If 45.8 grams of MgO are dissolved in 205 grams of water, what is the concentration of the solution in percent by mass?
To find the concentration of the solution in percent by mass, we need to determine the mass of MgO in the solution and then calculate the percentage of that mass in relation to the total mass of the solution.
First, we need to find the mass of MgO in the solution. Since we are given that 45.8 grams of MgO are dissolved, the mass of MgO in the solution is 45.8 grams.
Next, we need to calculate the total mass of the solution. This is the sum of the mass of MgO and the mass of water. We are given that the mass of water is 205 grams. So, the total mass of the solution is 45.8 grams (MgO) + 205 grams (water) = 250.8 grams.
Finally, we can calculate the concentration of the solution in percent by mass. This is done by dividing the mass of MgO by the total mass of the solution and multiplying by 100. So, the concentration is (45.8 grams / 250.8 grams) * 100 = 18.27%.
Therefore, the concentration of the solution in percent by mass is 18.27%.