Final answer:
The rate law for the elementary reaction A + B → C + D is rate = k[A][B]. The rate law for a different elementary reaction x(R) + y(g) → z(g) is rate = k[x][y].
Step-by-step explanation:
The rate law for the elementary reaction A + B → C + D is written as:
rate = k[A][B]
In this case, the rate law is first order with respect to both reactants, A and B. This means that the rate of the reaction is directly proportional to the concentrations of A and B.
The rate law for a different elementary reaction x(R) + y(g) → z(g) is also written as:
rate = k[x][y]
In this case, the rate law is again first order with respect to both reactants, x and y.