The volume of 2 N H₂SO₄ solution is 0.1 dm³. The volume of its decinormal solution (in dm³) will be

• 0.1

• 0.2

• 2

• 1.7

An element _xA^y emits 5 α and 4β particles to give ₈₂B²⁰⁷. The number of protons and neutrons in A are respectively

• 88, 227

• 88, 139

• 82, 227

• 84, 139

The degree of dissociation of a 0.01 M weak acid is 10^-3. Its pOH is

• 5

• 3

• 9

• 11

0.1 M solution of which of the following has almost unity degree of dissociation ?

• Ammonium chloride

• Potassium chloride

• Sodium acetate

• All of the above

5.

The percentage (by weight) of sodium hydroxide in a 1.25 molal NaOH solution is

• 4.76%

• 1.25%

• 5%

• 40%

If 20 mL of an acidic solution of pH 3 is diluted to 100 mL, the H⁺ ion concentration will be

• 1 × 10^-3 M

• 2 × 10^-3 M

• 2 × 10^-4 M

• 0.02 × 10^-4 M 

At the same conditions of pressure, volume and temperature, work done is maximum for which gas if all gases have equal masses ?

• NH₃

• N₂

• Cl₂

• H₂S

16 g of oxygen gas expands isothermally and reversibly at 300 K from 10 dm³ to 100 dm³. The work done is (in J)

• zero

• - 2875 J

• + 2875 J

• infinite

The calculated mass of ₂₀Ca⁴⁰ is 40.328 u. It releases 306.3 MeV energy in a nuclear process. Its isotopic mass is

• 39.998

• 40.6570

• 0.3290

• 2.85 × 10⁴

The maximum number of unpaired electrons is present in

• Fe

• Cu

• Co

• Ni