Question

According to law of mass action rate of a chemical reaction is proportional to :

• A. concentration of reactants
• B. molar concentration of reactants
• C. concentration of products
• D. molar concentration of products

Answer 1

Answer: (B)

Guldberg and Waage (1864) suggested relationship between rate of reaction and the concentration of the reacting species known as law of mass action.
According to this "at constant temperature, the rate of a chemical reaction is directly proportional to the product of the molar concentrations of reacting species, with each concentration term raised to the power equal to the numerical coefficient of that species in that chemical equation"
For any general reaction
$aA+bB\to$ Products
Rate $=k[A{]}^a[B{]}^b$
i.e., Rate $\propto [A{]}^a[B{]}^b$