Arrange the following species in order of decreasing melting points: Ne, KF, C2H

Question

Arrange the following species in order of decreasing melting points: Ne, KF, C2H6, MgO, and H2S.

Be sure to justify your answers whenever you are asked a question like this. Note that compounds with strong intermolecular bonds hold to one another much more tightly. You can use the type of intermolecular bonding to arrange the melting points based on this, since melting involves breaking bonds. Do not simply list them in order of their melting points, which you could find by looking them up. Instead, explain which type of bonding each displays and why (which will be the bulk of your score on this question). Note also that MgO is an ionic compound, so that the “intermolecular” bonding is really between Mg2+ and O2- ions.

Explanation / Answer

MgO and KF are ionic solids which means that they have ionic interactions which are the strongest intermolecular interactions. Thus they will have the highest boiling points amongst all. Between these two, since Mg and O are bivalent ions, so their interactions are even stronger than between the monovalent K and F ions.

Next comes H2S because it is a polar molecule and has dipole interactions.

Next both C2H6 and Ne are having only Van der Waal's interactions, but those in ethane are stronger because of higher molecular mass of ethane.

Thus the correct order is:

MgO > KF > H2S > C2H6 < Ne

Hope this helps !

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.