What is the difference between average rate and instantaneous rate of a chemical reaction?
For an average rate of reaction, the change in concentration is measured over longer interval of time.
But when the change in concentration is measured over smaller interval of time, it is called instantaneous rate of reaction.
What is temperature coefficient?
It is the ratio of the rate constants of a reaction at two different temperatures differing by 100. The value is found to be between 2 and 3.
Differentiate between rate of reaction and specific reaction rate.
Rate of reaction is the speed at which reactants are converted to products. It depends upon concentration of reactants and decrease with the progress of reaction.
Specific reaction rate is constant in the rate equation of the reaction. It refers to the rate of a reaction at a specific condition when concentration of reaction is unity.
Explain why H2 and O2 do not combine with each other at room temperature.
At room temperature, the energy of H2 and O2 is not sufficient to cross the threshold energy. Thus they do not react with each other at room temperature. But on giving an electric spark to the mixture, a vigorous reaction takes place at room temperature.
Why does zinc dust react faster with dilute HCl than zinc granules?
Zinc dust has more surface area than zinc granular. Thus, zinc dust comes in contact with more hydrochloric acid than Zn granules. Thus, zinc dust dissolves faster than zinc granules in hydrochloric acid.
Why the hydrolysis of ethyl acetate with NaOH is a second order reaction while with HCl, it is of first order.
In case of ethyl acetic and sodium hydroxide, the rate depends upon the molar conc. of both the reactants while in the hydrolysis with HCl, the rate depends upon the molar conc. of only ethyl acetate.
The half life period of a first order reaction is x and three fourth of the same reaction is y. How are x and y related to each other?
Y should be twice of x. The reason is that the time required for 3/4thof a reaction to occur is two times that required for half of the reaction.


Can activation energy of a reaction be zero?
From Arrhenius equation, k=A e-Ea/RT.
If Ea=0, then k= A  i.e., every collision between molecules leads to a chemical reaction. It is not true. Activation energy (Ea) cannot be equal to zero.
The use of instantanous rate of reaction is preferred over average rate of reaction Comment.
The rate of reaction continuously decreases with time and therefore, average rate has no significance for the reaction.






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