Question

The technician has 20 ml of a 18% solution. after adding diluent, the technician has 400 ml of solution

a)True
b)False

Answer 1

The statement is false because after dilution the final concentration of the solution is reduced to 0.9%, whereas the original concentration was 18%.

Step-by-step explanation:

The question is asking whether it's true or false that if a technician has 20 mL of an 18% solution and after adding enough diluent such that the final volume is 400 mL, the resulting solution will still be the original concentration. To answer, we need to use the concept of concentration dilution, which is often described by the formula C1V1 = C2V2 where C1 and V1 are the initial concentration and volume, and C2 and V2 are the final concentration and volume.

Let's first find the amount of substance in the original solution: 20 mL * 18% = 3.6 mL of active substance. After dilution, if the final volume is 400 mL, to find the concentration of the diluted solution we calculate 3.6 mL / 400 mL = 0.009 or 0.9%. Therefore, the statement is false, since the concentration of the diluted solution is now 0.9% and not the original 18%.