Answer:
The amount of water must be added to this task = 60
![cm^(3)](https://img.qammunity.org/2021/formulas/chemistry/middle-school/lvic7xkhag35w5dw9wmgq285feeh6rj8ut.png)
Explanation:
Let amount of water added = x
![cm^(3)](https://img.qammunity.org/2021/formulas/chemistry/middle-school/lvic7xkhag35w5dw9wmgq285feeh6rj8ut.png)
Then from the given conditions
A chemist would like to dilute a 90-cc solution that is 5% acid to one that is 3% acid. So
90 (0.05) = 0.03 ( 90 + x )
4.5 = 2.7 + 0.03 x
0.03 x = 1.8
x = 60
![cm^(3)](https://img.qammunity.org/2021/formulas/chemistry/middle-school/lvic7xkhag35w5dw9wmgq285feeh6rj8ut.png)
Therefore the amount of water must be added to this task = 60
![cm^(3)](https://img.qammunity.org/2021/formulas/chemistry/middle-school/lvic7xkhag35w5dw9wmgq285feeh6rj8ut.png)