Depression of freezing pointहिमांक का अवनमनDepression of freezing point

NCERT Fig 1.8 · Class 12 Chemistry · Chapter 1 · interactive diagram

Parts and what they mean

• Vapour pressure of frozen (solid) solvent (जमे (ठोस) विलायक का वाष्प दाब) — Only the solvent freezes out; this curve is the same for both.
• Vapour pressure of liquid solvent (द्रव विलायक का वाष्प दाब) — Meets the solid curve at Tf⁰ — the freezing point of pure solvent.
• Vapour pressure of solution (विलयन का वाष्प दाब) — Lower than the liquid solvent’s, so it meets the solid curve at a LOWER temperature Tf.
• Tf⁰ — freezing point of pure solvent (Tf⁰ — शुद्ध विलायक का हिमांक) — Solid and liquid have equal vapour pressure here.
• Tf — freezing point of solution (Tf — विलयन का हिमांक) — Solution’s vapour pressure equals the solid solvent’s here.
• ΔTf = Tf⁰ − Tf = Kf·m (ΔTf = Tf⁰ − Tf = Kf·m) — Depression of freezing point; Kf (water) = 1.86 K kg mol⁻¹.

Original diagram drawn by Simple Learning Hub, based on NCERT Fig 1.8. Report a mistake