He built his work upon JJ Thompson, a scientist.
Answer:
She will need to add 5.6 cups of water
Explanation:
Hi there!
Marta has to dilute the citric acid to 5%.
The dilution factor will be 12%/ 5% = 2.4. Then, Marta will need to dilute the citric acid 2.4 times. If she has 4 cups of the solution, she will need to add water until she completes a volume of (4 cups ·2.4) 9.6 cups to reach the desired concentration.
Then, she will need to add 9.6 - 4 cups water = 5.6 cups of water
Another way to solve this is by using the fact that the mass of citric acid in the concentrated and diluted solution is the same. Then:
mass citric acid concentrated solution = mass citric acid in dilute solution
mass of citric acid = concentration · volume
Then:
initial concentration · volume = final concentration · volume
12% · 4 cups = 5% · volume
volume = 12% · 4 cups / 5% = 9.6 cups
The final volume of the solution at 5% will be 9.6 cups. So Marta will need 9.6 cups - 4 cups = 5.6 cups water
