Question

a solution of 9% of acid is to be diluted by adding 3% of acid solution to it . the resulting to it . the resulting mixture is to be more than 5% and less than 7% of acid . if there is 460 litre of 9% solution . how many litre of 3% solution will have to be added​

Answer 1

Answer:

Solution : Let x L of 3% solution be added to 460 L of 9% solution of acid. It is given that acid content in the resulting mixture must be more than 5% but less than 7% acid. Hence, the number of litres of the 3% solution of acid must be more than 230 L and less than 920 L.

Answer 2

Step-by-step explanation:

If you add x litres of 3% solution you have added 0.03 litres* of boric acid to 0.09 litres of boric acid. So 1+x litres contains 0.12 litres of boric acid. Therefore the concentration is 0.12/(1+x). If this is 0.05 then 1+x=12/5 and x=7/5. If it is 0.07 then 1+x=12/7 and x=5/7.

So you need to add between 460*7/5 litres and 460*5/7 litres.

*Probably not litres, it depends how the concentration is measured. It’s probably moles or something,