posted by Anonymous .
Copper (2) fluoride contains 37.42% F by mass. calculate the mass of fluorine (in grams) contained in 35.6 g of copper(2) fluoride.
37.42% of 35.6 g = ??
You had 35.6 g CuF2 to start. Only part of that was F. How can you have more F than you started with? Did you multiply by percent OR did you convert percent to a decimal before multiplying. You should have converted percent to a decimal.