The mass fraction of iodine in the pharmacy iodine tincture is 5%.

The mass fraction of iodine in the pharmacy iodine tincture is 5%. How much iodine and alcohol do you need to take to prepare 200 g of tincture?

The mass of the solution is 200 grams;

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

m iodine = 200 x 0.05 = 10 grams;

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

m of alcohol = 200 – 10 = 190 grams;

The density of alcohol is 0.8 g / cm3. To prepare this solution, you must measure 190 x 0.8 = 152 milliliters of alcohol.

Check: 190 + 10 = 200;