Some Basic Concepts of Chemistry

The sample with largest number of atoms is

• 1g O₂(g)

• 1g Ni(s)

• 1g B(s)

• 1g N₂(g)

An organic compound containing C, H and N gives the following on analysis : C = 40%, H = 13.33% and N = 46.67%. What would be its empirical formula?

• C₂H₇N

• C₂H₇N₂

• CH₄N

• CH₃N

The normality of 0.2M H₃PO₂ is

• 0.2 N

• 0.4 N

• 0.6 N

• 0.06 N

How many moles of O₂ can be obtained by electrolysis of 90 g H₂O?

• 5.0 mol

• 0.5 mol

• 2.5 mol

• 0.25 mol

An organic compound A contains 20% C, 46.66% N and 6.66% H. It gives NH₃ gas on heating with NaOH. A can be

• CH₃CONH₂

• C₆H₅CONH₂

• NH₂CONH₂

• CH₃NHCONH₂

Aqueous solutions of hydrogen sulphide and sulphur dioxide when mixed together, yield

• sulphur trioxide and water

• hydrogen and sulphurous acid

• sulphur and water

• hydrogen peroxide and sulphur

3 g of oxide of a metal is converted to chloride completely and it yielded 5 g of chloride. The equivalent weight of metal is

• 12

• 20

• 33.25

• 2.325

4.9 g of H₂SO₄ is present in 100 mL solution. The molarity and normality of the solution will be

• Molarity = 1M, Normality= 0.5N

• Molarity = 1M, Normality= 0.25N

• Molarity = 0.5M, Normality= 1N

• Molarity = 2M, Normality= 3N

0.0833 mole of a carbohydrate of empirical formula CH₂O contains 1.00 g of hydrogen. The molecular formula of the carbohydrate is.

• C₅H₁₀O₅

• C₃H₄O₃

• C₁₂H₂₂O₁₁

• C₆H₁₂O₆

When 50cm³ of 0.2N H₂SO₄ is mixed with 50 cm³ of 1N KOH, the heat liberated is

• 11.46 kJ

• 57.3 kJ

• 573 kJ

• 573 J