Question

The rate constant of a certain first order reaction is 3.12 x 10-3. Min-!: (a) how many minutes does it take for the reactant concentration to drop to 0.02 m if the initial concentration of the reactant is 0.045 m

Answer 1

Answer:

Given, K=6.8×10

−4

s

−1

; [A

o

]=0.04 M;

t=20 min=20×60=1200 sec

K=

t

2.303

log

[A

t

]

1

[A]

o

⟹6.8×10

−4

=

1200

2.303

log

10

(

[A

t

]

0.04

)

⟹Antiog(0.3545)=

[A

t

]

0.04

⟹2.261=

[A

t

]

0.04

⟹[A

t

]=0.0177 M