200. g of a solvent is available, how many grams of a solute should be weighed out to make a 15.0% solution by mass?
What's the definition of mass percent?
% = (mass solute/100 g solution)*100.
mass solute = x
mass solution = 200 g solvent + x g solute = 200+x
Substitute and solve for x.
(x/x+200)*100 = 15
x=??
still not making sense because answers are
a. 30.0
b. 35.3
c. 15.0
d. 28.9
Then you made a math error because the correct answer is listed.
To determine how many grams of a solute should be weighed out, we need to understand what a 15.0% solution by mass means.
A 15.0% solution by mass indicates that the solute's mass is 15.0% of the total mass of the solution. In other words, the mass of the solute is 15.0% of the sum of the solute's mass and the solvent's mass.
Let's calculate the required mass of the solute:
1. Convert 15.0% to decimal form by dividing it by 100: 15.0% / 100 = 0.150
2. The total mass of the solution will be the sum of the mass of the solute and the solvent: total mass = mass of solute + mass of solvent.
3. Since we have 200. g of solvent, we can substitute that value into the equation: total mass = mass of solute + 200. g
4. Knowing that the mass of the solute should be 0.150 times the total mass, we can set up the equation: mass of solute = 0.150 * (mass of solute + 200. g).
Now, let's solve the equation to find the mass of the solute:
mass of solute = 0.150 * (mass of solute + 200. g)
mass of solute = 0.150 * mass of solute + 0.150 * 200. g
mass of solute - 0.150 * mass of solute = 0.150 * 200. g
0.850 * mass of solute = 30. g
mass of solute = 30. g / 0.850 ≈ 35.29 g
Therefore, approximately 35.29 grams of the solute should be weighed out to make a 15.0% solution by mass.