Which best describes the heat that you can feel on the engine of a running car? the heat is unusable and absorbed by the engine. the heat is usable and absorbed by the engine. the heat is unusable and lost to the surroundings. the heat is usable and lost to the surroundin

Answer is: The heat is unusable and lost to the surroundings.

Gasoline is a mixture  of many different hydrocarbons: alkanes (paraffins), cycloalkanes  and alkenes (olefins).

Balanced chemical reaction of gasoline combustion:

C₈H₁₈ + 25/2O₂ → 8CO₂ + 9H₂O + energy.

One part of energy produced in combustion of gasoline is used for car ungine (kinetic energy) and other part of that energy (in form of heat) is lost to the surronding and engine does not use it.

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.