The iodine tincture used in medicine is a 5% solution of crystalline iodine in ethyl alcohol, calculate the volume of alcohol

The iodine tincture used in medicine is a 5% solution of crystalline iodine in ethyl alcohol, calculate the volume of alcohol, the density of which is 0.8 g, ml of 250 g of such a solution required for the preparation.

The mass of the solution is 250 grams;

To find the mass of iodine, it is necessary to multiply its mass fraction by the mass of the solution.

m iodine = 250 x 0.05 = 12.5 grams;

To find the mass of alcohol, subtract the mass of iodine from the mass of the solution:

m of alcohol = 250 – 12.5 = 237.5 grams;

The density of alcohol is 0.8 grams / cm3. To prepare this solution, you need to measure 237.5 x 0.8 = 190 milliliters of alcohol.

Check: 237.5 + 12.5 = 250;