Regarding conductivity:
1. If a solution has a high conductivity, it indicates that there are a lot of __________________ in solution. [Answer: ions]
2. Pure acetic acid does not conduct electricity, nor does pure water, but a mixture of the two does conduct. This is explained by __________________ [Answer: covalent bonds]
3. Pure water does not conduct electricity (to any measurable extent) but tap water does. This is because __________________ [Answer: tap water contains many ions]
4. Table salt does not conduct electricity, but when it is melted (at about 800°C) it becomes a great conductor. This is because __________________
5. If you observe that a KF(aq) solution conducts electricity very well, you would conclude that __________________
Please check my answers and what are the answers for the last two questions? Thanks!
2 answers
This is ok.
2. Pure acetic acid does not conduct electricity, nor does pure water, but a mixture of the two does conduct. This is explained by __________________ [Answer: covalent bonds]
I wouldn't answer that way although you are correct that both acetic acid and water have covalent bonds. The reason they don't conduct electricity in the pure state is because they are not composed of ions; however, when water is added to pure acetic acid the acetic acid ionizes. The equation is as follows:
CH3COOH + H2O ==> H3O^+ + CH3COO^- so you can see that ions are formed in the solution and that allows the solution to conduct electricity.
3. Pure water does not conduct electricity (to any measurable extent) but tap water does. This is because __________________ [Answer: tap water contains many ions]
I suppose in the grand scheme of things it does contain many ions but I think I would answer "some ions."
4. Table salt does not conduct electricity, but when it is melted (at about 800°C) it becomes a great conductor. This is because __________________
The solid table salt actually does consist of ions (Na ions and Cl ions); however, the crystal lattice keeps the ions from moving and there is no conduction. When the crystal is melted the ions are free to move about (from electrode to electrode) so the molten salt does conduct electricity.
5. If you observe that a KF(aq) solution conducts electricity very well, you would conclude that __________________
KF is a strong electrolyte or KF solution consists of many ions.