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!
1. If a solution has a high conductivity, it indicates that there are a lot of __________________ in solution. [Answer: ions]
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.
DrBob222, thank you so much for the very detailed information!
Let's go through your answers:
1. If a solution has a high conductivity, it indicates that there are a lot of __ions__ in the solution. - Correct!
2. Pure acetic acid does not conduct electricity, nor does pure water, but a mixture of the two does conduct. This is explained by __covalent bonds__. - Correct!
3. Pure water does not conduct electricity (to any measurable extent), but tap water does. This is because __tap water contains many ions__. - Correct!
4. Table salt does not conduct electricity, but when it is melted (at about 800°C) it becomes a great conductor. This is because - This phenomenon is due to the fact that in the solid state, table salt (sodium chloride) is held together by __ionic bonds__. These bonds are very strong and the charged particles (ions) are not free to move, hence no electrical conductivity. However, when salt is melted, the ionic bonds break, and the ions move freely in the liquid, allowing for the flow of electric current.
5. If you observe that a KF(aq) solution conducts electricity very well, you would conclude that - A KF(aq) solution is a solution of potassium fluoride, which is a __strong electrolyte__. A strong electrolyte dissociates almost completely into ions when dissolved in water, resulting in a high concentration of ions in solution. Therefore, if the KF(aq) solution conducts electricity very well, it suggests that there are numerous ions present in the solution.
To summarize, the answers for the last two questions are:
4. melted salt (ionic electrolyte)
5. the solution contains a strong electrolyte