Question

1)Calculate K at 25 C for the reaction below (i.e. in question 7).

Correct answer is 5.6E27 +/- 0.3E27, but I am unable to figure out how to get it.

2) Calculate ΔGo for the reaction below (questions 7)

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Question 7

Under standard conditions, what product(s) form when Cl2 gas is bubbled into a solution of NaI

a) no reaction
b) I2 (Correct Answer)
c) Na+
d) Na

Cl2 + 2e- -> 2Cl 1.358V

2I -> I2 + 2e -0.535V

1.358V - 0.535 V = 0.823V (Use this to solve question asked)

Since E Cell is 0.823V (positive) I2 will be produced.

Answer 1

The reaction involved is

$Cl_{2}\: + 2NaI \: \rightarrow I_{2} \: +2NaCl$

so iodine gas is released.

given Ecell = + 0.893V

n= number of electrons involved = 2

T = 25^oC = 323K

then

$\Delta G = -nFE_{cell}$

$\Delta G = -2X96500X0.893 =\: - 172349joules =\: -172.34kj$

and K is given by

$log K = \: - \frac{\Delta G}{2.303RT}$

$log K = \: - \frac{\left ( -172349 \right )}{2.303X8.314X 298}= +30.2$