How much will the pH change if we add 0.15 mol NaOH to 1.00 L of a buffer that contains 1.00 mol HC2H3O2 and 1.00 mol NaC2H3O2

that's what i got you can count the number of atoms

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.