How do you find the formula units in 2.6 g of lithium bromide?

1 Answer
Feb 2, 2017

#"Number of formula units of LiBr"# #~=# #2xx10^22#

Explanation:

#"Number of formula units of LiBr"="Mass"/"Molar mass of LiBr"xxN_A#

where #N_A="Avogadro's number"-=6.022xx10^23*mol^-1#

And thus, #(2.6*cancelg)/(86.84*cancelg*cancel(mol^-1))xx6.022xx10^23*cancel(mol^-1)=??#

Since all the units cancel out, we get the answer as a number, as required.