6.02 x 10²⁰ molecules of urea are present in 100 mL of its solution. The concentration of solution is

• 0.02 M

• 0.01 M

• 0.001 M

• 0.1 M

The normality of 30 volume H₂O₂ is:

• 2.678 N

• 5.336 N

• 8.034 N

• 6.685 N

An organic compound made of C, H and N contains 20% nitrogen. Its molecular weight is

• 70

• 140

• 100

• 65

In the reaction of sodium thiosulphate with I₂ in aqueous medium, the equivalent weight of sodium thiosulphate is equal to

• molar mass of sodium thiosulphate

• the average of molar masses of Na₂S₂O₃ and I₂

• half the molar mass of sodium thiosulphate

• molar mass of sodium thiosulphate × 2

The molarity of a NaOH solution by dissolving 4 g of it in 250 mL water is

• 0.4 M

• 0.8 M

• 0.2 M

• 0.1 M

If it is assumed that ${}_{92}{}^{235}\mathrm{U}$ decays only by emitting $\mathrm{\alpha }$-and ($\mathrm{\beta }$-particles, the possible product of the decay is

• ${}_{89}{}^{225}\mathrm{Ac}$

• ${}_{89}^{227}\mathrm{Ac}$

• ${}_{89}{}^{230}\mathrm{Ac}$

• ${}_{89}{}^{231}\mathrm{Ac}$

Sodium nitrate on reduction with Zn in presence of NaOH solution produces NH₃. Mass of sodium nitrate absorbing 1 mole of electron will be

• 7.750

• 10.625

• 8.000

• 9.875

In transforming 0.01 mole of PbS to PbSO₄, the volume of '10 volume' H₂O₂ required will be

• 11.2 mL

• 22.4 mL

• 33.6 mL

• 44.8 mL

An unknown element forms an oxide.What will be the equivalent weight of the element if the oxygen content is 20% by weight?

• 16

• 32

• 8

• 64

2 N HCl solution will have same molar concentration as a

• 4.0 N H₂SO₄

• 0.5 N H₂SO₄

• 1 N H₂SO₄

• 2 N H₂SO₄