Question

In an 8grams solution of water and alcohol, the ratio by mass of water to alcohol is3 to 1. If 12 grams of a solution consisting of 2 grams water for each gram of alcohol is added to the 8 grams solution, what fraction by mass of the new solution is alcohol?

Answer 1

In 8 gram sloutn, W : A = 3 : 1, so water 6 gram and alcohol 2 gram..

In 12 gram solution..
2 gram water in each gram of alcohol... so ratio 2: 1, so water 8 gram and alcohol 4 gram..

If they are mixed, than what will be the complete ratio, (if this the question :-p)

20 gram contains = 14 gram water, and 6 gram of alcohol..

So ratio W: A = 14: 6 = 7: 3...

for every 3 gram of alcohol, 7 gram of water is added..