A solution is made by diluting a standard solution by adding 25 mL of the standard solution to 75 mL of distilled water. What is the concentration of the resulting solution?

The concentration of the resulting solution is 0.25 or one quarter of the standard solution

Explanation:

Whereby the molar concentration of the standard solution is P molar per liter, we have

25 ml of the standard solution contains

25/1000×P moles of the standard solution such that the resultant solution has a volume of 25 + 75 = 100 ml contains 0.025 P moles of the standard solution

The concentration of a solution is the number of moles contained per liter, which gives

100 ml contains 0.025 P moles

1 liter = 1000 ml will contain 1000/100 × 0.025 = 0.25 P moles of the stanard solution

Therefore, the concentration of the resulting solution is 0.25 or one quarter of the standard solution.