The reaction between chloroform, CHCl3(g) and chlorine Cl2(g) to form CCl4(g) and HCl(g) is believed to occur by this series of steps:
Step 1: Cl2(g)⟶Cl(g)+Cl(g)
Step 2: CHCl3(g)+Cl(g)⟶CCl3(g)+HCl(g)
Step 3: CCl3(g)+Cl(g)⟶CCl4(g)
If this reaction is first order in CHCl3 and half order in Cl2, which statement about the relative rates of steps 1, 2 and 3 is correct?