Answer : The correct option is, \((4):2.0MHCl(aq)\text{ at }40^oC\)
Explanation :
Le-Chatelier's principle : It states that the change in the variables of the reaction, the equilibrium will shift in that direction where the effect will be minimum.
The rate of reaction is directly related to the concentration of the reactants and the temperature of the reaction.
If the concentration of the reactant increases, the equilibrium will shift in the forward direction that means the rate of reaction increases and if the concentration of the reactant decreases, the equilibrium will shift in the backward direction that means the rate of reaction decreases.
If the temperature of the reaction increases then rate of reaction also increases and vice-versa.
Thus, the rate of reaction is greater at high concentration and temperature.
Hence, the correct option is, \((4):2.0MHCl(aq)\text{ at }40^oC\)
