Activity 4 – Solubility

1. Look at the solubility graphs in the attached figure and mark the correct answer in each case. You do NOT need to justify your answer.
a) When 30 grams of potassium chlorate, KClO3, are dissolved in 100 grams of water at 70ºC, the dissolution can be described as...
a1) oversaturated
a2) unsaturated
a3) saturated

b) When we dissolve 50 grams of potassium chloride, KCl, in 100 grams of water at 50ºC, the dissolution can be described as:
b1) oversaturated
b2) unsaturated
b3) saturated

c) Which salt is LEAST soluble at 50ºC?

d) In a beaker mix 80 grams of lead(II) nitrate, Pb(NO3)2, in 100 grams of water at a temperature of 30ºC. Approximately how many grams of the salt will remain undissolved at the bottom of the beaker?

e) How many grams of sodium nitrate, NaNO3, can be dissolved in 100 g of water at 10ºC?

f) Which salt experiences a decrease in solubility when the temperature increases?

g) Which salt is MOST soluble at 0 ºC?

h) A solution of potassium chlorate, KClO3, has 20 grams of the salt dissolved in 100 grams of water at 70 ºC. Approximately how many more grams of salt can we add to the solution before we reach the saturation point?

At approximately what temperature do the solubilities of sodium chloride, NaCl, and potassium dichromate, K2Cr2O7, match?