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Read the passage given below and answer the questions that follow : The rate law for a chemical reaction relates the reaction rate with the concentrations or partial pressures of the reactants. For a general reaction aA + bB → C with no intermediate steps in its reaction mechanism, meaning that it is an elementary reaction, the rate law is given by r = k[A]x[B]y, where [A] and [B] express the concentrations of A and B in moles per litre. Exponents x and y vary for each reaction and are determined experimentally. The value of k varies with conditions that affect reaction rate, such as temperature, pressure, surface area, etc. The sum of these exponents is known as overall reaction order. A zero order reaction has a constant rate that is independent of the concentration of the reactants. A first order reaction depends on the concentration of only one reactant. A reaction is said to be second order when the overall order is two. Once we have determined the order of the reaction, we can go back and plug in one set of our initial values and solve for k.
Answer the following questions (Do any two) :
The rate law for a particular reaction is given as rate = k[A][B]². How is the rate of reaction affected if we double the concentration of B ? Choose the correct option :
A reaction is first order in X and second order in Y.
Reactant 'A' underwent a decomposition reaction. The concentration of 'A' was measured periodically and recorded in the table given below : Time/Hours | [A]/M 0 | 0·40 1 | 0·20 2 | 0·10 3 | 0·05 Based on the above data, predict the order of the reaction and write the expression for the rate law.
The reaction between H₂(g) and I₂(g) was carried out in a sealed isothermal container. The rate law for the reaction was found to be : Rate = k[H₂] [I₂] If 1 mole of H₂(g) was added to the reaction chamber and the temperature was kept constant, then predict the change in rate of the reaction and the rate constant.
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