Question

The iodide (I2) content of a commercial mineral water was measured by two methods that produced wildly different results.6 Method A found 0.23 milligrams of I2 per liter (mg/L) and method B found 0.009 mg/L. When Mn21 was added to the water, the I2 content found by method A increased each time that more Mn21 was added, but results from method B were unchanged. Which of the Terms to Understand describes what is occurring in these measure- ments? Which result is more reliable?

Answer 1

Answer:

Results from method B is more reliable than method A.

Explanation:

The two method that are used for the analysis produced different results. The first method that is method A  gives higher value of the iodine content than the method B.

When $Mn^{2+}$ was added to water, method A showed an increased in the iodine content and it increases with the increase in the amount of $Mn^{2+}$ .

Where as in the method B, there is no change in the results. Therefore the measurements provided by the method A shows an inference of $Mn^{2+}$ ion.

The measurement of the iodine content is affected by the presence of the ion $Mn^{2+}$ in water.

Since in method B there is no change in measurement, it is independent of the presence $Mn^{2+}$ ion in water.

As higher iodine content is given by method A, so $Mn^{2+}$  ion must be present in original water that must be interfering the measurement. Hence, method B is more reliable.