Question

A Chemistry teaching assistant needs 10 liters of a 20% saline solution (salt water) for his 2 p.m. laboratory class. Unfortunately, the only mixtures on hand are a 5% saline solution and a 25% saline solution. How much of each solution should be mix to produce the 20 percent solution?

Answer 1

Answer:

7.5 litres of 25% saline solution; 2.5 litres of 5% saline solution

Step-by-step explanation:

• Consider number of litres of 25% saline solution as x; thus, number of litres of 5% saline solution is (10 - x)
• Now, the required equation to get the solution can be written as -
• 0.25*x + (10 - x)*0.05 = 0.2*10
• i.e. 0.25x + 0.5 - 0.05x = 2
• i.e. 0.2x = 2 - 0.5
• i.e. 0.2x = 1.5
• i.e. x = 1.5 / 0.2
• i.e. x = 7.5
• i.e. Number of litres of 25% saline solution = x = 7.5 litres
• Thus, Number of litres of 5% saline solution = 10 - x = 10 - 7.5 = 2.5 litres

Answer 2

Answer:

The answer would be 2.5 liters of the 5% and 7.5 liters of the 25%

Step-by-step explanation: