Question

The Half Life period of a first order reaction is 60 minutes what percentage will be left over after 240 minutes??
also explain​

Answer 1

First order reactions in chemistry are governed by a law that is similar to the familiar radioactive decay law of physics. In 240 minutes there are$\frac { 240}{60} = 4 \: half-lives$

$N→1\frac {N}{2} →2 \frac {N}{4} → 3 \frac{N}{8} → 4 \frac{N}{16}$

Percentage left after four half-lives =$\frac {(N/16)}{N} \times 100$

$= \frac {100}{16} %$

$= 6.25 %$

You can get the same result using the formula $N = N \frac{}{0} {e}^{ - kt}$

where k is the rate constant given by $t \frac{ }{ \frac{1}{2} } = \frac{ln2}{k}$

Answer 2

$\huge\mathfrak\blue{Answer:-}$

240 minutes implies 4 half lifes

let initial percentage be 100%

after 60 minutes it will become 50%

after 120 minutes it will become 25%

after 180 minutes it will become 12.5%

and finally after 240 minutes

= 6.25%

✨Half life means the percentage of that reaction will become half in that time ...