The activation energy of a chemical reaction can be determined by:

$A$ sample of milk splits after $60 \; min.$ at $300 \; K$ and after $40 \; min.$ at $400 \; K$ when the population of $Lactobacillus \; acidophilus$ in it doubles. The activation energy (in $kJ / mol$) for this process is closest to ............. $kJ / mol$.
(Given: $R = 8.3 \; J \; mol^{-1} \; K^{-1}$,$\ln(1.5) = 0.405$)

The Arrhenius plots of two reactions,$I$ and $II$ are shown graphically. The graph suggests that

Two reactions of the same order have equal Pre-exponential factors but their activation energies differ by $24.9 \ kJ/mol$. Calculate the ratio between the rate constants $\left( \frac{K_2}{K_1} \right)$ of these reactions at $27 \ ^\circ C$.

The half-life of a first order reaction varies with temperature according to

The rate of a chemical reaction doubles with every $10^{\circ}C$ rise in temperature. If the reaction is carried out in the vicinity of $22^{\circ}C$,the activation energy of the reaction is (Given $R = 8.3 \ J \ K^{-1} \ mol^{-1}$,$\ln 2 = 0.69$ and $\ln 3 = 1.1$)