Steochemistry

Question

a student started with 0.3295 g of cupper(ii) oxide product was found to be 0.5723 g , and that of filter paper alone was 0.2568 g .calculate the percent yield of cupper(ii) 

Answer 1

A little more information is needed.  What is the reaction?  Did you start with 0.3295 g of CuO and heat it to get Cu and O2?  Was the 0.5723 g the mass of product + filter paper?  Maybe you should resubmit the question exactly as given to you.