2. 

3. 

4. 

Q. What is the role of anomalous behaviour of water in preserving aquatic life in regions of cold climate?

Q. Which of the following is a correct relation for P' and P'' shown in the graph?

1. 
   P' > P''
2. 
   P' < P''
3. 
   P' = P''
4. 
   P' = 2P''

Q. ntQ.3n ntA water sample contains 9.5% MgCl2and 11.7% NaCl (by weight). Assuming 80% ionisation of each salt. Boiling point of water will be approximately (Kb= 0.52)n

Q. What is nerst equation

Q.

What is the principle of working of pressure cooker?

Q.

How the impurities present in a liquid affect its boiling point ?

Q. A beaker of water is placed on a table. It can be made to boil quickly by passing

1. steam through it by atmosphere pressure
2. steam through it at a pressure lower than atmospheric
3. steam through it at a pressure higher than atmospheric
4. hot water

Q. The boiling point of water can change due to different reasons. Pick the correct ones from below:

1. It decreases with increase in pressure.
2. It increases with increase in altitude.
3. It increases on the addition of impurities.
4. It decreases with an increase in altitude.

Q. Assertion: In a pressure cooker the water is brought to boil. The cooker is then remove from the stove. Now on removing the lid of the pressure cooker, the water starts boiling against.
Reason: The impurities in water bring down its boiling point

1. If both assertion and reason are true but the reason is the correct explanation of assertion.
2. If both assertion and reason are true but the reason is not the correct explanation of assertion.
3. If both the assertion and reason are false.
4. If reason is true but assertion is false.
5. If assertion is true but reason is false.

Q. The presence of soluble salt in water:

1. increases its melting point
2. decreases its boiling point
3. increases its boiling point
4. has no effects on its boiling point

Q. Sea water and river water are heated until they start boiling. Then which of the following options is correct

1. river water boils at lower temperature.
2. sea water boils at lower temperature.
3. both boil at the same temperature.
4. cannot be said