Work out the ##M_r## by adding up the ##A_r## values as they occur in the formula, then work out the % contribution each element makes.
Work out the ##M_r## by adding up the ##A_r## values as they occur in the formula.
I’ll use approximate values:
##A_rNa=23##
##A_rH=1##
##A_rS=32##
##A_rO=16##
##M_r## of ##NaHSO_4##:
##=23+1+32+(4xx16)=120##
Then work out the % contribution each element makes:
%##Na=(23)/(120)xx100=19.16##
%##H=(1)/(120)xx100=0.833##
%##S=(32)/(120)xx100=26.66##
%##O=(64)/(120)xx100=53.33##
