The formation constant for the following reaction is Kf = 5.6 108 at 25°C. Ni2+(aq) + 6 NH3(aq) Ni(NH3)62+(aq) (a) Determine G0 at this temperature. kJ/mol (b) If standard-state concentrations of the reactants and products are mixed, in which direction does the reaction proceed? The reaction proceeds to the . (c) Determine G when [Ni(NH3)62+] = 0.017 M, [Ni2+] = 0.0015 M, and [NH3] = 0.0058 M. kJ/mol (d) If these concentrations are mixed, in which direction will the reaction proceed to achieve equilibrium? The reaction proceeds to the .

a. ΔG⁰ = -49.9 kJ/mol

b. The reaction proceeds towards right direction

c. ΔG = 49.5 kJ/mol

d. The reaction proceeds towards left direction

Explanation:

a. It is possible to obtain ΔG⁰ from K reaction using:

ΔG⁰ = -RT ln K

Where R is gas constant 8.314 J/molK, T is absolute temperature (273.15 +25 = 298.15K)

Replacing:

ΔG⁰ = -8.314 J/molK 298.15K ln 5.6x10⁸

ΔG⁰ = -49.9 kJ/mol

b. Reaction quotient Q, defines concentrations of substances involved in an equilibrium, when Q = Kf, the reaction is in equilibrium, when Q < Kf the reaction moves towards right direction and vice versa.

At standard-state concentrations, Q = 1, as:

Q < Kf,  the reaction proceeds towards right direction

c. ΔG = ΔG⁰ + RT ln Q

Q = [Ni(NH₃)₆²⁺] / [NH₃]⁶[Ni²⁺]

Q = 0.017M / 0.0015M⁶×0.0058M

Q = 2.6x10¹⁷

ΔG = -49.9 kJ/mol + 8.314x10⁻³ kJ/molK 298.15K ln 2.6x10¹⁷

ΔG = 49.5 kJ/mol

d. As Q > Kf, the reaction proceeds towards left direction

the answer is b because, investigating whether another species of moth also drinks tears might be interesting, but it would not directly explain why this species of moth does.

to explain why this species of moth drinks tears, the scientist could ask: "what nutrients that moths need are in elephant tears? "

the scientist could experiment with moth repellent or oter ways to keep the moths away, but that would not answer his original question.