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

2. 1.4

3. 1.8

4. 1.6

Which mode of expressing concentration is independent of temperature?

1. Molality

2. Percent by mass

3. Mole fraction

4. All of the above 

The product of atomic mass and specific heat of metal is approximately 6.4. This was given by:

1. Dalton's law

2. Avogadro's law

3. Newton's law

4. Dulong Petit's law

A metal M forms a compound M₂HPO₄. The formula of the metal sulphate is:

1. M₂SO₄ 

2. MSO₄

3. M(SO₄${)}_2$

4. M₂(SO₄)₃

A partially dried clay mineral contains 8% water. The original sample contained 12% water and 45% silica. The percentage of silica  in the partially dried sample is nearly:

One litre N₂, 7/8 litre O₂ and 1 litre CO are taken in a mixture under indentical conditions of P and T. The amount of gases present in mixture is given by:

1. ${\mathrm{\omega }}_{{\mathrm{N}}_2}={\mathrm{\omega }}_{{\mathrm{O}}_2}>{\mathrm{\omega }}_{\mathrm{CO}}$ 

2. ${\mathrm{\omega }}_{{\mathrm{N}}_2}={\mathrm{\omega }}_{\mathrm{CO}}>{\mathrm{\omega }}_{{\mathrm{O}}_2}$ 

3. ${\mathrm{\omega }}_{{\mathrm{N}}_2}={\mathrm{\omega }}_{{\mathrm{O}}_2}={\mathrm{\omega }}_{\mathrm{CO}}$

4. ${\mathrm{\omega }}_{\mathrm{CO}}>{\mathrm{\omega }}_{{\mathrm{N}}_2}>{\mathrm{\omega }}_{{\mathrm{O}}_2}$

Equal volumes of 0.1 M AgNO₃ and 0.2 M NaCl are mixed. The concentration of N${\mathrm{O}}_3^{-}$ ions in the mixture will be:

A solution contains Na₂CO₃ and NaHCO₃. 10 mL of the solution required 2.5 mL of 0.1 M H₂SO₄ for neutralisation using phenolphthalein as indicator. Methyl orange is then added when a further 2.5 mL of 0.2 M H₂SO₄ was required. The amount of Na₂CO₃ and NaHCO₃ in 1 litre of the solution is:

1. 5.3g and 4.2g

2. 3.3g and 6.2g

3. 4.2g and 5.3g

4. 6.2g and 3.3g

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