A chemist needs a solution of tannic acid 70% pure. How much distilled water must he add to 5 gallons of acid which was 90% pure to obtain the 70% solution?
+118609 90% of 5 gallons = 0.9*5 = 4.5 gallons
So the original mixture contains 4.5 gallons of acid and the and 0.5 gallons of water.
Now we need to know 70% of what equals 4.5 gallons
0.70x=4.5
x=4.5/0.7
x=6.4286 gallons (correct to 4 dec places)
We already have 5 gallons
6.4285-5=1.4285 gallons
So you will need to add 1.4285 gallons of water.
+118609 90% of 5 gallons = 0.9*5 = 4.5 gallons
So the original mixture contains 4.5 gallons of acid and the and 0.5 gallons of water.
Now we need to know 70% of what equals 4.5 gallons
0.70x=4.5
x=4.5/0.7
x=6.4286 gallons (correct to 4 dec places)
We already have 5 gallons
6.4285-5=1.4285 gallons
So you will need to add 1.4285 gallons of water.
