Aluminum metal reacts with a solution of copper (II) nitrate. If you want to produce #5.4 * 10^24# atoms of copper, how many moles of aluminum metal are needed?

1 Answer
Jan 31, 2016

Answer:

#5.98# mols of aluminium metal are need to produce #5.4⋅10^24#
atoms of copper.

Explanation:

First we should always have a balanced chemical equation for any reaction we are calculating.

The balanced chemical equation for the reaction of aluminum metal with a solution of copper (II) nitrate is as follows:

#2 Al + 3Cu(No_3)_2 -> 2Al(No_3)_3 + 3Cu#

Secondly we should allways know the conversion between atoms and mols. 1 mol = #6.022*10^23#.

The copper has #5.4⋅10^24# atoms. We can convert this to mols by:

#(5.4*10^24)/(6.022*10^23)#

= #8.967120558# mols
= #8.97# mols

As the coefficients (the numbers at the front of the compounds in the chemical equation) are different to each other, we must change the mols.

As #3Cu# = #8.97# mols
So the aluminium must be #2Al# = #(8.97/3)*2#
#2Al# = #5.98# mol

#:.# #5.98# mols of aluminium metal are need to produce #5.4⋅10^24#
atoms of copper.