Question

For a chemistry experiment Laura needs 300 ml of a 15% sulphuric acid solution. The Science Department has quantities of 5% acid solution and 20% acid solution. What volume of each solution is required to mix together to get her required concentration? Use a complete algebraic solution, including a proper verification.

Answer 1

Answer


For future reference, the fact that an equation has integer coefficients does not require that the solutions to those questions be integers. Decimal or fractional solutions of systems of equations are far

Answer 2

100 ml of 5% solution

200 ml of 20% solution

Explanation:

x = amount of 5% solution

y = amount of 20% solution

System of equations:

x + y = 300

.05x + .20y = 300(.15)

Solve by substitution: let y = 300 - x

.05x + .2(300-x) = 300(.15)

.05x + 60 - .20x = 45

-.15x = -15

x = 100, therefore y = 200