Which reactions are endothermic? (select all that apply.) a. h2(g) + ½o2(g) h2o(aq), h = -57.83 kcal/mole b. ½ n2(g) + ½o2(g) no(g), h = +21.6 kcal/mole c. ½n2(g) + o2(g) + 8.1 kcal no2(g) d. ½n2(g) + 3/2 h2(g) nh3(g) + 11.0 kcal/mole e. nh3(g) ½n2(g) + 3/2 h2(g), h = +11.0 kcal/mole

Reactions B,C,D and E are endothermic since the enthalpy change for each is positive. When endothermic reactions occur, they absorb energy from the environment thus the overall energy change becomes positive( they are all preceded by a plus sighn, +)

Answer is: the equilibrium  shifts toward the reactants, to the left side of chemical reaction.it is because lead(ii) nitrate dissociates in water: pb(no₃)₂ → pb²⁺(aq) + 2no₃⁻(aq).according to lechatelier's principle, the position of equilibrium moves to counteract thechange (more lead cations, common ion), the position of equilibrium will move so that the concentration ofproducts decrease and concentration of reactants of chemical reaction increase.read more on -

Where is the illustration?