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 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

A sample of pure Cu (3.18g ) heated in a stream of oxygen for some time gains in mass with the formation of black oxide of copper (CuO). The final mass is 3.92 g. The percent of copper remains unoxidised is-

1.$\approx$6.5 

2.$\approx$6.9

3. $\approx$7.6

4. $\approx$7.9

One mole of a mixture of CO and CO₂ requires exactly 20g of NaOH in solution for the complete conversion of all the CO₂ into Na₂CO₃. How much NaOH would it require for conversion into Na₂CO₃, if the mixture (one mole) is completely oxidised to CO₂?

1. 60g

2. 80g

3. 40g

4. 20g

Versene, a chelating agent having chemical formula C₂H₄N₂(C₂H₂O₂Na)₄. If each mole of this compound could bind 1 mole of Ca²⁺, then the rating of pure versene expressed as mg of CaCO₃ bound per g of chelating agent is:

1. 100 mg

2. 163 mg

3. 200 mg

4. 263 mg

When 100 mL of PH₃ is decomposed, it produces phosphorus and hydrogen. The change in volume is:

A sample of CaCO₃ is 50% pure. On heating 1.12 litres of CO₂ (at STP) is obtained. The weight of residues left (assuming non-volatile impurity) is:

(Ca = 40, C= 12, O=16)