Grignard reagent RMgBr (P) reacts with water and forms a gas (Q). One gram of Q occupies $$1.4 dm^{3}$$ at STP.(P) on reaction with dry ice in dry ether followed by $$H_{3}O^{+}$$ fonns a compound (Z). 0.1 mole of(Z) will weigh ____ g. (Nearest integer)

We need to find the mass of 0.1 mole of compound Z.

Identify gas Q.

RMgBr + H₂O → RH + Mg(OH)Br

Gas Q = RH (hydrocarbon)

At STP: 1 g of Q occupies 1.4 dm³ = 1.4 L

Molar volume at STP = 22.4 L/mol

Molar mass of Q = $$\frac{22.4}{1.4} \times 1 = 16$$ g/mol

So Q = CH₄ (methane, molar mass = 16), which means R = CH₃ (methyl group).

Identify compound Z.

CH₃MgBr + CO₂ (dry ice) → CH₃COOMgBr

CH₃COOMgBr + H₃O⁺ → CH₃COOH (acetic acid)

So Z = CH₃COOH, molar mass = 60 g/mol.

Find mass of 0.1 mole of Z.

Mass = 0.1 × 60 = 6 g

Therefore, 0.1 mole of Z weighs 6 g.