Statement I: Rate of reaction decreases with increase in concentration

Statement II: Rate of reaction remains constant for every temperature

Statement I is false but statement II is correct

The correct answer is: 4.Statement I is false, but Statement II is correct.
 
Statement I: The rate of reaction decreases with an increase in concentration.
This statement is generally false. In most cases, the rate of a chemical reaction increases with an increase in concentration. This is because a higher concentration of reactants leads to a higher frequency of collisions and a greater chance of successful collisions, resulting in an increased reaction rate. However, there may be exceptions where the rate of reaction decreases with increasing concentration due to factors such as complex reaction mechanisms or interactions between reactant molecules.

Statement II:  The rate of reaction remains constant for every temperature.
This statement is true. The rate of a reaction does not remain constant for every temperature. The rate of reaction is generally temperature-dependent, and an increase in temperature often leads to an increase in the reaction rate. This is because at higher temperatures, reactant molecules possess higher kinetic energy, resulting in more frequent collisions and a higher probability of successful collisions. The rate constant, which is an inherent property of the reaction, can change with temperature as it is affected by factors such as activation energy and temperature dependence factors (e.g., Arrhenius equation).

Therefore, Statement I is false, and Statement II is true.