The mass percent of potassium chloride is 1.386%
calculation
mass percent = actual mass/ Theoretical mass x 100
Actual mass = 9.35 g
Theoretical mass is calculated as below
Step 1 : write the equation for reaction
KCl + H₂O → KOH + HCl
Step 2: find the moles of H₂O
moles = mass÷ molar mass
The molar mass of H₂O = (2 x1 ) +(16) = 18 g/mol
moles is therefore = 162.98 g÷ 18 g/mol =9.054 moles
Step 3: use the mole ratio to determine the moles of KCl
KCl: H₂O is 1:1 therefore the moles of KCl is also = 9.054 moles
Step 4: find the theoretical mass of KCl
mass = moles x molar mass
from periodic table the molar mass of KCl = 39 +35.5 =74.5 g/mol
mass = 9.054 moles x 74.5 g/mol =674.5 g
Theoretical mass is therefore = 9.35 g/ 674.5 g x 100 = 1.386%
