Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

At 300 K, a gaseous reaction A → B + C was found to follow first order kinetics. Starting with pure A, the total pressure at the end of 20 min was 100 mm of Hg. The total pressure after the completion of the reaction is 180mm of Hg. The partial pressure of A (in mm of Hg) is

312.
2 moles of N₂O₄ (g) is kept in a closed container at 298 K and under 1 atm pressure. It is heated to 596 K when 20% by mass of N₂O₄ (g) decomposes to NO₂. The resulting pressure is

1.2 atm

4.8 atm

2.8 atm

2.4 atm

2.4 atm

$\underset{= 1.6 mol}{\underset{= 147.2}{\underset{2 \times 92 - 2 \times 92 \times 0.2}{\underset{2 mol}{\underset{1 mol}{N_{2} O_{4}}}}}} ⇌ \underset{= 0.8 mol}{\underset{= 73.6}{\underset{2 \times 2 \times 92 \times 0.2}{\underset{2 \times 92 g}{\underset{92 gm}{2 {NO}_{2}}}}}} \underset{}{\underset{}{\underset{At equilibrium}{\underset{Initially}{\underset{}{}}}}}$

Total moles = 1.6 + 0.8 = 2.4

At constant volume,

$\frac{p_{1}}{n_{1} T_{1}} = \frac{p_{2}}{n_{2} T_{2}} \frac{1}{2 \times 298} = \frac{p_{2}}{2.4 \times 596} p_{2} = \frac{2.4 \times 596}{596} = 2.4 atm$

313.

The mass of a non-volatile solute of molar mass 40 g mol^-1 that should be dissolved in 114 g of octane to lower its vapour pressure by 20% is

11.4 gm
9.8 gm
12.8 gm
10 gm

314.

20 mL of methane is completely burnt using 50 mL of oxygen. The volume of the gas left after cooling to room temperature is

40 mL
60 mL
30 mL
80 mL

315.

The statement that is not correct is

A furnace filled with haemalite is used to convert cast iron to wrought iron
Collectors enhance the wettability of mineral particles during froth flotation
In vapour phase refining, metal should form a volatile compound
Copper from its low grade ores is extracted by hydrometallurgy

316.

Density of carbon monoxide is maximum at

2 atm and 600 K
0.5 atm and 273 K
6 atm and 1092 K
4 atm and 500 K

317.

MnO₂ + HCl $\overset{∆}{\to}$ A (g)

A (g) + F₂ (excess) $\overset{573 K}{\to}$ B (g)

B (l) + U (s) → C (g) + D (g)

The gases A, B, C and D are respectively

Cl₂, ClF, UF₆, ClF₃
Cl₂, ClF₃, UF₆, ClF
O₂, OF₂, U₂O₃, O₂F₂
O₂, O₂F₂, U₂O₃, OF₂

318.

The statement that is not correct is

Compressiblity factor measures the deviation of real gas from ideal behaviour
Van der Waals constant 'a' measures extent of intermolecular attractive forces for real gases
Cnlical temperature is the lowest temperature at which liquefaction of a gas first occurs
Boyle point depends on the nature of real gas