Given: solubility (g/100g H2O)

temp degrees celcius KBR
20 65
40 80
60 90
80 100
100 110

A solution containing 10.5g of KBr in 10g of H2O at 100 degrees celcius is cooled to 40 degrees celcius.

A)calculate the g/100g H2O of KBr
B)is the solution saturated at 100 degrees celcius?
C) Is the solution saturated at 40 degrees celcius?
D) How much solid is formed during the cooling?

1 answer

Note the correct spelling of celsius.

a) Convert 10.5 g KBr/10 g H2O to g KBr/100 g H2O, then compare with your table.
10.5 g KBr x (100 gH2O/10 g H2O) = 105 g KBr/100 g H2O. Your table says you can dissolve 110 g KBr at 100.
b)Look at the numbers.
c) Compare the numbers at 40 C.
d)If you had 110 g at 100 C and you can hold 80 g at 40C then 110-80 must be amount that crystallizes when cooled from 100 to 40.