Question

Complete the table below by deciding whether a precipitate forms when aqueous solutions A and B are mixed. If a precipitate will form, enter its empirical formula in the last column.

solution A solution B Does a precipitate form when A and B are mixed? empirical formula of precipitate sodium chloride ammonium bromide yes no magnesium bromide sodium hydroxide yes no cadmium nitrate manganese(II) iodide yes no

Answer 1

When Ammonium bromide is treated with sodium chloride, it forms ammonium chloride and sodium bromide

NaCl (aq) + NH₄Br (aq) ----------> NH₄Cl (aq)+ NaBr (aq)

The formed products both ammonium chloride (NH4Cl) and Sodium Bromide ( NaBr) are water soluble. Hence no precipitate is formed.

b)

When magnesium Bromide is treated with sodium hydroxide, magnesium hydroxide is precipitated.

MgBr_​​​2 (aq) + 2NaOH (aq) ---------> Mg(OH)₂ (s) + 2 NaBr (aq)

Formula of precipitate :  Mg(OH)₂ (s)

c)

When Cadmium nitrate is treated with Magnesium iodide, Cadmium iodide and magnesium nitrate are formed.

Cd(NO₃)₂ (aq) + MgI_{​​​​2} (aq) ------------> CdI_{​​​​2} (aq) + Mg(NO_{​​​​​3}​)₂ (aq)

No precipitate is formed as cadmium iodide and magnesium nitrate are water soluble