Question

How much pure alcohol must be added to 4 hundred ml of a 15 percent solution To make it strength 32%

Answer 1

Answer:

100 ml alcohol

Step-by-step explanation:

Let the volume of alcohol be x ml

Initial concentration =15 %

So, Initial amount of alcohol in the solution will be = 15 × 400 = 60 ml

100

To make the strength of the solution 32%,we will keep the amount of water constant and on adding pure ,alcohol ,the volume of the solution increases to 400 + x.

According to question

x + 60 = 32

400+x 100

=>100 x +6000 = 12800 + 32 x

=> 100x - 32x = 12800 - 6000

=>68x = 6800

=>x = 100

So, the amount of pure alcohol to be added = 100 ml

Answer 2

Hi mate,

Solution :

=> Volume of alcohol in 400 ml solution

➾ 0.15 × 400 ml

=> Volume of alcohol in 400 ml solution

➾ 60 ml

=> Volume of others liquid

➾ 340 ml

=> Let x ml of alcohol is added to make it 32% strong

=> Then, volume of alcohol

➾ 60+x ml

=> Volume of other liquid

➾ 340 ml

=> Volume of solution

➾ 400 + x ml

➾ 0.32 × (400 + x) = 60 + x

➾ 128 + 0.32x = 60 + x

➾ 0.68x = 68

➾ 68x = 6800

➾ x = 100 ml ...

Answer : 100 ml pure alcohol must be added to 400ml of a 15% solution to make it's strength 32%

i hope it helps you