Compressibility Factor

Q.

The compressibility factor for a real gas at high pressure is

1. 

2. 

3. 

4. 

Q. Solid balls of radius 17.32 cm crystallises in bec pattern, during one such crystallisation some oxygen gas is trapped. This trapped oxygen at 640K creates pressure of 5 atm Assume:(i) BCC arrangement is not disturbed due to trapping of gas.(ii) Gas is uniformly distributed inside unit cell\lbrack Take R 0.08 atm-litre/mole-K, N_a =6 x 10^{23}, Mass of a solid ball =64g. 1) Calculate number of oxygen molecules present in a unit cell 2) Calculate percentage increase in density due to trapping of ga

Q. Compressibility factor for $H_2$ behaving as real gas is:

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

Q.

On a certain humid day, the mole fraction of the water vapour in air at ${25}^{\circ }C$ is 0.0287. If total pressure of air is 0.977 bar, calculate the partial pressure of water vapour in air and relative humidity if the vapour pressure of water at ${25}^{\circ }C$ is 0.0313 bar. The partial pressure of water vapour ($P_{H_{2}O}$) and relative humidity ($R_H$) respectively are:

1. 

2. 

3. 

4. 

Q. A box of negligible mass containing 2 moles of andeal gas of molar mass M and adiabatic exponent29ideal gas of molar imoves with constant speed v on a smoothhorizontal surface. If the box suddenly stops, therchange in temperature of gas will be

Q. 2 moles of a gas at temperature T and volume V are heated to twice its volume at cons†an t pressure.If gamma is the adiabatic cons†an t , then increase in internal energy of the gas is?

Q.

The temperature to which a gas must be cooled before it can be liquefied by compression is called as___.

1. Boyle's temperature

2. Critical temperature

3. Liquefaction temperature

4. Inversion temperature

Q.

Negative deviation from ideal behaviour is due to fact that :

1. There exist molecular interaction and PV/nRT>1.

2. There exist molecular interaction and PV/nRT<1.

3. Atoms have finite size and PV/nRT>1.

4. Atoms have finite size and PV/nRT<1.

Q.

If one mole of a gas (mol.wt-40) occupies a volume of 20litres, under the same conditions of temperature and pressure the volume occupied by 2 moles of gas B (mol.wt=80) is

1. 80 L

2. 50 L

3. 60 L

4. 40 L

Q. 1 mole of an ideal gas is compressed isothermally and reversibly at 298 K from a pressure of 1 Pa. To do a work of 100J, to what final pressure should we compress it? (R = 8.314 J/K/mol)

1. 1.0412 Pa
2. 0.96 Pa
3. 10 Pa
4. 96 Pa

Q. The compressibility factors for 1 mole of real gases at low pressure, high pressure and that of gases of very low molar masses are $Z_1,Z_2$ and $Z_3$. These are

1. $Z_1=(1-\frac{a}{RTV}),Z_2=(1+\frac{Pb}{RT}),Z_3=1$
2. $Z_1=(1-\frac{a}{RTV}),Z_2=1,Z_3=(1+\frac{Pb}{RT})$
3. $Z_1=(1+\frac{Pb}{RT}),Z_2=(1-\frac{a}{RTV}),Z_3=(1+\frac{Pb}{RT})$
4. $Z_1=(1-\frac{a}{RTV}),Z_2=(1+\frac{Pb}{RT}),Z_3=(1+\frac{Pb}{RT})$

Q. 10 ml of the gaseous mixture of CO, H2 andNH3, are completely oxidised by 8 ml O2. If theoriginal mixture of CO, H2 and NH3 containsequal volumes of CO and H2, then what is thevolume % of NH, in the original mixture ?(1) 10% (2) 20% (3) 40% (4) 60%

Q. equal masses of H2 O2 and CH4 have been taken in a continer of vol v and temp 25^0c in identical condition .the ratio of the volumes of gases H2:O2 :CH4 wouldbe

Q. vapour density of mixture of NO2 and N2O4 is 34.5 , then percentage abudance(by mole) if NO2 in mixture i

Q. pressure exerted by one mole of an ideal gas kept in a vessel of V L havong root mean square speed of molecules v and m mass of each molecule is correctly given by the equatio

Q.

The compressibility factor of a gas is less than 1 at STP. Its molar volume Vm will be

1. Vm > 22.42

2. Vm < 22.42

3. Vm = 22.42

4. None

Q.

For CO, isotherm is of the type as shown in the figure.Near the point A , compressibility factor Z will be___.

1. 

2. 

3. 

4. 

Q. In Vanderwaals gas equation, the term that accounts for the volume occupied by n mole molecules is (1) V-nb (2)an^2/V^2 (3)nb (4)P+ (an^2/V^2)

Q.

$C_P-C_V=R$. Is the given statement

1. True

2. False

Q.

The compressibility factor for an ideal gas is

1. 1.5

2. 1.0

3. 2.0

4. ∞

Q. The compressibility factor (Z) of a gas is less than unity at STP. Therefore,

1. $V_m<22.4$ litres
2. $V_m=22.4$ litres
3. $V_m=44.8$ litres
4. $V_m$$>$$22.4$ litres

Q. If the compressibility factor of $H_2$ is $1.8$, then the volume of one mole of real $H_2$ at STP will be:

1. $40.32L$
2. $22.42L$
3. $30.322L$
4. $12.44L$

Q. The sketch shows the plot of Z vs P for 1 mole of a hypothetical gas at three distinct
temperatures:

Boyle's temperature is the temperature at which a gas shows ideal behaviour over a
pressure range in the low pressure region. Boyle's temperature $\left(T_b\right)=\frac{a}{Rb}$. If a plot is
obtained at temperatures well below Boyle's temperature, then the curve will show a negative deviation in the low pressure region and a positive deviation in the high pressure
region.

In the first figure, in the plot at $500K,Z$ changes from 2 to 2.2 as the pressure varies from 1000 atm to $1200\text{atm}$ (high pressure). The value of $\frac{b}{RT}$ will be:

1. ${10}^{-3}at{m}^{-1}$
2. $2\times {10}^{-3}at{m}^{-1}$
3. $5\times {10}^{-4}at{m}^{-1}$
4. ${10}^{-4}at{m}^{-1}$

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. 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 van der Waals' constant ${}^{\prime }{a}^{\prime }$ for different gases have been given as:

Gas	$a\left(atm{L}^{2}mo{l}^{-2}\right)$
$O_2$	$1.36$
$N_2$	$1.39$
$C{H}_4$	$2.25$
$N{H}_3$	$4.17$

The gas that can be most easily liquefied is:

1. $O_2$
2. $C{H}_4$
3. $N_2$
4. $N{H}_3$

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. At $0.1atm$ and ${25}^{\circ }C$, compressibility factor of four gases $A,B,C$ and $D$ are $0.25,1.3,1and0.7$ respectively. The gas which is most easily liquifiable at ${25}^{\circ }C,$ will be.

1. $D\left(g\right)$
2. $C\left(g\right)$
3. $B\left(g\right)$
4. $A\left(g\right)$

Q. what is critical temperature? how is it related to van der waal constant a

Q.

2gm of $O_2$ at 27${}^{\circ }$C and 760 mm of Hg pressure has volume

1. 22.4 lit.

2. 1.5 lit.

3. 2.8 lit.

4. 11.2 lit.