equilibrium expression?

Question

What is the equilibrium expression for the following reaction: CH4 (g) + Cl2 (g) CH3Cl (g) + HCl (g)? a)[Cl2][CH3Cl]/[CH4][HCl] b)[CH4][Cl2]/[CH3Cl][HCl]
c)[CH3Cl][HCl]/[CH4][Cl2]

What is the equilibrium expression for the following reaction: Hg (g) + I2 (g) HgI2 (g)? a)[HgI2]/[Hg][I2] b)[Hg][I2]/[HgI2]
c)[Hg]/[HgI2][I2]

What is the equilibrium expression for the following reaction: SnO2 (s) + 2 CO (g) Sn (s) + 2 CO2 (g)? a)[Sn][CO2]2/[SnO2][CO2] b)[SnO2][CO]2/[Sn][CO2]2
c)[CO2]2/[CO]2

What is the equilibrium expression for the following reaction: C (s) + CO2 (g) 2CO (g) a)[C][CO2]/[CO]2 b)[CO]2/[CO2]
c)[CO2]/[CO]2

Answer 1

c, a, c, b