What is the percentage composition of a soap #(C_17H_35COONa)#?

1 Answer
Feb 20, 2016

We solve for individual elemental percentages:

Explanation:

The molecular mass of sodium stearate is #306.46# #g*mol^-1#.

#%C# #=# #(18xx12.011*g*mol^-1)/(306.46*g*mol^-1) xx 100%##= # #??#

#%H# #=# #(35xx1.00794*g*mol^-1)/(306.46*g*mol^-1) xx 100%##= # #??#

#%Na# #=# #(1xx22.99*g*mol^-1)/(306.46*g*mol^-1) xx 100%##= # #??#

#%O# #=# #(2xx15.999*g*mol^-1)/(306.46*g*mol^-1) xx 100%##= # #??#

Should the elemental percentages sum to 100%? Why?