Question

How many grams of solid K2CO3 are needed to prepare 150. mL of a 0.50% by volume K2CO3 solution ?

Answer 1

Answer:

0.75 g of K2CO3

Explanation:

• To prepare 150. mL of a 0.50% by volume K2CO3 solution;
• It means 0.5% w/v in 150 mL.
• Therefore, there would be 0.5 of K2CO3 in 100 mL of the solution.

• Taking the density of the solution to be equivalent to the density of water, that is, 1 g/ml.

• The mass of the solution will be; 150 mL × 1 g/mL = 150 g

Therefore; the mass of K2CO3 will be;

  = 0.5/100 × 150 g

  = 0.75 g