Which is an example of a free expansion of a gas? the expansion of a gas due to a chemical reaction among its particles the uncontrolled expansion of a gas into a vacuum the expansion of a gas as it performs work on its container the expansion of a gas as heat is transfered to it at constant pressure

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.