Question

What is the percentage by mass of solution formed by dissolving 36.0 grams of HCl in 98.0 grams of water?

Answer 1

Answer:

The percentage by mass of the solution is 26.86%.

Explanation:

Mass of hydrochloric acid = 36.0 g

Mass of water = 98.0 g

Solution = HCl+ Water

Mass of the solution =  36.0g + 98.0 g = 134 g

mAss percentage of the solution:

$\frac{\text{Mass of solute}}{\text{Mass of the solution}}\times 100$

$\frac{36 g}{134 g}\times 100=26.86\%$

The percentage by mass of the solution is 26.86%.

Answer 2

Convert HCl and H2O to mols.

36.0g HCl = 0.987mols HCl

98.0g H2O = 5.44mols H2O

According to the stoichiometric ratio of HCl,
you have 0.987mols of H and 0.987mols of Cl.

According to the stoichiometric ratio of H20, you have 10.88mols of H and 5.44mols of O.

Summing them:
11.867 mols H
0.987 mols Cl
5.44 mols O

Convert each back to grams and divide by total mass and multiply by 100 to determine percentage by mass.

11.867mol H = 11.96g H
0.987mols Cl = 34.99g Cl
5.44mols O = 87.03g O

11.96/(36.0+98.0)(100) = 8.93% H
34.99/(36.0+98.0)(100) = 26.11% Cl
87.03/(36.0+98.0)(100) = 64.96% O