Precipitation in Double Displacement Precipitation in Double Displacement ReactionsReactions

Rimsha MumtazRimsha Mumtaz

David Bazan David Bazan

IntroductionIntroduction

A double displacement A double displacement reaction involves the reaction reaction involves the reaction of two compounds to form two of two compounds to form two new compounds. In effect, the new compounds. In effect, the compounds change partners compounds change partners with each other.with each other.

There are so many examples There are so many examples of double displacement of double displacement reaction. For example: When reaction. For example: When Silver Nitrate react with Silver Nitrate react with Sodium Chloride produce Sodium Chloride produce Sodium Nitrate and Silver Sodium Nitrate and Silver Chloride. This is a double Chloride. This is a double displacement reaction.displacement reaction.

Purpose, Material for these Purpose, Material for these reactions.reactions.

The purpose of these reactions is to The purpose of these reactions is to observe precipitation reactions by mixing observe precipitation reactions by mixing aqueous solutions of cations and anions.aqueous solutions of cations and anions.

The material which we need are following: The material which we need are following:

Pb(NOPb(NO33))22 AgNO AgNOKI KNOKI KNO 33

NaOH NaOH CaCl CaCl22NaNa22COCO33 NaCl NaClFeClFeCl3 3 CuSo CuSo44

Test Tubes Test RackTest Tubes Test Rack

Procedure of these reactionsProcedure of these reactions

1.1. We have to put 21 test tubes in a test tube rack.We have to put 21 test tubes in a test tube rack.2.2. Add 6 drops of the solution indicated which are: Add 6 drops of the solution indicated which are:

KI,NaCl,NaOH,FeClKI,NaCl,NaOH,FeCl33,KNO,KNO33,Na,Na22COCO33, CuSO, CuSO44. . 3.3. Add 6 drops of AgNOAdd 6 drops of AgNO33 solution to every tube. solution to every tube.4.4. We have to observe and record information and color We have to observe and record information and color

of precipitate formed .of precipitate formed .5.5. Do the same with Pb(NODo the same with Pb(NO33))22 and with CaCl and with CaCl22. . 6.6. Clean the test tubes and dispose of the wastes in the Clean the test tubes and dispose of the wastes in the

waste container.waste container.7.7. And finally write correctly equations for all of the And finally write correctly equations for all of the

reactions where a precipitate is formed.reactions where a precipitate is formed.

Reactions with AgNoReactions with AgNo33

When we add a small quantity of Potassium Iodide in When we add a small quantity of Potassium Iodide in Silver Nitrate it produced Potassium Nitrate and as a Silver Nitrate it produced Potassium Nitrate and as a precipitate produced Silver Iodide.precipitate produced Silver Iodide.

AgNOAgNO33 + KI + KI → KNO→ KNO33 + AgI↓ + AgI↓

Precipitate has got a Yellow colour. Precipitate has got a Yellow colour.

AgNOAgNO3 and NaCl3 and NaCl

When we add a small quantity When we add a small quantity of Sodium Chloride in Silver of Sodium Chloride in Silver Nitrate it produced Sodium Nitrate it produced Sodium Nitrate and as a precipitate Nitrate and as a precipitate formed Silver Chloride.formed Silver Chloride.

AgNO3 + NaCl AgNO3 + NaCl → NaNO3 + AgCl↓→ NaNO3 + AgCl↓

Precipitate has got white Precipitate has got white colour. colour.

AgNOAgNO33 and NaOH and NaOH

Silver Nitrate react with Sodium Silver Nitrate react with Sodium Hydroxide to form Sodium Nitrate Hydroxide to form Sodium Nitrate and Silver Hydroxide as a and Silver Hydroxide as a

precipitateprecipitate..

AgNOAgNO33 + NaOH + NaOH → NaNO→ NaNO33 + AgOH↓ + AgOH↓

The precipitate's colour was The precipitate's colour was Brown.Brown.

AgNOAgNO33 and FeCl and FeCl33

Iron Nitrate and Silver Iron Nitrate and Silver Chloride are produced Chloride are produced when Silver Nitrate react when Silver Nitrate react with Iron(III) Chloridewith Iron(III) Chloride. .

AgNOAgNO33 + FeCl + FeCl33 → FeNO→ FeNO3 3 + + AgClAgCl33↓↓

The precipitate colour The precipitate colour was light Yellowwas light Yellow. .

