Question

If there are 7.44 x 10(23) atoms of gold, how many moles of gold are there?

Reviewing for a final. Went through some old quizzes to work on stuff I got wrong, and all my teacher did be circle it, and I don't understand what I did wrong.

Answer 1

`=1.24molAu`

Explanation:

1. Given then `eta "atom "Au=7.44xx10^23`, this value can be translated to `etaAu` through molar conversion.
2. Knowing the mole relationship as shown below, is your equivalence statement. This is actually the Avogadro's number `(N_A)` also known as mole; thus,
   `1molAu=6.02x10^23 (N_A)"atoms "Au`
3. From the given equivalence statement, two (2) conversion factors can be derived.
   `(1molAu)/(6.02xx10^23"atoms"Au) or (6.02xx10^23"atoms"Au)/(1molAu)`
4. Choose the right conversion factor making sure that the unwanted unit are cancelled leaving the desired one.
   `=7.44xx10^23cancel("atoms"Au)xx(1molAu)/(6.02xx10^23cancel("atoms"Au))`
   `=(7.44xx10^23molAu)/(6.02xx10^23)`
   `=1.24molAu`