Question

In Arrhenius equation, $k = Ae ^{\frac{E_{a}}{R T}}, A$ 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)

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