Question

State the effect of adding a small amount of : (a) sodium hydroxide (b) ammonium hydroxide followed by an excess in case to samples of the salt solutions.
Lead nitrate [ small amount ________ in excess ________ ]

Answer 1

Lead nitrate :
a. with sodium hydroxide :

• \[\ce{Pb(NO)3 + 2NaOH -> Pb(OH)2 + 2NaNO3}\]
• White curdy ppt. is soluble in excess of NaOH.

b. With ammonium hydroxide :

• \[\ce{Pb(NO)3 + 2NH4OH -> Pb(OH)2 + 2NH4NO3}\]
• White curdy ppt. is insoluble in excess of ammonium hydroxide.