# Question 4e2cd

Nov 10, 2016

First, write out the likely reaction products in chemical equation form. The molecular equation must be balanced to ensure that equal numbers of each element are on each side of the equation.

#### Explanation:

First, write out the likely reaction products in chemical equation form. To know if a precipitate is likely to form, look up each products solubility constant. If no precipitate forms, the ions will essentially stay in solution independently, and there is no net “reaction”.

The molecular equation must be balanced to ensure that equal numbers of each element are on each side of the equation. From each pair of reactants, we expect a switching of “partners” (double displacement), so the expected products are just the original compounds with their front/back names swapped.

A. sodium nitrate and lead(II) acetate → sodium acetate + lead (II) nitrate
2NaNO_3 + PbC_2H_3O_2 → Na_2C_2H_3O_2 + Pb(NO_3)_2

B. silver nitrate and strontium iodide→silver iodide + strontium nitrate
2AgNO_3 + SrI_2 → 2AgI + Sr(NO_3)_2
C. cesium chloride and calcium sulfide → cesium sulfide + calcium chloride
2CsCl + CaS → Cs_2S + CaCl_2

D. aluminum sulfate and sodium phosphate → aluminum phosphate + sodium sulfate
Al_2(SO_4)_3 + 2Na_3PO_4 →2AlPO_4 + 3Na_2(SO_4)#