The number of water molecules are maximum in:

1.	18 molecules of water	2.	1.8 g of water
3.	18 g of water	4.	18 moles of water

A mixture of gases contains H₂ and O₂ gases in the ratio of 1 : 4 (w/w). The molar ratio of the two gases in the mixture will be:

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

1. 1 mol of HCl(g)
2. 2 mol of HCl(g)
3. 0.5 mol of HCl(g)
4. 1.5 mol of HCl(g)

1.0 g of magnesium is burnt with 0.56 g O₂ in a closed vessel. Which reactant is left in excess and by how much? (At. wt. Mg = 24; O = 16)

Mole fraction of solute in a 1.00 molal aqueous solution is:
1.  0.0177
2.  0.0344
3.  1.770
4.  0.1770

25.3 g of sodium carbonate, Na₂CO₃, is dissolved in enough water to make 250 mL of a solution. If sodium carbonate completely dissociates, the molar concentrations of sodium ion, Na⁺ and carbonate ion, $C{O}_3^{2-}$are respectively:
(molar mass of Na₂CO₃ = 106g mol^-1)

1. 0.955 M and 1.910 M
2. 1.910 M and 0.955 M
3. 1.90 M and 1.910 M
4. 0.477 M and 0.477 M

The number of atoms in 0.1 mole of a triatomic gas is (N_A= 6.02 x 10²³ mol^-1):

1. $6.026\times {10}^{22}$

2. $1.806\times {10}^{23}$

3. $3.600\times {10}^{23}$

4. $1.800\times {10}^{22}$

10 g of hydrogen and 64 of oxygen were filled in a steel vessel and exploded. The amount of water produced in this reaction will be:

1. 2 mol

2. 3 mol

3. 4 mol

4. 1 mol