posted by jill .
In the lab, 20.0 g of sodium hydroxide is added to a beaker giving it a total mass of 128.4 g. Sulfuric acid is added until all of the sodium hydroxide reacts. After heating, the total mass of the beaker and the dry compound is 142.3 g. Caculate the percent yeild.
2NaOH + H2SO4 ==> Na2SO4 + 2H2O
Convert 20.0 g NaOH to mols NaOH.
Convert mols NaOH to mols Na2SO4 using the coefficients in the balanced equation above.
Convert mols Na2SO4 to grams Na2SO4 using mols x molar mass = grams. This value is the theoretical yield (in grams)
%yield = (A/T)*100
where A = actual mass Na2SO4 collected.
T = theoretical yield.
Post your work if you get stuck and need further assistance.