If given: A 1.4470g sample of an oxide of gold was reduced with ethane to 1.2900g of gold metal. What is the simple formula of the original gold oxide?

Answer 1

How many moles of gold is 1.29g? How many moles of O is in (1.447-1.29)g of oxygen?

divide the lower number of moles (gold, or O) into the larger, that is the mole ratio of the elements in the formula.