which of the following are examples of single replacement reactions select all that apply.
1) Ca(OH)2(aq) + 2 HCl(aq) ----> CaCl2(aq) + 2 H2O(l)
2)Mg(s) + Zn(NO3)2(aq) ------> Mg(NO3)2(aq) + Zn(s) 3)Na2S(aq) + Cd(NO3)2(aq) ----> 2 NaNO3(aq)
4) K(s) + 2HCl(aq) ----> 2KCl (aq) +H2(g)