What type of reaction each one is, synthesis , decomposition , single displacement or double displacement?

a. zinc + copper (II) sulphate >>>> copper (II) + zinc sulphate

b. MG+ HCL >> H2 + MgCl2

1 answer

a isn't the correct equation.
Zn + CuSO4 ==> Cu + ZnSO4 and it appears to me that Zn is replacing Cu(II) so that would be single replacement.

What's happening in b?