Question

The rate of a reaction decreases with increase in _________________.

• A. the concentration of the reactants
• B. temperature of the reaction
• C. time of the reaction
• D. with all the three

Answer 1

The correct option is C time of the reaction

Rate law state that;

$\alpha A\to Product$

$-r_A=K{C}_A^{\alpha }$, Where K is function of tempreature as,

$K=K_O{e}^{-\frac{E_a}{RT}}$

i.e

$-r_A=K_{0}e-\frac{E_a}{RT}{C}_A^{\alpha }$

$-r_A=$Rate of decomposition of A

$E_a=$Activation Energy of Reaction

$R=$Gas Constant

$T=$Temperature

$\alpha =$rate of reaction

$C_A\uparrow \Rightarrow (-r_a)\uparrow \left(X\right)$

$T\uparrow \Rightarrow K\uparrow \Rightarrow (-r_a)\uparrow$

we, know as times passes concentration of reactant decrease. So, from rate law rate of reaction decreases.