Expansion of Gases

Q.

What happens to pressure if temperature increases?

Q.

What happens to air when it is heated?

1. Contracts

2. Moves down

3. Expands

4. Movement ceases

Q.

Cold air is denser than warm air.

1. True

2. False

Q. In cold countries, water pipes burst sometimes, because _____.

1. pipe contracts
2. water expands on freezing
3. when water freezes, pressure increases
4. when water freezes, it takes heat from pipes

Q. A gas has volume V and pressure P. The total translational kinetic energy of all molecules of the gas is

Q.

The volumes of gases A, B, C, and D are in this ratio $1:2:2:4$ under the same conditions of temperature and pressure. If the volume of A is actually $5.6{\mathrm{dm}}^3$ at STP, calculate the number of molecules in the actual volume of D at STP (Avogadros number is $6\times {10}^{23}$). The volume of D is four times the volume of A as given.

Q. A gas follows $V{T}^2=$ const. Its volume expansion coefficient will be :-

1. $\frac{2}{T}$
2. $-\frac{2}{T}$
3. $\frac{3}{T}$
4. $-\frac{3}{T}$

Q. A gas is filled in a container of volume $V$ at ${121}^{o}C$. To what temperature should it be heated in order that $\frac{1}{4}th$ of the gas may escape out of the vessel ?

Q. $1$ mole of a gas with $\gamma =\frac{7}{5}$ is mixed with $1$ mole of gas with $\gamma =\frac{5}{3}$, the value of $\gamma$ of the resulting mixture of.

1. $\frac{7}{5}$
2. $\frac{2}{5}$
3. $\frac{3}{2}$
4. $\frac{12}{7}$

Q. If $T$ represent the absolute temperature of an ideal gas, the volume coefficient of thermal expansion at constant pressure, is :

1. $T$
2. $T^2$
3. $1/T$
4. $1/T^2$

Q. A cube of ice floats partly in water and partly in k.oil find the ratio of the volume of ice immersed in water

Q.

As the temperature of a gas increases, the volume occupied by the gas ___.

1. increases

2. decreases

3. remains constant

4. can increase or decrease

Q. Two vertical glass tubes filled with a liquid are connected at their lower ends by a horizontal capillary tube. One tube is surrounded by a bath containing ice and water at $0^{\circ }C$ and the other by hot water at $t^{\circ }C$. The difference in the height of the liquid in the two columns is $△h$, and the height of the column at $0^{\circ }C$ is $h_0$. Coefficient of volume expansion of the liquid is:

1. $\frac{△h}{h_{0}t}$
2. $\frac{2△h}{h_{0}t}$
3. $\frac{2h_0}{△ht}$
4. $\frac{h_0}{△ht}$

Q. Expansion during heating
(a) occurs in solids only
(b) causes decrease in weight
(c) is due to increase of interatomic spacing

1. only (a) is wrong
2. (a) & (b) are wrong
3. (a), (b) & (c) are wrong
4. (a) , (b) & (c) are correct

Q.

A gas in an airtight container is heated from ${25}^{\circ }C$ to ${90}^{\circ }C$. The density of the gas will:
( Consider there is a negligible expansion of container)

1. Increase slightly

2. Decrease slightly

3. Increase considerably

4. Remain the same

Q. Match the following in column A with column B
$\begin{array}{cc}\text{A}& \text{B}\\ \text{(1) Thermal expansion of solids}& \text{(P) Working of automobile engines}\\ \text{(2) Thermal expansion of liquids}& \text{(Q) Gaps kept in between rails}\\ \text{(3) Thermal expansion of gases}& \text{(R) Working of thermometer}\end{array}$

1. (1)-(Q), (2)-(R), (3)-(P)
2. (1)-(R), (2)-(Q), (3)-(P)
3. (1)-(Q), (2)-(P), (3)-(R)
4. (1)-(P), (2)-(Q), (3)-(R)

Q.

Match List I with List II

List-I List-II

a) Volume Coefficient of e) Jolly's apparatus

expansion of a gas

b) Pressure coefficeient f) Brownian motion

of expansion of a gas

c) Avagadro constant g) Clements and desormes

apparatus

d) Ratio of two specific h) Regnault's apparatus

heats of a gas

1. a-h, b-e, c-f, d-g.
2. a-g, b-f, c-h, d-e.
3. a-e, b-g, c-f, d-h.
4. a-f, b-h c-e, d-g.

Q.

A given amount of gas occupies 1000cc at 27${}^0$ C and 1200cc and 87${}^0$ c. What is its volume coefficient of expansion

1. ${\frac{1}{173}}^0{C}^{-1}$
2. ${\frac{1}{273}}^0{C}^{-1}$
3. ${173}^0{C}^{-1}$
4. ${273}^0{C}^{-1}$

Q. (a) Take the definition of the coefficient of volume expansion to be
$\beta =\frac{1}{V}\frac{dV}{dT}{|}_{p=constant}=\frac{1}{V}\frac{\delta V}{\delta T}$
Use the equation of state for an ideal gas to show that the coefficient of volume expansion for an ideal gas at constant pressure is given by $\beta =1/T$, where T is the absolute temperature. (b) What value does this expression predict for b at $0^{0}C$? State how this result compares with the experimental values for (c) helium and (d) air Note: These values are much larger than the coefficients of volume expansion for most liquids and solids.

Q.

A vessel contains 1 mole of an ideal monoatomic gas. The coefficient of volume expansion of the gas is $\alpha$. 2 moles of a diatmoic; ideal gas is then introduced into the same vessel. The coefficient of the volume expansion of the mixture will be

1. $\alpha$
2. $3\alpha /2$
3. $2\alpha /3$
4. $\alpha /3$

Q. Automobile engines work on the principle of:

1. thermal expansion of solids
2. thermal expansion of liquids
3. thermal expansion of gases
4. anomalous expansion

Q. One mole of n ideal monatomic gas undergoes the following four reversible processes:
Step I: It is first compresses adiabatically from volume $V_1$ to $1m^3$.
Step II: then expanded isothermally to volume $10m^3$.
Step III: then expanded adiabatically to volume $V_3$.
Step IV: then compressed isothermally to volume $V_1$.
If the efficiency of the above cycle is $3/4$ then V, is

1. $2m^3$
2. $4m^3$
3. $6m^3$
4. $8m^3$

Q. If at ${60}^{\circ }$C and $\text{80 cm}$ of mercury pressure, a definite mass of a gas is compressed slowly, then the final pressure of the gas if the final volume is half of the initial volume $(\gamma =\frac{3}{2}$) is:

1. $\text{120 cm of Hg}$
2. $\text{140 cm of Hg}$
3. $\text{160 cm of Hg}$
4. $\text{180 cm of Hg}$