A stockroom attendant has a 15.0%(w/v) solution of KOH. What volume of this solution should she use if she needs to prepare 20.0 mL of a 10.0%(w/v) solution?
A) 6.67 mL
B) 7.50 mL
C) 13.3 mL
D) 15.0 mL

Question

Quizplus · Accepted Answer

To prepare a 20.0 mL solution at 10.0% w/v from a 15.0% w/v solution, we use the dilution formula: C1V1 = C2V2. Here, C1 = 15.0%, V1 is unknown, C2 = 10.0%, and V2 = 20.0 mL. Solving for V1 gives V1 = (C2V2) / C1 = (10.0% * 20.0 mL) / 15.0% = 13.3 mL.

A Stockroom Attendant Has a 15