Suppose that a solution was prepared by dissolving 25.0 g of sugar into 100g water. The percent by mass would be:

To calculate the percent by mass of the sugar in the solution, you need to follow these steps:

1. First, find the total mass of the solution. This is the sum of the mass of the sugar and the mass of the water. So, 25.0 g (sugar) + 100 g (water) = 125.0 g (total mass of the solution).

2. Next, calculate the percent by mass. This is the mass of the sugar divided by the total mass of the solution, multiplied by 100%. So, (25.0 g / 125.0 g) * 100% = 20%.

Therefore, the percent by mass of the sugar in the solution is 20%.