Problem

The following data were collected for the reaction

2\text{H}_2\text{O}_2(\text{aq}) \rightarrow 2\text{H}_2\text{O}(\text{l}) + \text{O}_2(\text{g})

390^\circ\text{C}

$[\text{H}_2\text{O}_2] / \text{mol dm}^{-3}$	Time / s	$[\text{H}_2\text{O}_2] / \text{mol dm}^{-3}$	Time / s
0.200	0	0.070	120
0.153	20	0.063	140
0.124	40	0.058	160
0.104	60	0.053	180
0.090	80	0.049	200
0.079	100

Draw a graph of concentration against time and determine the reaction rate after 60 s and after 120 s.