1) Given the following thermochemical reaction and thermodynamic data, find Gibbs Free Energy, ΔG, and determine if the reaction is spontaneous or non-spontaneous at 25 °C?
N2(g) + 3H2(g) → 2NH3(g) ΔH = -91.8 kJ
ΔS[N2] = 191 J / mol · K, ΔS[H2] = 131 J / mol · K, and ΔS[NH3] = 193 J / mol · K
a.98.3 kJ; Non-Spontaneous
b.-98.3 kJ; Spontaneous
c.32.7 kJ; Non-Spontaneous
d.ΔG = -32.7 kJ; Spontaneous
2) What is the oxidation number for selenium in the Selenate Ion, SeO4-2?
3) Given the following electrochemical reaction, identify the reducing agent.
2Al(s) + 3F2(g) → 2AlF3(s)
Aluminum Fluoride (AlF3)
4) Calculate the cell potential, E°cell, for the following electrochemical reaction.
Cu(s) + I2(g) → Cu+2(aq) + 2I-1(aq) E = ?
∆S = (∆S of product ) - (∆S of reactant)
= (2× 193) - (191+ 3×131)
= - 198 J/ mol K
= - 0.198 kJ / mol K
T = 25+273 = 298 K
So , putting the values in above equation,,
Negative sign indicates that , it is a spontaneous reaction.
So, option (d) is the correct answer.
Answer)2. Option (a) is the correct answer.
Se + (-2)×4 = -2
Se = +6
Answer)3. Option (b) is the correct answer.
Aluminium is the reducing agent, because it is oxidized in the reaction and reduce the fluorine .
Get Answers For Free
Most questions answered within 1 hours.