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

• 90

• 180

• 80

• 100

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

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

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

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

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

MnO₂ + HCl $\stackrel{∆}{\to }$ A (g)

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

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

A liquid can exist only

• between triple and critical points

• at any temperature above melting point

• between melting and critical points

• between boiling and melting points

HCl gas is covalent and NaCl is an ionic compound. This is because

• sodium is highly electropositrve

• hydrogen is a non-metal

• HCl is a gas

• electronegativity difference between H and Cl is less than 2.1