One method for removing hydrogen sulfide impurities from natural gas is by its reaction with oxygen at high temperatures to form sulfur and water vapor. After balancing the following equation, determine the coefficient in front of the reactant O2. H2S(g) + O2(g) → S8(l) + H2O(g) Group of answer choices

Which of the following statements is true? a. most heat energy is easily recovered and used for useful actions. b. friction causes molecules to vibrate more slowly. burning air and gasoline in an c. engine changes chemical energy into mechanical energy. it is impossible to d. change mechanical energy into mechanical energy.