In: Chemistry
Write the balanced complete ionic equations and net ionic equations for the reactions that occur when each of the following pairs of solution are mixed. (Use the lowest possible coefficients. Include states-of-matter under SATP conditions in your answer.)
A) (NH4)3PO4(aq) and CaCl2(aq)
The reaction that will follow after mixing the two solutions is given below. Calciumphosphate has very low solubility in water hence it will precipitate out, and is shown as solid.
(NH4)3PO4(aq) + CaCl2(aq) ------> Ca3(PO4)2 (s) + NH4Cl (aq)
Balancing
1. balance the oxygen atom first as it has the highst number of atoms in the reaction.
There are 8 oxygen atoms in RHS and 2 in LHS, hence multiply ammonium sulphate by 2 on LHS.
2(NH4)3PO4(aq) + CaCl2(aq) ------> Ca3(PO4)2 (s) + NH4Cl (aq)
2. There are three Ca atoms on RHS and one in LHS, hence multiply CaCl2 on LHS by 3.
2(NH4)3PO4(aq) + 3CaCl2(aq) ------> Ca3(PO4)2 (s) + NH4Cl (aq)
3. Then multiply the NH4Cl by 6 to equate NH4+ and Cl- ions. Hence the balanced equation is
2(NH4)3PO4(aq) + 3CaCl2(aq) ------> Ca3(PO4)2 (s) + 6NH4Cl (aq)
(B) NET IONIC EQUATION>
While writing net ionic equation we cancell out the identical ions that figure in LHS and RHS.
6 (NH4)+(aq) + 2PO43- (aq) + 3Ca2+ (aq) + 6Cl-(aq) ------> Ca3(PO4)2 (s) + 6NH4+(aq) + 6Cl- (aq)
NET IONIC EQUATION
2PO43- (aq) + 3Ca2+
(aq) ------> Ca3(PO4)2 (s)