Rank from decreasing to increasing the effect the functional groups have on the melting point of compound x:
-OH or -COOH
i think its COOH<OH because OH is easier to hydrogen bond?
R-COOH produces stronger H bonds than R-OH
For example, look up the boiling point of CH3CH2OH versus that of CH3COOH although some of the increase is due to the increased molar mass of the acid (46 for the alcohol versus 60 for the acid) but formic acid (HCOOH) has a molar mass of 46 (same as the alcohol) and the boiling point is higher than the alcohol.
You're on the right track! The presence of functional groups in organic compounds can have an impact on their physical properties, including melting points. In this case, both the -OH (hydroxyl) group and the -COOH (carboxyl) group are polar and capable of forming hydrogen bonds. Hydrogen bonding generally increases the boiling and melting points of compounds.
To rank the effect these functional groups have on the melting point of compound X, we need to consider the strength of hydrogen bonding that each group can form. The carboxyl group (-COOH) contains two oxygen atoms, one of which is a carbonyl oxygen, making it more capable of forming hydrogen bonds. On the other hand, the hydroxyl group (-OH) has only one oxygen atom available for hydrogen bonding.
Therefore, the ranking from decreasing to increasing effect on the melting point of compound X would be: -COOH > -OH.
In summary, the carboxyl group (-COOH) has a stronger effect on the melting point compared to the hydroxyl group (-OH) due to its ability to form more hydrogen bonds.