What is the amount of gold present in 15.5g of a pure gold ring? (Au=197)

.0787 moles

Explanation:

I'm assuming you mean moles of gold present as the "amount."

This is a moles to moles calculation, so we set it up as such:

*Note that 15.5g Au is given to us, and 197 g / mol of Au is gold's molar mass.

15.5g Au * (1 mol Au / 197 g Au) = ?

We can evaluate the equation to get 15.5 / 197 to get .0787 moles of Au.