Question

the solubility of a compound is 59 g / 100 ml in boiling methanol and 30 g / 100 ml in cold methanol. if you take 59g of compound and dissolve it in 100 ml of methanol and then cool it down to 0°c and filter it (as above), you would recover ______ % (round your answer to 2 significant figures)

Explanation:

Step1: Determine amount of compound remaining in solution at 0°C

The solubility of the compound in cold methanol is 30 g/100 mL. When 59 g of the compound is dissolved in 100 mL of methanol and cooled to 0°C, the amount of compound that remains dissolved is 30 g.

Step2: Calculate amount of compound recovered

The amount of compound recovered is the initial amount minus the amount remaining in solution. Initial amount = 59 g, amount remaining in solution = 30 g. So, amount recovered = 59 - 30=29 g.

Step3: Calculate percentage of compound recovered

The percentage of compound recovered is given by the formula $\frac{\text{amount recovered}}{\text{initial amount}}\times100\%$. Substituting the values, we get $\frac{29}{59}\times 100\% \approx 49\%$.

Answer:

49%