Scheduled maintenance: Saturday, March 6 from 3–4 PM PST
Only $2.99/month

Chemistry - Chemical reactions - Precipitation reactions

Terms in this set (12)

Beaker 1
The ions present in the solution before they are mixed are K+, I-, Pb2+, NO3-. When the two colourless solutions of potassium iodide and lead nitrate are mixed together a yellow precipitate of PbI2 is formed and the K+ and NO3- ions remain in the solution as spectator ions. A yellow precipitate of PbI2 is formed because the attraction of lead ions to iodide ions is stronger than the attraction of lead ions to water and iodide ions to water. K+ and NO3- ions remain in the solution because according to the solubility rules all nitrate ions are soluble

Beaker 2
No precipitate is formed in beaker 2. The ions present in the solution before they are mixed are Na+, Cl-, Fe3+, NO3-. After the two colourless solutions of sodium chloride and iron (III) are mixed together all the ions remain in the solution because according to the solubility rules all nitrates are soluble and all chlorides are solution expect AgCl and PbCl2 so no precipitate is formed

Beaker 3
In Beaker 3 a blue precipitate of Copper hydroxide is formed. The ions present in the solution before they are mixed are Cu2+, SO42-, Na+, OH-. When the blue solution of Copper hydroxide is mixed with the colourless solution of sodium hydroxide a blue precipitate of copper hydroxide is formed, because according to the solubility rules all hydroxides are insoluble except KOH and NaOH. Also because the attraction of copper ions to hydroxide ions is stronger than the attraction of copper ions to water and hydroxide ions to water. The Na+ and SO42- ions remain in the solution after the two solutions have been mixed as spectator ions because according to the solubility rules all sulfates are soluble except PbSO4, CaSO4, BaSO4.

Pb2+(aq) + I-(aq) ---> PbI2(s)
Cu2+(aq) + 2OH-(aq) ---> Cu(OH)2