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Answer 1 · 2015-10-19T09:29:06

$"9.3 moles"$

To find how many moles you get in one kilogram of silver you need to use silver's molar mass.

A substance's molar mass tells you what the exact mass of one mole of that substance is.

In silver's case, its molar mass is listed as $"107.8682 g/mol"$ . This tells you that one mole of silver has a mass of $"107.8682 g"$ .

$"1 mole of Ag" -> "107.8682 g"$

All you have to do now is figure out how many moles would fit, so to speak, in one kilogram. Convert this mass from kilograms to grams first

$1color(red)(cancel(color(black)("kg"))) * "1000 g"/(1color(red)(cancel(color(black)("kg")))) = "1000 g"$

This means that you have

$1000color(red)(cancel(color(black)("g Ag"))) * "1 mole Ag"/(107.8682 color(red)(cancel(color(black)("g Ag")))) = "9.2706 moles Ag"$

of silver in one kilogram of silver.

I'll round this number off to two sig figs to get

$n = color(green)("9.3 moles Ag")$