The rate of effusion of two gases A and B are in the ratio 1:2. If molar mass of A is 64 g/mol, molar mass of B is:
A. 256 g/mol
B. 128 g/mol
C. 32 g/mol
D. 16 g/mol
Answer: Option D
Solution (By JKExamLibrary)
Graham's law: r₁/r₂ = √(M₂/M₁). Given rA/rB = 1/2, so √(MB/MA) = 1/2. Squaring: MB/MA = 1/4 => MB = MA/4 = 64/4 = 16 g/mol. B is lighter and diffuses faster. Logical check: rate inversely proportional to square root of molar mass; if rate is double, mass is quarter. Answer is 16.
Explanation:
Baking powder is a mixture of sodium bicarbonate (baking soda) and a mild edible acid, usually tartaric acid. When moistened and heated, they react to release CO₂, causing dough to rise. Baking soda alone requires an external acidic ingredient. The acid ensures complete reaction and avoids a bitter taste.
Explanation:
Sodium carbonate is a salt of strong base (NaOH) and weak acid (H₂CO₃). On hydrolysis, it gives OH⁻ ions: CO₃²⁻ + H₂O ⇌ HCO₃⁻ + OH⁻, making the solution basic. pH ~11. It turns red litmus blue. It is used for softening hard water and in detergents. NaHCO₃ solution is also mildly basic. Salts of strong acid + strong base are neutral (NaCl). Salts of weak base + strong acid are acidic (NH₄Cl).
Explanation:
Chromatography separates components of a mixture based on their different affinities for stationary and mobile phases. Used for dyes, drugs, amino acids.
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