Compressibility Factor

Q. At low pressures (For 1 mole), the van der Waals equation is written as $[p+\frac{a}{V^2}]V=RT$ The compressibility factor is then equal to:

1. $(1-\frac{a}{RTV})$
2. $(1-\frac{RTV}{a})$
3. $(1+\frac{a}{RTV})$
4. $(1+\frac{RTV}{a})$

Q. A gas at 350 K and 15 bar has molar volume 20 percent smaller than that for an ideal gas under the same conditions. The correct option about the gas and its compressibility factor (Z) is:

1. Z > 1 and attractive forces are dominant
2. Z > 1 and repulsive forces are dominant
3. Z < 1 and attractive forces are dominant
4. Z < 1 and repulsive forces are dominant

Q.

The compressibility factor for an ideal gas is ?

1. 1.5

2. 1.0

3. 2.0

Q.

2 Moles Of PCl₅ were heated in a closed vessel of 2 Litre capacity. At equilibrium, 40% Of PCl₅ Is dissociated Into PCl₃ And Cl₂. What is the value of the equilibrium constant?

Q. The compression factor (compressibility factor) for 1 mole of a van der Waals' gas at $0{}^{\circ }C$ and 100 atmospheric pressure is found to be 0.5. Assuming that the volume of a gas molecule is negligible, calculate the van der Waals' constant 'a' (in $L^{2}mo{l}^{-1}atm$)

Q. The mole fraction of urea in an aqueous urea solution containing $900g$ of water is $0.05$. If the density of solution is $1.2gc{m}^{-3}$, the molarity of urea solution is

Q.

Compressibility factor, Z of a gas is given as $Z=\frac{pV}{nRT}$

(i) What is the value of Z for an ideal gas?

(ii) For real gas what will be the effect on value of Z above Boyle's temperature?

Q. The compressibility of a gas is less than unity at STP. Therefore, its molar volume is

1. $V_m=22.4\text{L}$
2. $V_m=44.8\text{L}$
3. $V_m>22.4\text{L}$
4. $V_m<22.4\text{L}$

Q. Calculate the compressibility factor for $C{O}_2$, it one mole of it occupies 0.4 L at 300K and 40 atm.

1. 0.85
2. 0.65
3. 0.99
4. 1

Q.

The compressibility factor is always greater than 1 and increases with increase in pressure for hydrogen and helium. (True or False)

1. True

2. False

Q.

The Van der Waal's Equation for 'n' moles of a real gas will be :

1. 

2. 

3. 

4. 

Q. The compressibility factor of nitrogen at 330 K and 800 atm is 1.90 and at 570 K and 200 atm is 1.10. A certain mass of $N_2$ occupies a volume of 1 $d{m}^3$ at 330 K and 800 atm. Calculate the volume occupied by the same quantity of $N_2$ gas at $570\text{K}$ and $200\text{atm}$.

1. 2 L
2. 1 L
3. 3 L
4. 4 L

Q.

The formation of micelles takes places above a particular temperature, called as:

1. CMC

2. Boiling point

3. Specific temperature

4. Kraft temperature

Q. The real gas equation at high pressure will be:

1. $PV+Pb=RT$
2. $PV-Pb=RT$
3. $PV-Pb=-RT$
4. $PV+Pb=-RT$

Q. The compressiblity factor (Z) for 1 mole of a real gas at low pressure can be written as:

1. $Z=1+\frac{RT}{Pb}$
2. $Z=1-\frac{a}{VRT}$
3. $Z=1-\frac{Pb}{RT}$
4. $Z=1+\frac{a}{VRT}$

Q.

In what ways is liquid fuel superior to solid fuels?

Q.

Gases deviate from the ideal gas behaviour because their molecules

1. Possess negligible volume

2. Have forces of attraction between them

3. Are polyatomic

4. Are not attracted to one another

Q. The density of steam at $27{}^{\circ }C$ and $8.3174\times {10}^4$ pascal is $0.8kg{m}^{-3}$. The compressibility factor would be

1. 0.75
2. 1
3. 0.88
4. 1.1

Q. Why vapour density of a gas is in relation with that of hydrogen gas ????

Q. If the temperature of the gas is lower than Boyle's temperature, $T_B$, then

1. At very low pressure $Z$ decreases with pressure
2. At the very low pressure $Z$ increases with pressure
3. At the very high pressure $Z$ decreases with pressure
4. $Z$ becomes independent of the pressure.

Q.

What are non ideal gases?

Q. Which set of conditions represents easiest way to liquefy a gas

1. Low temperature and high pressure
2. Low temperature and low pressure
3. High temperature and high pressure
4. High temperature and low pressure

Q.

Two gases that are lighter than air?

Q. The equation of state of a gas is $P(V-nb)=nRT$, where $b$ and $R$ are constants. If the pressure and the temperature are such that $V_m=10b,$ what is the value of compressibility factor?

1. $\frac{11}{10}$
2. $\frac{10}{11}$
3. $\frac{10}{9}$
4. $\frac{9}{11}$

Q. Fill in the blanks type
The equation of state for real gas is given by $(P+\frac{a}{V^2})\times (v-b)=RT$. The dimensions of the constant a are ______.

Q.

Does increasing volume increase concentration?

Q.

The density of mercury is $13.6\raisebox{1ex}{$g$}\!\left/ \!\raisebox{-1ex}{$c{m}^3$}\right.$ at $0^{°}C$ and its coefficient of cubical expansion is $1.82\times {10}^{-4}°C^{-1}$. Calculate the density of mercury at $50°C$.

Q.

The compressibility of a gas is less than unity at STP. Therefore?

1. ${\mathrm{V}}_{\mathrm{m}}$ greater than $22.4\mathrm{L}$

2. ${\mathrm{V}}_{\mathrm{m}}$ less than $22.4\mathrm{L}$

3. ${\mathrm{V}}_{\mathrm{m}}$ equal to $22.4\mathrm{L}$

4. ${\mathrm{V}}_{\mathrm{m}}$ equal to $44.8\mathrm{L}$

Q. The curve of pressure volume (PV) against pressure (P) of the gas at a particular temperature is as shown, according to the graph which of the following is /are incorrect (in the low pressure region):

1. $H_2$ and $He$ show positive deviation from ideal gas equation.
2. $C{O}_2,C{H}_4$ and $O_2$ show negative deviation from ideal gas equation.
3. $H_2$ and $He$ show negative deviation while $C{O}_2,C{H}_4$ and $O_2$ show positive deviation.
4. $H_2$ and He are less compressible than that of an ideal gas while $C{O}_2,C{H}_4$ and $O_2$ more compressible than that of ideal gas.

Q. Two van der Waals' gases have the same value of 'b' but different values of 'a', then which of the following statement is correct under similar conditions?

1. Both gases will occupy same volume
2. Gas having a larger value of 'a' will occupy less volume
3. Gas having a larger value of 'a' will occupy larger volume
4. Cannot be predicted