Reaction Yield Lesson 6

reactants products ⇌ ⇌ The Yield of a Reaction The yield is the amount of products. Low yield High yield reactants products ⇌ reactants products ⇌

The Haber Process is used to make ammonia 4 2 N2(g) + 3H2(g) ⇌ 2NH3(g) + energy To ensure a high yield low temperature high pressure remove NH3 add N2 and H2

The Haber Process is used to make ammonia 4 2 N2(g) + 3H2(g) ⇌ 2NH3(g) + energy To ensure a high rate high temperature- 600 0C high pressure- 20000 Kpa add N2 and H2 add catalysts Os and Ur

1 2 N2O4(g) ⇋ 2NO2(g) + 59 KJ Increasing the yield low temperature low pressure remove NO2 add N2O4

1 2 N2O4(g) ⇋ 2NO2(g) + 59 KJ Increasing the rate high temperature high pressure add N2O4 add a catalyst

Know the difference between Rate and Yield! Rate is how fast you get to equilibrium. Yield is the amount of product relative to reactants at equilibrium.

1. What conditions will produce the greatest yield? P2O4(g) ⇋ 2PO2(g) ∆H = -28 kJ A. high temperature & high pressure C. high temperature & low pressure D. low temperature & high pressure + 28KJ B. low temperature & low pressure

2. What conditions will produce the greatest rate? Zn(s) + 2HCl(aq) → H2(g) + ZnCl2(aq) A. high Zn surface area, low [HCl], low temperature B. low Zn surface area, high [HCl], high temperature D. high Zn surface area, high [HCl], low temperature C. high Zn surface area, high [HCl], high temperature

3. What increases the rate? Zn(s) + 2HCl(aq) → H2(g) + ZnCl2(aq)   A. removing H2 B. removing ZnCl2(aq) C. lowering pressure D. adding HCl

Graphing Equilibrium   N2O4(g) ⇋ 2NO2(g) + 59 KJ 1. Adding N2O4 [N2O4] [NO2] x 2x

Graphing Equilibrium   N2O4(g) ⇋ 2NO2(g) + 59 KJ 2. Removing NO2 [N2O4] [NO2] x 2x

Graphing Equilibrium   N2O4(g) ⇋ 2NO2(g) + 59 KJ 3. Increase Temperature [N2O4] [NO2] x 2x

Graphing Equilibrium   N2O4(g) ⇋ 2NO2(g) + 59 KJ 3. Decrease Volume- all concentrations + pressure goes up! [N2O4] [NO2] 2x x