Need answered asap for test if a chemical change requires energy, which of the following could be the source of the energy? select one: a. settling the mixture for 20 minutes b. adding more substance to the observed material c. measuring mass from a beam balance d. heating with a flame

Liquid ammonia is produced at high temperatures and under great pressure in a tank by passing a mixture of nitrogen gas and hydrogen gas over an iron catalyst. the reaction is represented by the following equation. n2(g) + 3h2(g) → 2nh3(g) changing all but one experimental condition will affect the amount of ammonia produced. that condition is a) increasing the concentration of both reactants b) changing the temperature within the tank c) decreasing the pressure within the tank. d) increasing only the amount of nitrogen present.