AgNOAgNO33 and KNO and KNO33

When Silver Nitrate and When Silver Nitrate and Potassium Nitrate react Potassium Nitrate react produced equal products produced equal products Because Silver take Because Silver take place of Potassium and place of Potassium and Potassium take place of Potassium take place of Silver.Silver.

AgNOAgNO33 + KNO + KNO33 → KNO→ KNO33 + + AgNOAgNO33

The precipitate was Semi The precipitate was Semi Transparent.Transparent.

AgNOAgNO33 and Na and Na22COCO33

Silver Nitrate and Sodium Silver Nitrate and Sodium Carbonate react to form Carbonate react to form Sodium Nitrate and Silver Sodium Nitrate and Silver Carbonate. The precipitate Carbonate. The precipitate is Silver Carbonate. is Silver Carbonate.

AgNOAgNO3 3 + Na2CO+ Na2CO3 3 → Na→ Na22COCO3 3 + + AgCOAgCO33↓↓

Precipitate’s colour is light Precipitate’s colour is light Green. Green.

AgNOAgNO33 and CuSO and CuSO44

Copper nitrate and Silver Copper nitrate and Silver Sulphurate are form when Sulphurate are form when Silver Nitrate and Copper Silver Nitrate and Copper Sulphurate react with each Sulphurate react with each other. The precipitate is other. The precipitate is Silver Sulphurate.Silver Sulphurate.

AgNOAgNO3 3 + CuSO+ CuSO44 → CuNO→ CuNO33 + AgCO+ AgCO33

The colour of precipitate is The colour of precipitate is very light blue.very light blue.

Reactions with Lead (II) NitrateReactions with Lead (II) Nitrate

Potassium nitrate and Potassium nitrate and Lead Iodide are formed Lead Iodide are formed when Lead (II) Nitrate when Lead (II) Nitrate react with Potassium react with Potassium Iodide . The precipitation Iodide . The precipitation is Lead Iodide.is Lead Iodide.

Pb(NOPb(NO33))22 + 2KI + 2KI → → 2KNO2KNO33 + PbI + PbI22

The precipitation’s colour The precipitation’s colour is Yellow.is Yellow.

Pb(NOPb(NO33))22 and KI and KI

When Lead (II) Nitrate When Lead (II) Nitrate react with Sodium react with Sodium Chloride it produced Chloride it produced Sodium Nitrate and Lead Sodium Nitrate and Lead (II) chloride.(II) chloride.

Pb(NOPb(NO33) + 2NaCl ) + 2NaCl →2NaNO→2NaNO3 3 + PbCl+ PbCl22

The precipitation has got The precipitation has got white colour.white colour.

Pb(NOPb(NO33))2 2 and NaOHand NaOH

Sodium Nitrate and Lead (II) Sodium Nitrate and Lead (II) Hydroxide are formed when Hydroxide are formed when Lead (II) Nitrate and Sodium Lead (II) Nitrate and Sodium Hydroxide react with each Hydroxide react with each other.other.

Pb(NOPb(NO33))22 + 2NaOH + 2NaOH → → 2NaNO2NaNO33 + Pb(OH) + Pb(OH)22

The precipitation has got a The precipitation has got a white colour. white colour.

Pb(NO3)2 and KNO3Pb(NO3)2 and KNO3

When Lead (II) Nitrate and When Lead (II) Nitrate and Potassium Nitrate react with Potassium Nitrate react with each other it produced equal each other it produced equal products as reactants products as reactants because Potassium take because Potassium take place of Lead and Lead takes place of Lead and Lead takes place of Potassium so it place of Potassium so it produced same. produced same.

Pb(NOPb(NO33))22 + KNO + KNO3 3 → → KNOKNO33 + PbNO + PbNO33

The precipitate’s colour is The precipitate’s colour is

transparent whitetransparent white. .

Pb(NOPb(NO33))22 and Na and Na22COCO33

When Lead (II) Nitrate and When Lead (II) Nitrate and Sodium Carbonate it Sodium Carbonate it produced Sodium Nitrate produced Sodium Nitrate and Lead Carbonate as a and Lead Carbonate as a precipitate.precipitate.

Pb(NOPb(NO33))22 + Na + Na22COCO33 → → NaNa22NONO33 + PbCO + PbCO33

The The precipitateprecipitate has got has got White colour.White colour.

ConclusionConclusion

The two cations which form most precipitates are Ag+ and The two cations which form most precipitates are Ag+ and Pb2+.Pb2+.

Thanks for your attention