Question

A Ist order reaction has a rate constant is 1.15 ×10^-1 S-^1.
How long will 5 gram of this
reactant take to reduce to 3 gram.

Answer 1

Answer:

4.40sec

Explanation:

see attached file

Answer 2

Answer:

Given that

Initial quantity, [R]⁰= 5 g

Final quantity, [R] = 3 g Formula of 1st order reaction,

Rate constant, k = 1.15 x 10-3 s-1

We know that

2.303 [R] t = -log k [R]

-3 1.15 x 107 2.303 1.15 x 10 -log (5) 3 -(log 5 - log 3) =

2.303

t =

2.303

1.15 x 10-3

=

-(0.6990-0.4771)

2.303 x 0.2219

1.15 x 10-3 2.303 x 0.2219 × 1000

1.15

444 sec.