Two colleagues are measuring the melting point of a substance. They observe two ranges of melting point, at 134-137 °C and 132-136 °C. What are the possible reasons that lead to two different values with exactly the same sample?

Explanation:

impurities affect both melting point and boiling point

in the case of melting point it lowers the melting point

so I guess one of the samples Ie contained impurities

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.