posted by INEEDHELP!!! on .
list three differences between molecular and ionic compounds, and explain how they relate to the differences in bond types.....how do i relate to the differences in bond types?
List the differences and we'll talk about how they relate to the bond type.
1. molecular compounds are molecules, and ionic compounds are ions.
2. ionic compounds loose and gain electrons, molocular ompounds don't
3. molecules compounds are made up of electrons, ionic compounds are made up of elements
1 is ok.
2. ionic compounds DO lose an gain electrons and molecular compounds don't; however, you should say that molecular compounds share electrons.
3. Your number 3 is not correct and what it says doesn't make sense. For a #3 you could say that molecular compounds consist of single molecules, in most cases, while ionic compounds consist of a three dimensional array of ions. For example, the formula for salt is NaCl and it is true that there is 1 Na for each 1 Cl; however, these alternating ions of Na and Cl spread out in all three directions so that the "real" formula is NaxClx and x is a very large number.
4. Most molecular compounds are not soluble in polar solvents (such as water); most ionic compounds are. Most ionic compounds are not soluble in non-polar solvents but molecular compounds are.
5. Molten ionic compounds and their aqueous solutions conduct electricity; molecular compounds dissolved in non-polar solvents do not.
6. Molecular compounds tend to have low melting points and boiling points; ionic compounds have high melting points and boiling points.
7. Molecular compounds usually are softer than ionic compounds (diamond is an exception); ionic compounds are hard and brittle.
Knowing that ionic compounds are formed by elements losing and gaining electrons and molecular compounds are formed by sharing electrons (your #2) and that molecular compounds are single molecules and ionic compounds are ions in a three dimensional array (your #1 and my #3 addition), can you come up with reasons for these differences?
One example here. Solubility of ionic compounds in polar solvents. Ionic compounds are VERY polar (since they consist of ions). These ions are attracted to the dipoles of the polar water molecule and these attractions are responsible for breaking the ionic bonds of ionic crystals. That is, the crystal lattice is broken and the ions go into solution in the polar solvent. On the other hand, molecular compounds have bonds in which the electrons are shared, they are not polar, and they will not dissolve in a polar solvent. They WILL, however, dissolve in non-polar solvents (remember like dissolves like) while ionic compounds will not dissolve in non-polar solvents.
why do molecular compounds not dissolve in water??