What is the mass of zinc

Question

I’m doing the penny lab and the before mass of the post 1982 penny is 2.54g and the after mass is .23g and now I need to find the mass of zinc

Answer 1

Not sure what you did to your penny in the lab, but I'm guessing you removed the Zn and are left with 0.23 g. So, to find the mass of Zn, you would have 2.54 g - 0.23 g = 2.31 g of Zn. This corresponds to 90.9% Zn. Interestingly, after 1982, pennies were made to contain ~98% Zn, so your value is close, but off a bit.