Question

A first-order reaction is $50$% completed in $20$ minutes at ${27}^0$ C and in $5min$ at ${47}^0$C. The energy of activation of the reaction is :

• A. $43.85kJ/mol$
• B. $55.33kJ/mol$
• C. $11.97kJ/mol$
• D. $6.65kJ/mol$

Answer 1

Answer: (B)

$55.33kJ/mol$

$t_1{k}_1=t_2{k}_{2}20\ast k_1=5\ast k_2\frac{k_1}{k_2}=4NowArrheniusequationlo{g}_{10}\left(\frac{k_2}{k_1}\right)=\frac{E_a}{2.30\ast R}\left(\frac{T_2-T_1}{T_1.T_2}\right)lo{g}_{10}\left(4\right)=\frac{E_a}{8.314\ast 2.3}\left(\frac{20}{300\ast 320}\right)E_a=55.332kJ/mole$