DP Chemistry Questionbank

Which is true of an Arrhenius plot of $\ln k$ (y-axis) against $\frac{1}{T}$?

A.     The graph goes through the origin.

B.     The activation energy can be determined from the gradient.

C.     The intercept on the x-axis is the activation energy.

D.     The intercept on the y-axis is the frequency factor, A.

The Arrhenius equation, $k=A{e}^{-\frac{Ea}{RT}}$, gives the relationship between the rate constant and temperature.

State how temperature affects activation energy.

Describe how the activation energy of this reaction could be determined.

The rate constant for a reaction doubles when the temperature is increased from 25.0 °C to 35 °C.

Calculate the activation energy, E_a, in kJ mol⁻¹ for the reaction using section 1 and 2 of the data booklet.

What is the intercept on the y-axis when a graph of lnk is plotted against $\frac{1}{T}$ on the x-axis?

$\ln k=-\frac{E_a}{RT}+\ln A$

A.  lnA

B.  $-\frac{E_{\mathrm{a}}}{R}$

C.  $-\frac{R}{E_{\mathrm{a}}}$

D.   $E_{\mathrm{a}}$