Pre-Lab Worksheet

Which type of compound usually has higher melting points: ionic compounds or covalent compounds? What is the reason for this difference in melting points? (3 points)
- Ionic compounds usually has an higher melting points than covalent compounds. The reasoning for this difference in melting points is the electrostatic attraction between positive and negative bonds.

Do ionic compounds conduct electricity as: (3 points)
Solids?
Liquids?
Aqueous solutions (when the ionic compounds are dissolved in water)?
- Ionic compounds conduct electricity as liquids and aqueous solutions but do not conduct electricity as solids.

Do covalent compounds conduct electricity as: (3 points)
Solids?
Liquids?
Aqueous solutions (when the covalent compounds are dissolved in water)?
- Covalent compounds conduct electricity as solids but do not conduct electricity as liquids nor aqueous solutions.

Lab Worksheet

Part I:



Part II: Conclusion

1. Based on your observations in the lab, categorize each unidentified compound as ionic or covalent. Explain in one or two sentences why you categorized the compounds the way that you did.
- When I did Part II of the lab, I dragged both leads to the substances and neither of them lighted up so that’s how I ended up with ‘No’ as the results for all of the substances.

2. Explain, in your own words, the differences between ionic and covalent bonding that account for the differences in their melting points.
- In ionic bonding, electrons are lost by one atom (negative ion) and gained by another atom (positive ion) which attracts them together and explains it‘s strong attraction and high boiling and melting point. On the other hand, in covalent bonding, electrons are neither gained nor lose but are shared between two atoms which gives it a low boiling and melting point.

3. In order to conduct an electrical current, a substance must have charged particle s (ions or electrons) that are free-moving (able to move about throughout the sample).
a. Why do you think ionic compounds are not able to conduct electricity as solids, even though they can as liquids and in solution?
- Ionic compounds are not able to conduct electricity as solids because it’s atoms are not help together by its bond.

b. Based on your research and observations, why do you think pure (distilled) water does not conduct electricity but tap water usually does?
- Tap water contains electrolytes that pure (distilled) water does not have which is why tap water can conduct electricity and not pure (distilled) water.