Answer: 68.6 mL
Step-by-step explanation:
We need to use the equation M1V1=M2V2. Molarity's units are in L so we need to convert the 50 ml into L (divide by 1000).
.05(.298)=(x)(.2173)
x = .068 L
to convert to mL we multiply by 1000
.068*1000=68.6 mL