We can use the Arrhenius equation to solve this problem. The two-point form of the Arrhenius equation is:
\[ \ln{\frac{k_2}{k_1}} = \frac{E_a}{R} \left( \frac{1}{T_1} - \frac{1}{T_2} \right) \]
where:
$k_1$ and $k_2$ are the rate constants at temperatures $T_1$ and $T_2$, respectively.
$E_a$ is the activation energy.
R is the ideal gas constant.
Given: $k_1 = 0.04$ s$^{-1}$
$k_2 = 0.14$ s$^{-1}$
$T_1 = 500$ K
$T_2 = 700$ K
R = 8.31 J K$^{-1}$mol$^{-1}$
$\log 3.5 = 0.5441$ which means $\ln 3.5 = 2.303 \times 0.5441 = 1.253$
Plugging the values into the equation:
\(\ln{\frac{0.14}{0.04}} = \frac{E_a}{8.31} \left( \frac{1}{500} - \frac{1}{700} \right)\)
\(\ln{3.5} = \frac{E_a}{8.31} \left( \frac{700 - 500}{500 \times 700} \right)\)
\(1.253 = \frac{E_a}{8.31} \left( \frac{200}{350000} \right)\)
\(1.253 \times 8.31 \times 350000 = E_a\)
\(E_a = \frac{1.253 \times 8.31 \times 350000}{200}\)
\(E_a = 18219 J\)
The rate of a reaction:
A + B −→ product
is given below as a function of different initial concentrations of A and B.
Experiment | \([A]\) (mol L\(^{-1}\)) | \([B]\) (mol L\(^{-1}\)) | Initial Rate (mol L\(^{-1}\) min\(^{-1}\)) |
---|---|---|---|
1 | 0.01 | 0.01 | \(5 \times 10^{-3}\) |
2 | 0.02 | 0.01 | \(1 \times 10^{-2}\) |
3 | 0.01 | 0.02 | \(5 \times 10^{-3}\) |
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :