100 grams of phosphoric acid should be produced in a laboratory. Calculate how many grams of a reactant you have to start a reaction with, if the percentage yield is 52.5%. Please show all work it would be greatly appreciated. I'm desperate and have been stuck for 2-3 hours. Plz someone help.

i do not get it   at all

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.

c. electrical charges of ionic bonds.