•To study some of the physical properties of two types of solids – ionic and molecular solids. •To classify three unknown substances as ionic compounds, polar covalent compounds or non-polar covalent compounds. •To identify the three unknowns.
Melting Point100 – 525 ℃> 525 ℃< 100 ℃
Odour SubtleNoneVery Strong
1.Identify the type of solid in each unkown compound. Support these conclusions with observations. Compound A is a polar covalent compound because it has many “ in between” properties, such as the following: •The compound is soluble in water, which is usually an ionic property. •The compound melted at a temperature between 100 and 525 degrees Celsius, which is not a definite property of ionic or non-polar covalent bonds. Hence, it is covalent. •Having a subtle odour suggests that that the compound is not intermolecularly strong or weak. The intermolecular formation is moderate, which is a very polar covalent property.
Compound B is an ionic compound for the following reasons:
•It dissolved in water and almost all ionic compounds are very soluble in water. •It had a very high melting point, which is one of the definite properties of ionic compounds. •Electrical conductivity was high when dissolved in water, which is a property of all ionic compounds.
Compound C is a non-polar covalent compound for the following reasons •The compound is insoluble in water but soluble in alcohol. •The compound does not conduct electricity, which is a definite non-polar property. •The compound’s smell is very strong, which means that the intermolecular bond is very weak to let the smell pass through. Non-polar covalent compounds have weak intermolecular bonds. •The compound’s melting point is very low, which is another sign of weak intermolecular structure, a...