Question

The Arrhenius equation describes the effect of .............. on reaction rate.

• A. Pressure
• B. Temperature
• C. Volume
• D. Catalyst

Hint:

To quickly identify the role of temperature in reaction kinetics, remember the exponential form of the Arrhenius equation: even a small increase in $T$ causes a significant increase in rate.

Answer 1

The Correct Option is B

The Arrhenius equation gives a quantitative relationship between the rate constant of a chemical reaction and temperature. It is expressed as:
\[ k = A \cdot e^{\frac{-E_a}{RT}} \]
Where:
$k$ = rate constant of the reaction
$A$ = frequency factor (also known as the pre-exponential factor)
$E_a$ = activation energy of the reaction
$R$ = universal gas constant
$T$ = absolute temperature in Kelvin
This equation indicates that as the temperature increases, the exponential factor increases significantly, leading to a much faster rate constant $k$.
The Arrhenius equation is specifically used to describe the temperature dependence of reaction rates. While pressure and catalysts do affect reactions, they are not part of this equation’s focus. Catalysts work by lowering $E_a$, but the equation's variable of direct study is temperature.
Thus, the correct answer is: Temperature.