How much oxygen gas (O₂) at standard temperature (0°C) and pressure (1 atm) is required to completely combust 1 liter of propane gas (C₃H₈) under the same conditions?

1. 7L 
2. 6L
3. 5L
4. 10L

1 g of magnesium is burnt with 0.56g of oxygen in a closed vessel. The left-out reactant and its quantity are

(At. weight of Mg = 24, O=16)

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 reaction, 4NH₃(g)+ 5O₂(g) $\to$4NO(g) +6H₂O(l)

When 1 mole of ammonia and 1 mole of O₂  reacts to completion, then:

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