Cucl2(aq)+na2s(aq)→cus(s)+2nacl(aq)
Write the net ionic equation for this reaction.

Cu^2+ (aq) + S^2- (aq) --> CuS (s)

Explanation:

Break up all the soluble compounds into their constituent ions to get the complete ionic equation, and cross off the ones that appear the same on both sides:

Cu (aq) + 2Cl(aq) + 2Na (aq) + S (aq) --> CuS (s) + 2Na (aq) + 2Cl (aq)

2Cl and 2Na appear on both sides of the arrow, so cross those out to get the net ionic equation.