Question

You need a 30% alcohol solution. On hand, you have a 200 mL of a 10% alcohol mixture. You also have 55% alcohol mixture. How much of the 55% mixture will you need to add to obtain the desired solution?

Answer 1

Answer: 160 ml

Step-by-step explanation:

The expression used will be :

`C_1V_1+C_2V_2=C_3V_3`

where,

`C_1` = concentration of Ist alcohol solution= 10%

`C_2` = concentration of 2nd alcohol solution= 55%

`V_1` = volume of Ist alcohol solution = 200 ml

`V_2` = volume of 2nd alcohol solution= v ml

`C_3` = concentration of resulting alcohol solution= 30%

`V_2` = volume of resulting alcohol solution= (v+200) ml

Now put all the given values in the above law, we get the volume of added.

`(10* 200)+(55* v)=(30* (v+200)ml)`

By solving the terms, we get :

`v=160ml`

Therefore, the volume of 55% mixture needed to be added to obtain the desired solution is 160 ml.