Question

Cinnabar is a natural mercury(II) sulfide, HgS, found near volcanic rocks and hot springs. It is the only important source of mercury, which has many uses, including dental amalgams, thermometers, and mercury vapor lamps. Mercury is formed in the following endothermic reaction when mercury(II) sulfide is heated. Consider a system in which a sample of HgS in a closed container is heated with a Bunsen burner flame. 8HgS(s) → 8Hg(l ) + S8(s)

a. Describe the changes in particle motion as heat is transferred from the hot gases of the Bunsen burner flame to the container to the HgS(s).

b. In general terms, explain why energy is absorbed in the reaction.

c. Into what form of energy is the heat energy converted for this reaction?

Answer 1

As heat is transferred , the reactino is endothermic, equilibrium gets shifted to the reactant side and as a results less prodcut is formed.

b. Becuae for creating S8 molecules molre energy is required. Enthalpy change is defined

Energy required to break bonds- energy required to form bonds.

more energy is required to create bonds in S8 than the energy stored in HgS molecules is leading to endothermiciy of reaction.

c. Heat energy is converted Into chemical energy.