Question

at 30degrees celcius, 80 grams of potassium bromide is dissolved in 100 grams of water. is this solution unsaturated, saturated, or supersaturated.

Answer 1

You need to have a graph of the solubility or a table listing the solubility. I don't have those.
Note the correct spelling of Celsius.

Answer 2

You'd have to look up the solubility of that compound in water to come up with an answer. I am surprised that they would assign such a question in 9th grade science. My handbook of physics and chemistry states that 53 grams of KBr will dissolve in 100 g of water at 0 C and 102 g will dissolve at 100 C. It is likely that about 65-75 g will dissolve in a saturated solution at 30 C. That would mean the solution is supersaturated. It could however be saturated. It is too close to call with the data I have. My handbook does not have the solubility at 30 C.

Were you possibly given a graph of solubility vs. temperature as part of this question? If so, that will tell you the answer.

Answer 3

My supposition was that a graph was furnished.

Answer 4

This solution is supersaturated because solubility of KBr at 30*C is 70.7 so it is supersaturated