31. When a gas is heated from 298K to 323K at a constant pressure of 1 atm its volume is
A. Increases from V to 1.8 V
B. Increases from V to 1.08 V
C. Increases from V to 1.5 V
D. Increases from V to 2 V
Answer : Option B
Explanation :
According to Charles’ law
\(\frac{V_{1}}{T_{1}}=\frac{V_{2}}{T_{2}}\)
\(\frac{V_{1}}{298}=\frac{V_{2}}{323}\)
\(\therefore V_{2}=\frac{323}{298}V_{1}\)
\(=1.08V_{1}\)
32. At \(20^{\circ}C\) and 760 torr, the sample of air contains 20% \(O_{2}\) & 80% \(N_{2}\) gaseous mixture, find the density of the air (Molarmass \(O_{2}\) = 32 g/mol , \(N_{2}\) = 28 g/mole R =0.082 \(liter\ mole^{-1}K^{-1}\))
A. 1.918 \(gL^{-1}\)
B. 2.198 \(gL^{-1}\)
C. 1.198 \(gL^{-1}\)
D. 1.394 \(gL^{-1}\)
Answer : Option C
33. The ratio of velocities of diffusion of gas A and B is 1 : 4, if the ratio of their masses in a mixture is 2:3, calculate the ratio of their mole fractions (BIT 1990)
34. Under same conditions of temperature and pressure the volumes of 14g \(N_{2}\) and 36g of \(O_{3}\) are related as :
A. \(2V_{N_{2}}=3V_{O_{3}}\)
B. \(3V_{N_{2}}=2V_{O_{3}}\)
C. \(3V_{N_{2}}=4V_{O_{3}}\)
D. \(4V_{N_{2}}=3V_{O_{3}}\)
Answer : Option B
35. Equal masses of Hydrogen and oxygen gases are placed in a closed container, at a pressure of 3.4 atm. The contribution of hydrogen gas to the total pressure is
36. The kinetic energy of 4.0 moles of \(N_{2}\) gas at \(127^{\circ}C\) is \(\left ( R=2\ cal\ mole^{-1}K^{-1} \right )\)
37. The critical temperature of \(H_{2}O\) is higher than \(CO_{2}\) because (IIT 1997)
A. fewer electrons than \(CO_{2}\)
B. It contains 2- covalent bonds
C. Molecular shape is V- shape
D. dipole moment of \(H_{2}O\)
Answer : Option D
39. A 10 L cylinder of nitrogen at 4.0 atm pressure and \(27^{\circ}C^{-}\) developed a leak. When the leak was repaired 2.36 atm of nitrogen remained in the cylinder at \(27^{\circ}C\). How many grams of nitrogen escaped?
40. Calculate percentage of \(NO_{2}\) by weight in \(N_{2}O_{4}\) which has vapour density of 36.