Fun fact

Recycling one glass jar saves enough energy to watch television for 3 hours! ™

Can someone me with questions 12 and 13 plz.

Calculate - analysis of compound composed of iron and oxygen yields 174.86 of fe and 75.14g of o. what is the empirical formula for this compound?

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.