Rate equation for relative rate of disappearance?

1 of the few reagents that can dissolve gold is aqua regia. Aqua regia quickly breaks down to form nitrosyl chloride, nitrogen monoxide, and chlorine gas, which exists in equilibrium. Cl2(g)+2NO(g) <->2NOCl(g). What are the rate equations for the relative rate of disappearance of chlorine gas and nitrogen monoxide and appearance of nitrosyl chloride? Please help!