Answer:
Since we are adding more water to an alcohol solution,
the volume of alcohol in the alcohol will be the same but the volume percent of alcohol will decrease
<u>Initial Volume of Alcohol in the solution:</u>
We are given that 70% of the 2.1 mL solution is alcohol
So, Finding 70% of 2.1
70/100 * 2.1 = 1.470 mL alcohol
<u>Volume of Water in the Solution:</u>
In our initial solution, we have (2.1 - 1.47) mL water
and we add an additional 6.7 mL water in the solution
Hence,
the total amount of water in the solution = (2.1- 1.47) + 6.7
Total amount of water in the solution = 0.63 + 6.7
Total amount of water in the solution = 7.33 mL
Volume of the final solution = 8.8mL
<u>Percent Alcohol in the new mixture:</u>
Now that we know the volume of alcohol and the volume of water in our mixture, we can now find the percent composition of alcohol
Percent of alcohol (%v/v) = Amount of alcohol / 100mL of solution
Percent of alcohol = (1.47 / 8.8) * 100
Percent of alcohol = 0.167 * 100
Percent of alcohol = 16.7
Therefore, in a 100mL solution, we will have 16.7 mL alcohol