5.6 2 Precipitation reactions

Question 1

Carbon Dioxide Chemical Test

Answer 1

calcium hydroxide solution (limewater),a white precipitate of calcium carbonate forms
CaOH(aq)+CO2(g)=CaCO3(s)+H2O(l)
“going milky or cloudy”

Question 2

Sulfates

Answer 2

addition of barium ions (barium chloride or barium nitrate)
white precipitate is barium sulphate
barium is more reactive

Question 3

Halides

Answer 3

addition of silver ions

Question 4

working out equations

Answer 4

take the example of lead nitrate +potassium iodide =lead iodide +potassium nitrate
1.place same volume of potassium iodide in a series of test tubes
2.add different volumes of lead nitrate solution to the tubes
3.place each tube in the centrifuge and spin the tubes
for the same length of time
4.measure depth of precipitate

Question 5

calculations

Answer 5

need conc of solutions ,volume and depth of precipitate

see where there is no long an increase in precipitate first one then use conc from them