Question

A first order reaction has a rate constant 1.15×10^-3 S^-1. How long will 5g of the reactant take to reduce to 3g.

Answer 1

Answer:

thanks for free points please don't mind

Answer 2

Answer:

• $444 \:seconds$

Explanation:

Given

• Initial amount $[R]_{0} = 5g$
• Final concentration $[R] = 3g$
• Rate constant $(k) = 1.15 \times 10^{-3} s^{-1}$

Formula:

$\boxed{ t = \frac{2.303}{k} log\frac{[R]_{0}}{[R]}}$

Putting the values

$\implies\:\:\:t = \frac{2.303}{1.15\times10^{-3}}log\frac{5}{3}second$

$\implies\:\:\:t = \frac{2.303}{1.15\times10^{-3}}\times 0.2219 \: seconds$

$\implies\:\:\:t = 444.196 \:second$

$\implies\:\:\:t =444 \:seconds\: (approx)$