How do you predict the product of a reaction?

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Please help me, this is my fourth time uploading this question with varying titles.

1 Answer
Mar 1, 2018

"2K"(s)+"Mg(OH)"_2(aq)->"Mg"(s)+"KOH"(aq)
"Cl"_2(g)+"MgI"_2(aq)->"MgCl"_2(aq)+"I"_2(s)
3"CuCl"_2(aq)+2"Na"_3"PO"_4(aq)->6"NaCl"(aq)+"Cu"_3("PO"_4)_2(s)
"BaCl"_2(aq)+"K"_2"SO"_4(aq)->2"KCl"(aq)+"Ba""SO"_4(s)

Explanation:

For single replacement, the rule is the more reactive metal replaces the less reactive cation in the aqueous solution, and for double replacement, a solid, liquid or gas must be formed.