Question

How many grams of each of the following substances will dissolve in 100 ml of cold water; Ce(IO3)4, RaSO4, (NH4)2SeO4?

Answer 1

Answer: $Ce(IO_3)_4$ = 0.123g , $RaSO_4$  = $2.1*10^-^4g$ and $(NH_4)2SeO_4$ = 96 g

Explanations: The question asks about the solubility of each of the compounds in grams per 100 mL of water. density of water is 1 gram per mL. So, 100 mL of water would be same as 100 g water.

In solubility charts, the solubilities are also shown in grams of compound per 100 grams of water.

Solubility of $Ce(IO_3)_4$ is 0.123 g, solubility of $RaSO_4$ is 0.00021  g and the solubility of $(NH_4)2SeO_4$ is 96 g per 100 g of water.

Since the question also asks about grams of each soluble in 100 mL that is 100 g of water, the grams of each salts will be same as their  above solubilities that is, $Ce(IO_3)_4$ is 0.123 g, $RaSO_4$ is 0.00021  g and the solubility of $(NH_4)2SeO_4$ is 96 g.

Answer 2

The solubility of Ce(IO3)4, RaSO4, (NH4)2SeO4 in water are  0.123, 2.1x10^-4 and 96 in units of g/100 mL. Therefore, given 100 mL of water 0.123 g of Ce(IO3)3, 2.1x10^-4 g of RaSO4 and 96 g of (NH4)2SeO4 can be dissolve. Hope this helps.