Question

50.0 mL of a 1.80 M solution is diluted to a volume of 278 mL. A 139-mL portion of that solution is diluted using 185 mL of water. What is the final concentration?

Answer 1

whr r u stuck

Answer 2

this would be an easy one cause you use one equation...
c1V1 = c2V2
so in first part you have c1V1 and V2 and when you rearange the equation you get:
c2= c1V1/V2
now your c2 is new c1 and you just rearange the equation again with addition of water to new volume of water which is added...