chemistry conversion help needed please.....

Question

13.5 g of Aluminium when changes to Al³⁺  ion , in solution , will be :

 

•  9.0 X 10²³   electrons 
• 3.01 X 10²³  electrons
• 6.023 X 10²³ electrons
• 18.0  X 10²³ electrons

Answer 1

First determine the number of moles of aluminum using the molar mass from the periodic table:

 

(13.5 g)/(26.98 g/mol) = 0.500 mol Al

 

Now determine how many atoms of Al you have by multiplying by Avogadro's number:

 

(0.500 mol Al)* (6.022 x 10²³ atoms/mol)= 3.011 x 10²³ atoms Al.

 

For every oxidation of an Aluminum atom, 3 electrons will go off into solution, so simply multiply this number by 3:

 

3.011 x 10²³ atoms Al * 3 e-/atom = 9.0 x 10²³ electrons