Question

The solubility of sugar is 203.9 g/100 g H2O at 20°C. To make candy from crystallized sugar, 300.0 g of sucrose is dissolved in 75 g of water at 100°C. To the nearest gram, how much sugar crystallized out of the saturated solution when it cooled to 20 C?

Answer 1

75 g of water at 20 degrees C would hold dissolved (203.9 g) x (75/100) =
152.9 g of sugar.

(300.0 g initially) - (152.9 g remaining in solution) = 147.1 g sugar crystallize out

So answer A.

Answer 2

Answer : The amount of sugar crystallized out of the saturated solution when it cooled to
`20^oC` is, 147 grams.

Solution :

First we have to calculate the amount of sugar remains in the solution.

As, 100 gram of water contains 203.9 gram of sugar

So, 75 gram of water contains
`(203.9g)/(100g)* 75g=152.9g` of sugar

Now we have to calculate the amount of sugar crystallized out of the saturated solution.

`\text{The amount of sugar crystallized out}=\text{Initial sugar}-\text{Remaining in the solution}`

`\text{The amount of sugar crystallized out}=300g-152.9g=147.1=147g`

Therefore, the amount of sugar crystallized out of the saturated solution when it cooled to
`20^oC` is, 147 grams.