I have to write the rate law for two elementary reaction equations

A ) 2a+b>c+d

B ) X+Y>Z

I'm pretty sure it's just k[ A ][ B ] and k[ X ][ Y ] but does the coefficient affect it in this case? is it [ A ]^2 ?

For the first reaction equation, 2a + b > c + d, the rate law can be written as:

Rate = k [A]^2 [B]

The reaction rate is directly proportional to the square of the concentration of A since the coefficient in front of A is 2.

For the second reaction equation, X + Y > Z, the rate law can be written as:

Rate = k [X] [Y]

In this case, the coefficient of 1 does not affect the rate law. The reaction rate is directly proportional to the concentration of X and Y.

To write the rate law for a reaction, you need to determine the order of each reactant in the rate equation. The order of a reactant is determined by its coefficient in the balanced chemical equation for the reaction.

In the given reaction equations:

A) 2a + b > c + d
B) X + Y > Z

For reaction A, the rate law would be written as: rate = k [A]^x [B]^y
Since the coefficient for reactant A is 2, the order of A would be 2. Therefore, the rate law for reaction A would be: rate = k [A]^2 [B]^y

For reaction B, the rate law would be written as: rate = k [X]^x [Y]^y
Since there are no coefficients listed in the reaction equation, the order for both X and Y would be 1. Therefore, the rate law for reaction B would be: rate = k [X]^1 [Y]^1, which simplifies to rate = k [X] [Y].

So, to summarize:
- For reaction A: rate = k [A]^2 [B]^y
- For reaction B: rate = k [X] [Y]

The coefficients in the balanced equation do affect the rate law, as they determine the order of the reactants in the rate equation.