11. A 120 milliliter (mL) solution contains a mixture of water and acid. The acid makes up 40% of the solution. How many mL of water make up the solution?
Answer: C
72 mL of water make up the solution.
In a 120 mL solution where 40% is acid, the amount of acid can be calculated as 40% of 120 mL, which is 48 mL. Therefore, the volume of water is the remaining part of the solution, which is 120 mL - 48 mL = 72 mL.
A) 40 mL
40 mL of water would mean there is only 80 mL of acid in the solution, which contradicts the given information that acid makes up 40% of the 120 mL solution. This option is incorrect.
B) 60 mL
If there were 60 mL of water, then the amount of acid would have to be 120 mL - 60 mL = 60 mL. This would mean that the acid constitutes 50% of the total solution, not 40%. Therefore, this option is also incorrect.
C) 72 mL
This option correctly accounts for the total volume of 120 mL. Since 40% of the solution is acid, which equals 48 mL, subtracting this from 120 mL gives us 72 mL of water. Thus, this option is correct.
D) 48 mL
Having 48 mL of water would suggest that the acid makes up the remaining 72 mL, which would represent 60% of the solution. This is inconsistent with the information given that the acid comprises only 40% of the solution. Hence, this option is incorrect.
Conclusion
The correct answer of 72 mL aligns with the calculation derived from the percentage composition of the solution. All other options fail to accurately reflect the ratio of acid to water based on the provided percentage, demonstrating a misunderstanding of the solution's total volume and its components.