Question

The rate constant for a certain reaction is k = 6.30×10−3 s−1 . If the initial reactant concentration was 0.500 M, what will the concentration be after 19.0 minutes? Express your answer with the appropriate units.

Answer 1

Answer: 0.059M

Explanation: time.

t = 19minutes

t = 19 × 60 s

t = 140s

k = n/delta t

(where n is the ratio of change in concentration while delta t is the change in time)

k = n/dt = 6.30×10−3 s−1

6.30×10−3 s−1 = dc/140s

n = 6.30×10−3 s−1 × 140s

n = 882 ×10−3

= 0.882

Concentration of reactant used in forming a product in the reaction after 19 minutes =

n × concentration

0.882 × 0.5 = 0.441M

Reactant concentration

= (0.5 - 0.441)M

= 0.059M