Double displacement reactions are often defined by which of the following? a) use of oxygen as a reactant b) formation of a precipitate c) release of light d) breakdown of only one compound

The answer to your question is: b) formation of a precipitate.

I hope this helps!

The answer is B. Formation of a precipitate

it can be icreased by increasing 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.