The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is (at. mass of Al = 27)

1. 180 kg

2. 270 kg

3. 540 kg

4. 90 kg

In the Haber process, 30 L of H₂ and 30 L of N₂ are allowed to react. If the reaction gives only 50% of the theoretically expected yield of NH₃, what will be the composition of the gaseous mixture at the end of the reaction?

1. 20 L ammonia, 10 L nitrogen, 30 L hydrogen

2. 10 L ammonia, 25 L nitrogen, 15 L hydrogen

3. 20 L ammonia, 20 L nitrogen, 20 L hydrogen

4. 20 L ammonia, 25 L nitrogen, 15 L hydrogen

What is the approximate number of atoms present in 4.25 grams of NH₃?

1. 4 x 10²³ 

2. 2 x 10²³ 

3. 1 x 10²³ 

4. 6 x 10²³ 

For the reaction:

4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(l)

If 1 mol of NH₃ is mixed with 1 mol of O₂ and the reaction proceeds to completion, which of the following statements is correct?

An element X occurs naturally as three isotopes with the following abundances:

²⁰⁰X = 90%, ¹⁹⁹X = 8%, and ²⁰²X = 2%.

What is the approximate average atomic mass of element X?

Calculate the vapour density of a volatile gas if 0.24 g of the gas produces 45 mL of vapour at NTP.
(Given that the density of hydrogen at STP is 0.08988 g L⁻¹).

1. 95.93

2. 59.93

3. 95.39

4. 69.93

A hydrated sodium sulphate salt, Na₂SO₄·nH₂O, loses 55% of its mass on heating to form anhydrous Na₂SO₄. What is the value of n?

12 g of Mg (atomic mass = 24) will react completely with an acid to yield:

1. One mole of H₂ 

2. A half mole of H₂

3. One mole of O₂

4. None of the above

The molality of a 15% (w/vol.) solution of H₂SO₄ of density 1.1g/cm³ is:

1. 1.2 mol/kg

2. 1.4 mol/kg

3. 1.8 mol/kg

4. 1.6 mol/kg

Which mode of expressing concentration is independent of temperature?

1. Molality

2. Percent by mass

3. Mole fraction

4. All of the above