A sample of a mixture containing only sodium chloride (NaCl) and potassium chloride (KCl) has a total mass of 4.000g. When this sample is dissolved in water and excess silver nitrate is added a white precipitate (AgCl) forms. After filtration and drying, this precipitate had a mass of 8.5904g. Calculate the mass percent of each component in the mixture.
2006-11-12 14:06:36 · 1 answers · asked by azncrazygurl520 1 in Science & Mathematics ➔ Chemistry
NaCl + AgNO3 -> NaNO3 + AgCl
x x
KCl + AgNO3 -> KNO3 + AgCl
y y
let x be the moles of NaCl and y be the moles of KCl
we have
58.5x + 74.5y = 4
143.5 (x+y) = 8.5904
=> x = 0.028 y=0.031
the mass percent of each substance
NaCl = 58.5*0.028 / 4 *100 = 43 %
KCl = 74.5 * 0.031 / 4 *100 = 57 %
2006-11-12 14:17:33 · answer #1 · answered by James Chan 4 · 0⤊ 0⤋