Precious metals are commonly measured in troy ounces. A troy ounce is equivalent to 31.1 g. How many moles are in a troy ounce of gold? How many moles are in a troy ounce of platinum? of silver?

##"Number of moles"## ##=## ##"Mass"/"Molar Mass"##

The number of moles is a numerical unit. One mole of stuff unequivocally specifies ##"Avogadro's Number"##, ##N_A##, ##6.022xx10^23##, individual items of that stuff.

Now the molar mass of gold is ##196.97*g*mol^-1##. From where did I get that mass? Did I know it from memory? From where will YOU get it if you are asked to use it?

So ##"Moles of gold"## ##=## ##(31.1*g)/(196.97*g*mol^-1)## ##=## ##?? mol##

And ##"Moles of platinum"## ##=## ##(31.1*g)/(195.08*g*mol^-1)## ##=## ##?? mol##.

And ##"Moles of silver"## ##=## ##(31.1*g)/(107.87*g*mol^-1)## ##=## ##?? mol##.

How do the individual numbers of platinum, silver, and gold compare in these quantities? Which quantity has the greatest monetary value?

On a personal level, I think only a really decadent society would continue to use such an absurd unit as a ##"troy ounce"##. For God's sake!