Question

In Arrhenius equation, $k=A{e}^{\frac{E_a}{RT}},A$ may not be termed as rate constant

• A. When $100\%$ reactant will convert into the product
• B. When the temperature becomes infinite
• C. When the fraction of molecule crossing over the energy barrier becomes unity
• D. At very low temperature

Answer 1

Answer: (D)

$K=A{e}^{\frac{-E_a}{RT}}$
1. $100\%$ reactant will convert into the product i.e., $\left[E_a=0\right]$
So, $K=A{e}^{\circ }\to [K=A]$
2. $T=8$
$K=A{e}^{\frac{-E_a}{R\times 8}}$
$K=A{e}^{\circ }\to (K=A)$
3. Fraction of molecule crossing over the energy barrier becomes unity $(100\%)\to \left(E_a=0\right)$.
So, again $(K=A)$
4. At very low temperature $K=A{e}^{-E_3/RT}$
$K\ne A$