[I⁻] = 0.0352M
Based on the equilibrium:
I₃⁻(aq) ⇄ I₂(aq) + I⁻(aq)
Kc is defined as:
Kc = 0.25 = [I₂] [I⁻] / [I₃⁻]
The system reaches the equilbrium when the ratio [I₂] [I⁻] / [I₃⁻] is equal to 0.25
In the beginning, you add 0.0401M of both [I₂] [I⁻]. When the reaction reach the equilibrium, xM of both [I₂] [I⁻] is consumed producing xM of [I₃⁻]. That is written as:
[I₃⁻] = X
[I₂] = 0.0401M - X
[I⁻] = 0.0401M - X
X is known as reaction coordinate.
Replacing in Kc:
0.25 = [I₂] [I⁻] / [I₃⁻]
0.25 = [0.0401M - X] [0.0401M - X] / [X]
0.25X = 0.00160801 - 0.0802X + X²
0 = 0.00160801 - 0.3302X + X²
Solving for X:
X = 0.0049M → Right solution
X = 0.3252M → False solution. Produce negative concentrations
Replacing, equilibrium concentrations will be:
[I₃⁻] = 0.0049M
[I₂] = 0.0352M
That would be an ionic bond since it has electrons to spare, rather than a convalent bond where all the electrons are taken up thus it is not a good conductor
First, find the average of the measured value. You should get 286.
291 + 287 + 295 + 281 = 1154
1154/4 = 288.5
Subtract the accepted value (300) from the average measured value (286). Take the absolute value of your answer. You should get 14.
288.5 - 300 = -11.5 = 11.5
Divide the difference from the above problem (14) by the accepted value (300). You should get 0.0467.
11.5/300 = 0.0383
Multiply by 100%.
0.0383 × 100% = 3.83%
The percent error is 3.83%.