How many grams of iodine and alcohol do you need to take to prepare 30g of a 5% solution of iodine tincture?

The mass of the solution is 30 grams;

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

m iodine = 30 x 0.05 = 1.5 grams;

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

m of alcohol = 30 – 1.50 = 28.5 grams;

Check: 1.5 + 28.5 = 30;