Rates, Orders + Arrhenius

Question 1

What are the units of ROR?

Answer 1

• mol dm^-3s^-1

Question 2

What is the rate equation for the reaction:
A(aq) + B(aq) —-> C(aq) + D(g)?

Answer 2

Rate = k[A]^m[B]^n
- m + n = orders wrt each reactant

Question 3

What does a zero order of reaction wrt a chemical mean?

Answer 3

• changing conc has no effect on ROR
• so not included in rate equation

Question 4

What does a 1st order of reaction wrt a chemical mean?

Answer 4

• conc of chemical is directly proportional to ROR (doubling conc = doubles rate)
• chemical is included in rate equation

Question 5

What does a 2nd order of reaction wrt a chemical mean?

Answer 5

• rate is directly proportional to square of conc (doubling conc inc ROR by x4)
• included in rate equation (as a squared term)

Question 6

What is the overall order of reaction?

Answer 6

• sum of all powers of reactant in rate equation