Solution
Step 1: Analyzing the reactions with Concentrated H2SO4
NaBr conc. H₂SO₄ Br₂ (Reddish-brown vapour evolves) NaNO₃ conc. H₂SO₄ NO₂ (Brown vapour evolves) KI conc. H₂SO₄ I₂ (Violet vapour evolves) CaF₂ conc. H₂SO₄ HF (Colorless vapour evolves)
Thus, CaF₂ does not evolve colored vapours.
Step 2: Calculating Molar Mass
Molar mass of CaF₂: Ca = 40
F₂ = 2 × 19 = 38 Molar mass = 40 + 38 = 78 g/molChapter Mix
Class 12 Chemistry: Salt Analysis