Answer :
To solve this problem, we need to calculate the average equilibrium constant [tex]K_c[/tex] based on the given data. An equilibrium constant [tex]K_c[/tex] is a number that describes the ratio of concentrations of products to reactants at equilibrium for a reversible chemical reaction, according to the formula:
[tex]K_c = \frac{[\text{FeSCN}^{2+}]}{[\text{Fe}^{3+}][\text{SCN}^{-}]}[/tex]
Let's review the information provided:
- For each test tube, you have the equilibrium concentrations of [FeSCN[tex]^{2+}[/tex]] and the initial concentrations of [Fe[tex]^{3+}[/tex]] and [SCN[tex]^{-}[/tex]].
- You're given the equilibrium constant [tex]K_c[/tex] for most of the data points, but you might notice a mix-up in one of them (0.000291); this seems incorrect and does not match typical [tex]K_c[/tex] values.
Now, ignoring the erroneous fourth [tex]K_c[/tex] value, let's calculate the average [tex]K_c[/tex] from the given data:
Calculate Average [tex]K_c[/tex]:
- Provided acceptable [tex]K_c[/tex] values are 323, 264, 278, and 0 (the last data point might seem incorrect as well).
- When averaging data, typically we discard values that seem incorrect or out of range. Here, since two values seem strongly incorrect (0 and 0.000291), let's only use 323, 264, and 278.
Calculate the Average:
[tex]\text{Average } K_c = \frac{323 + 264 + 278}{3} \approx 288.33[/tex]
So, the average equilibrium constant [tex]K_c[/tex], considering only the reliable data, is approximately 288.33.
When conducting experiments, it’s essential to verify the results, especially when discrepancies are present. Measurement errors or calculation mistakes can affect your data validity. Always check and confirm results to ensure accurate calculations in a laboratory setting.
