Question

The chemical solution contains 40% salts. if you add 120 g of salt, the solution will contain 70% salt. find the mass of salt in the initial solution.

Answer 1

To solve the problem, one must set up the equation 0.40x + 120g = 0.70(x + 120g) using percentage by mass, where x represents the initial mass of the solution. By solving this equation, one can find the mass of salt in the initial solution.

Step-by-step explanation:

The question relates to the concept of percentage by mass in a chemical solution, which falls under the subject of mathematics, specifically algebra and analytical skills in relation to chemistry.

Initially, the solution contains 40% salts. When 120g of salt is added, the solution is then said to have 70% salts. To find the mass of salt in the initial solution, one can use the concept of percentages to set up an equation. Let x be the total mass of the solution before additional salt is added. The mass of salt initially present is then 0.40x. After adding 120g salt, the total mass of the solution becomes x + 120g, and the mass of salt becomes 0.40x + 120g. According to the problem, at this point, the mass of salt is 70% of the total mass, or 0.70(x + 120g).

To find the value of x, we set up the following equation:

0.40x + 120g = 0.70(x + 120g)

By solving this equation, we can find the initial mass of the solution, and from there calculate the mass of salt it contained.