Question

20% ethanol solution is mixed with another ethanol solution, say, s of unknown concentration in the proportion 1:3 by volume. This mixture is then mixed with an equal volume of 20% ethanol solution. If the resultant mixture is a 31.25% ethanol solution, then the unknown concentration of s is

Answer 1

too critical for anyone on this planet

Answer 2

Answer:

(20%of 1 part)+(S%of 3 parts)+(20%of 4 parts) = (31.25% of 8 parts)

20+3S+80 =250

3S=150

so,S=50

S%=50%(Answer)