# The rate of chemical equation is equal to slope of graph with ones labelled

$\begin{array}{1 1}(a)\;x-axis:time,y-axis:rate\\(b)\;x-axis:mass,y-axis:time\\(c)\;x-axis:Volume\;of\;gas,y-axis:time\\(d)\;x-axis:time,y-axis:concentration\end{array}$

$rate=\large\frac{d[c]}{dt}$
$d[c]\rightarrow$ concentration
$dt\rightarrow$ time
Hence (d) is the correct answer.