<u>Answer:</u> The molality of magnesium chloride is 1.58 m
<u>Explanation:</u>
To calculate the molality of solution, we use the equation:
Where,
= Given mass of solute (magnesium chloride) = 75.0
= Molar mass of solute (magnesium chloride) = 95.21 g/mol
= Mass of solvent = 500.0 g
Putting values in above equation, we get:
Hence, the molality of magnesium chloride is 1.58 m
Answer:
Fe =52.2%, O = 44.9%, H = 2.81%
Explanation:
Percentage composition is also known as percentage by mass.
First, find the Mr of the compound.
Mr of Fe(OH)₃ = 55.8 + (16 × 3) + (1 × 3)
= 106.8
Now Divide the mass of the element, as per the compound, by the Mr of the compound found and times that by 100.
% composition of Fe = × 100 = 52.2%
% composition of O = × 100 = 44.9%
[There are 3 oxygen atoms in the compound Fe(OH)₃, so we will multiply the atomic mass of oxygen with the number of atoms in the compound: 16×3 ]
% composition of H = × 100 = 2.81%
[There are 3 hydrogen atoms in the compound Fe(OH)₃, so we will multiply the atomic mass of hydrogen with the number of atoms in the compound: 1×3 ]