posted by Anonymous .
calculate the mass percent of sand, sodium chloride and copper(ll) sulfate in a sample that yields: mass of sample= 14.088g, mass of sand=0.2255g, mass of copper(ll)oxide = 0.1994g (assume 100% yield for each of the copper(ll) reactions)
CuSO4(aq) + 2NaOH(aq) --> Cu(OH)2(s) + Na2SO4(aq)
Cu(OH)2---> CuO(s) +H2O
Would you please check your post. You need to explain what you're doing. Where did the NaCl come from? What did you do with the excess NaOH?