Based in the data provided, the percentage by mass of K2SO4 is 60.55 %.
<h3>What is the mass of K2SO4 in the mixture?</h3>
The mass of K2SO4 in the mixture is obtained from the data given as follows:
Total mass of sample = 0.649 g
Let the mass of K2SO4 in the mixture be X g
Mass (NH4)SO4 = (0.649 - X )g
Moles of K2SO4 = X g/174.25 g/mol
= 0.00574X mol
Moles of (NH4)2SO4 = (0.649 - X)g / 132.13 g/mol
= (0.00491 - 0.00757X) mol
Total number of moles SO42- ions precipitated = 0.00574X mol + (0.00491 - 0.00757X)mol
= (0.00491-0.00183X) mol
Mole ratio of SO42- ions to Ba2+ ions = 1:1
Thus, moles of Ba2+ ions = (0.00491 - 0.00183X)mol
Moles of BaSO4 precipitated = 0.977 g/233.38 g/mol = 0.00419 moles
1 mole of BaSO4 produces 1 mole of Ba2+ ions
Therefore,
(0.00491 - 0.00183X) mol = 0.00419mol
0.00183X = 0.00491 - 0.00419mol
0.00183X = 0.00072
X = 0.00072/0.00183 = 0.393 g
Mass of K2SO4 = 0.393 g
Percentage by mass of K2SO4 = (0.393/0.649) × 100
Percentage by mass of K2SO4 = 60.55 %
Learn more about percentage by mass at: brainly.com/question/26150306
