Rates Solution Page 3

  1. Which of the following is the fastest reaction ad which is the slowest at the same temperature? Give your reasons for your choice.

(1) H2 + I2 → 2HI Ea = 167.2 kJ/mol

(2) 2HI → H2 + I2 Ea = 183.92 kJ/mol

(3) NO + O3 → NO2 + O2 Ea = 10.45 kJ/mol

Equation 2 has the highest energy of activation so should be the slowest

Equation 3 has the lowest energy of activation so should be the fastest.

  1. For the reaction A + B = C + D
rates 06

 

a) For the unanalyzed reaction, what is the value of energy in kJ/mol of

a. The activation energy 80 kJ – 10 kJ = 70 kJ

b. The heat of reaction or enthalpy change 25 kJ – 10 kJ = +15 kJ Endothermic reaction

c. The potential energy of the activated complex 80 kJ

d. The activation energy for the reverse reaction 80kJ – 25kJ = 55kJ

b) For the catalyzed reaction, what is the value of energy in kJ/mol of:

a. The potential energy of the activated complex 65 kJ

b. The heat or reaction 25 kJ – 10 kJ = +15 kJ Endothermic reaction Does not change

 

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