An impure sample of substance X melts at about 113 degress. Which of the substances could be X and state y

Resorcinal 111 degrees
Catechol 105
Nitrophenol 114
Butanamide 115

I think it is either catechol or resorcinol because as stated the higher the percentage of impurity the lower the melting point

I think you have the right idea but you aren't processing it correctly. It is true that the presence of an impurity makes the melting point decrease; therefore, the melting point of the impure sample must be less than the melting point of the pure sample. Doesn't that mean that the melting point of pure X must be higher than 113?

Based on the given information, the substance X, which has a melting point of about 113 degrees, could potentially be either resorcinol or nitrophenol. This is because, as you correctly mentioned, impurities tend to lower the melting point of a substance.

Catechol has a melting point of 105 degrees, which is lower than the observed melting point of substance X. Butanamide has a melting point of 115 degrees, which is higher than the observed melting point of substance X.

Therefore, based on the options provided, the most likely substance X is resorcinol, with a melting point of 111 degrees.

To determine which substance could be X, we need to compare the melting point of the impure sample (113 degrees) with the melting points of the given substances.

As you correctly noted, the higher the percentage of impurity, the lower the melting point of the substance. So, the impure sample of substance X is expected to have a lower melting point compared to the pure forms of the substances listed.

Let's compare the melting points:

Resorcinol: 111 degrees
Catechol: 105 degrees
Nitrophenol: 114 degrees
Butanamide: 115 degrees

Based on this information, the impure sample of substance X could potentially be either resorcinol or catechol. Both of these substances have melting points lower than 113 degrees, indicating that they can be affected by impurities.

However, without additional information or more precise melting point data, we cannot definitively determine the exact substance X.