posted by Lauren .
Washing soda is added to hard water to allow soap to lather.
A certain brand of washing soda contains partially hydrated
sodium carbonate solid. A 0.300 g sample completely reacts
with 20.0 mL of 0.250 M hydrochloric acid.
a What mass of sodium carbonate was present?
b Calculate the percentage by mass of sodium carbonate in
the washing soda.
Na2CO3 + 2HCl ==> 2NaCl + H2O + CO2
mols HCl used = L x M = 0.020 L x 0.250 M = ??
mols Na2CO3 = ?? mols HCl x 1/2 = ??
g Na2CO3 = mols x molar mass Na2CO3 = ??
%Na2CO3 = (grams Na2CO3/0.300) * 100 = ?