alleryWhich of these solutions will boil at the highest temperature at 1 atm?
A0.1 m glucose
B0.1 m Na₂SO₄
C0.1 m NaCl
DPure water
Answer & Solution
Correct answer: B. 0.1 m Na₂SO₄
1. Boiling point elevation ΔT_b = K_b × m × i (with i the van't Hoff factor).
2. For glucose i = 1; for NaCl i ≈ 2; for Na₂SO₄ i ≈ 3 (dissociates into 2 Na⁺ + SO₄²⁻).
3. So Na₂SO₄ gives the largest ΔT_b at the same molality.
4. Higher elevation means a higher observed boiling point at 1 atm.
_Source: syllabus Chemistry, Unit 1 "Solutions", §1.6_
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