How many formula units of #CuCl_2# are present in a #12.53*g# mass of the salt?

1 Answer
anor277
Feb 15, 2018

Well what is the formula mass of cupric chloride....?

Explanation:

The anhydrous salt has a formula mass of #134.45* g*mol^-1 #. How did I get this?

And so we take the QUOTIENT....#"mass"/"formula mass"#...

...#(12.53*cancelg)/(134.45* cancelg*mol^-1)=0.0932*mol#

And so how does this molar quantity help us? Well we know that BY DEFINITION one mole specifies #"Avogadro's number"# of formula units....where .........

#N_A-="Avocado number"=6.022xx10^23*mol^-1#

And so we take the product...

#"molar quantity"xx"Avogadro's number"#

#0.0932*molxx6.022xx10^23*mol^-1-=5.62xx10^22*"formula units"#

...and we are careful to speak of #"formula units"# of #CuCl_2#. How many copper atoms, and how many chlorine atoms are in this quantity?

Related questions
Impact of this question
473 views around the world
You can reuse this answer
Creative Commons License