What coenzyme accepts two protons and two electrons when reduced?

Many ionic compounds and a few highly polar covalent compounds are because they completely ionize in water to create a solution filled with charged ions that can conduct an electric current.

In an exothermic reaction at equilibrium, what is the effect of lowering the temperature? a. the reaction makes more products. b. the reaction makes more reactants. c. the reaction is unchanged.

Equal volumes of h2 and o2 are placed in a balloon and then ignited. assuming that the reaction goes to completion, which gas will remain in excess? 2h2 + o2 → 2h2o a. both are in equal proportion b. oxygen c. water d. hydrogen