Question

Raw milk sours in 4 hours at ${27}^{\circ }C,$ but in 40 hours in refrigerator at $7^{\circ }C.$ What is activation energy for souring of milk:

• A. 402.1 J/mol
• B. 30.2 J/mol
• C. 8.04 KJ/mol
• D. 80.4 KJ/mol

Answer 1

The correct option is B 30.2 J/mol

$K\alpha \frac{1}{t}$

$Log\frac{K_2}{K_1}=log\frac{t_1}{t_2}=\frac{E_a}{R}\left(\frac{T_2-T_1}{T_I\times T_2}\right)$

$Log\frac{40}{4}=\frac{E_a}{8.314}\left(\frac{20}{300\times 280}\right)$

So solving $E_a=30.2J/mol$