Identifying 3 Unkown Compounds (Physical Properties of Ionic and Molecular Solids) Essay Example
Purpose:
• 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.
Observations: A B C
Solubility in:
• H2O
• 2-Propanol
Soluble
Insoluble
Soluble
Insoluble
Insoluble
Soluble
Conductivity None High None
Melting Point 100 – 525 ℃ > 525 ℃ < 100 ℃
Odour Subtle None Very Strong
Concluding Questions:
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
• 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.
Observations: A B C
Solubility in:
• H2O
• 2-Propanol
Soluble
Insoluble
Soluble
Insoluble
Insoluble
Soluble
Conductivity None High None
Melting Point 100 – 525 ℃ > 525 ℃ < 100 ℃
Odour Subtle None Very Strong
Concluding Questions:
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