Saturated solutions of each of the following compounds are made at 20 degree Celsius. Which of the solutions will form a precipitate upon heating?

a. NaCl b. Na2SO4
c. Li2CO3 d. sucrose

Since water heats at 100 degree Celsius here are there solubility (g/100 g of H2O) measurements
for a. 39.2 b. 41.0 c. 0.70 d. 487

Can you explain to me how you got the answer?

1 answer

Frankly, I don't understand the data table. It's nice to know the solubility but what is the temperature? 100 C perhaps? And what is the saturated solution of each? The answer, I believe, is Na2SO4. The solubility curve for Na2SO4.10H2O decreases above about 30 C.
http://en.wikipedia.org/wiki/Sodium_sulfate