Final answer:
To find out how much water was used to create a sugar solution with a concentration of 45 g/100 ml and 135 g of sugar, the total solution volume must be calculated first (300 ml). Then, the volume of water can be deduced by subtracting the sugar portion - resulting in 165 ml of water used.
Step-by-step explanation:
The student's question involves determining the amount of water used in making a sugar solution with a known concentration. Given the concentration of sugar, we can calculate the total volume of the solution and then find out how much water was added.
The concentration of sugar in the solution is 45 g/100 ml. This means that for every 100 ml of solution, there is 45 g of sugar. If the student has used 135 g of sugar, then first we need to determine the volume of the solution that contains this amount of sugar:
135 g sugar x (100 ml solution / 45 g sugar) = 300 ml solution.
This indicates that the total volume of the solution is 300 ml. Since we know the total grams of sugar, we can subtract this from the total grams of the solution to obtain the grams of water. However, since water's density is approximately 1 g/ml, we can assume for this calculation that the grams and milliliters of water are equal. Therefore, 300 ml of the solution minus the volume occupied by sugar gives us:
300 ml solution - (135 g sugar x (1 ml water / 1 g sugar)) = 165 ml water.
Hence, 165 ml of water was used to make the sugar solution.