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?

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:

When 22.4L of H₂(g) is mixed with 11.2L of Cl₂(g) each at STP, the moles of HCl(g) formed is equal to 

1. 1 mole of HCl(g)

2. 2 moles of HCl(g)

3. 0.5 mole of HCl(g)

4. 1.5 moles of  HCl(g)

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 

The total number of valence electrons in 4.2g of ${\mathrm{N}}_3^{-}$ ion is (N_A is the Avogadro's number)

1. 2.1N_A 

2. 4.2N_A 

3. 1.6N_A 

4. 3.2N_A 

In the Haber process, 30 L of dihydrogen and 30 L of dinitrogen were taken for the reaction, which yielded only 50% of the expected product. The composition of the gaseous mixture under the said conditions at the end is: 

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

2. 20 L ammonia, 25 L nitrogen, 15 L hydrogen

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

4. 10 L ammonia, 25 L nitrogen, 15 L hydrogen

Percentage of Se in peroxidase anhydrase enzyme is 0.5% by weight (at. weight = 78.4), then minimum molecular weight of peroxidase anhydrase enzyme is

1. 1.568 x 10³ 

2. 15.68

3. 2.168 x 10⁴ 

4. 1.568 x 10⁴ 

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