Aluminum reacts with HCl to produce aluminum chloride and hydrogen gas. Write a
balanced equation for the reaction and calculate the number of moles of HCl required to
react with 0.87 moles of Al.

it takes on an electronical energy

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.