1. 4.4 g of a gas at STP occupies a volume of 2.24 L, the gas can
a) \[O_{2}\]
b) CO
c) \[ NO_{2}\]
d) \[ CO_{2}\]
Discussion
Explanation: 44g at STP occupies volume 22.4 litre which is molecular mass of CO2. Molecular mass occupies 22.4 litre at STP
2. If the four tubes of a car are filled to the same pressure with \[N_{2},O_{2},H_{2} and Ne\] separately, then which one will be filled first ?
a) \[N_{2}\]
b) \[O_{2}\]
c) \[H_{2}\]
d) Ne
Discussion
Explanation: Lesser the density more is the volume and H2 has lowest density. ( d = \[\frac{MP}{RT}\] at constant P, R and T, d \[\propto\] M )
3. When the product of pressure and volume is plotted against pressure for a given amount of the gas, the line obtained is
a) parallel to X-axis
b) parallel to Y-axis
c) linear with positive slope
d) linear with negative slope
Discussion
Explanation: Plot of PV vs P at constant T is parallel to X axis.
4. Air at sea level is dense. This is a practical application of
a) Boyle’s law
b) Charle’s law
c) Kelvin’s law
d) Brown’s law
Discussion
Explanation: d \[\propto\] p, Boyle’s law, d = \[\frac{MP}{RT}\] . At sea level pressure is more, hence density of air is more
5. Use of hot air balloons in sports and meteorological observations is an application of
a) Boyle’s law
b) Charle’s law
c) Kelvin’s law
d) Gay-Lussac’s law
Discussion
Explanation: Hot air is lighter due to less density (Charle’s law) (d = \[\frac{MP}{RT}\] )
6. “Equal volumes of all gases at the same temperature and pressure contain equal number of particles.” This statement is a direct consequece of
a) Perfect gas law
b) Avogadro’s law
c) Charle’s law
d) Boyle’s law
Discussion
Explanation: When P, V and T are same no. of particles will also be same (Avogadro law)
7. If 300 ml of a gas at 270 C is cooled to 70 C at constant pressure, its final volume will be
a) 135 ml
b) 540 ml
c) 350 ml
d) 280 ml
Discussion
Explanation: At constant pressure
\[\frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}} \Rightarrow \frac{300}{300}=\frac{V_{2}}{280}\] or V2 = 280 ml
8. For an ideal gas, correct relation is
a) \[\left[\frac{\delta E}{\delta V}\right]_{T}=0\]
b) \[\left[\frac{\delta E}{\delta T}\right]_{P}=0\]
c) \[\left[\frac{\delta E}{\delta T}\right]_{V}=0\]
d) All of these
Discussion
Explanation: \[\left[\frac{\delta E}{\delta V}\right]_{T}=0\] For ideal gas and positive for real gas.
9. The value of R in SI units is :
a) \[8.315*10^{7}erg K^{-1}mol^{-1}\]
b) \[8.315 JK^{-1}mol^{-1}\]
c) \[0.0815 litre atm K^{-1}mol^{-1}\]
d) \[2 calK^{-1}mol^{-1}\]
Discussion
Explanation: In SI unit value of R = \[8.315 JK^{-1}mol^{-1}\]
10. The compressibility factor for H2 and He is usually :
a) >1
b) =1
c) <1
d) Either of these
Discussion
Explanation: Since for H2 and He, PV > nRT and Z = \[\frac{PV}{nRT}\] . Hence Z is more than 1