If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

### Course: Physical Chemistry (Essentials) - Class 12>Unit 3

Lesson 3: Rate law and rate expressions

# Initial Rate method

You might need: Calculator

## Problem

Rate data was collected from $3$ separate experiments conducted under similar conditions, for the reaction,
$\begin{array}{r}\text{L}\left(\text{g}\right)+3\phantom{\rule{0.167em}{0ex}}\text{F}\left(\text{g}\right)\to \text{W}\left(\text{g}\right)\end{array}$,
The rate data so obtained in the experiments was,
$\text{Exp. No.}$$\left[\text{L}{\right]}_{0}$$\left[\text{F}{\right]}_{0}$$\text{Initial Rate}$
$1.$$0.2$$0.5$$1.4×{10}^{-3}$
$2.$$0.4$$0.5$$5.6×{10}^{-3}$
$3.$$0.4$$0.25$$2.8×{10}^{-3}$
The initial concentrations of reactants, $\left[\text{L}{\right]}_{0}$ and $\left[\text{F}{\right]}_{0}$ are taken in ${\text{mol L}}^{-1}$ and the value of initial rate ($\text{R}$) is reported in ${\text{mol L}}^{-1}\phantom{\rule{0.167em}{0ex}}{\text{s}}^{-1}$.
Which of the following depicts the unit of rate constant ($\text{k}$) for this reaction?