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write ionic and net ionic equations for the following
reactions:
(a) na2s(aq) + zncl2(aq) →
(b) k3po4(aq) + 3sr(no3)2(aq) →→
(c) mg(no3)2(aq) + 2naoh(aq) →

(a)  

First, write the balanced equation as follows:

Na2S(aq) + ZnCl2(aq) -> 2 NaCl(aq) + ZnS  (s)

Then, rewrite the equation so that all dissolved compounds are separated into their constituted ions. This is called, total ionic equation:

Finally, cancel the ions that appear both in reactants and products. This is called, net ionic equation:

(b)

Balanced equation:

2 K3PO4(aq) + 3Sr(NO3)2(aq) -> Sr3(PO4)2 (s) + 6 KNO3 (aq)

Total ionic equation:

Net ionic equation:

(c)

Balanced equation:

Mg(NO3)2(aq) + 2NaOH(aq) -> Mg(OH)2 (s) + 2 NaNO3 (aq)

Total ionic equation:

Net ionic equation:

2b2t

explanation:

2b2t

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8