Experimental measurements of rxn rates

Volume Changes of a Gas eudiometer Volume (mL) Time (s) Zn (s) + 2HCl (aq) → H 2(g) + ZnCl 2(aq)

Rate in mL/s H 2 Rate in mol/min for H 2 Rate in g/h for HCl

(time sec) Volume (mL) Rise: = 4.3 Run: 75-0 = 75 Slope= Rise/Run= 4.3/75= mL/s

Changes in Pressure (constant volume or sealed container) if more moles of gas (coefficient) in products, pressure will go up Zn(s) + 2HCl(aq)  H 2 (g) + ZnCl 2 (aq) ____m.o.g. ____ m.o.g. If more MOG in reactants, pressure will __________________________ rate = ∆ pressure(constant volume) ∆ time

If equal MOG, pressure will not change: NO 2 (g) + CO(g)  CO 2 (g) + NO(g) 2 m.o.g. 2 m.o.g.

Mass of an open container {Changes in Mass} Mass (g) Time (s) CaCO 3(s) + 2HCl (aq) → CO 2(g) + CaCl 2(aq) + H 2 O (l)

1. Calculate the rate in units of grams/s for CO 2 2.Calculate the rate in grams/h for CaCO 3

Hebden p 5 exercises: Page 11 questions