Molecular Polarity and Lone Pairs

The video tutorial covers the concept of molecular polarity, focusing on the analysis of various molecules such as carbon dioxide, carbon monoxide, nitrate ion, phosphorus pentachloride, benzene, xenon trioxide, sulfur dioxide, and boron trifluoride. It explains how to determine if a molecule is polar or nonpolar by examining bond polarity, lone pairs, and molecular symmetry. The tutorial emphasizes the importance of electronegativity differences and provides examples to illustrate these concepts.

What are the three main factors to consider when determining the polarity of a molecule?

• Atomic mass, bond length, and molecular weight

• Bond electronegativity, lone pairs, and molecular symmetry

• Number of atoms, atomic radius, and bond angle

• Molecular shape, bond order, and atomic number

Why is carbon dioxide considered a non-polar molecule despite having polar bonds?

• Because the molecule is symmetrical, causing polarities to cancel out

• Because carbon and oxygen have the same electronegativity

• Because it has a lone pair on the central atom

• Because it contains only single bonds

What makes the nitrate ion an interesting example in terms of polarity?

• It contains a metal and a non-metal

• It is symmetrical, making the overall molecule non-polar

• It has both polar and non-polar bonds

• It has a central atom with lone pairs

Why is phosphorus pentachloride considered non-polar?

• It has a high molecular weight

• It has a lone pair on the central atom

• It is symmetrical, with equal and opposite bond polarities

• It contains only non-polar bonds

What is the polarity of benzene and why?

• Polar, due to its lone pairs

• Non-polar, because it is composed of only carbon and hydrogen

• Non-polar, due to its high electronegativity

• Polar, because of its double bonds

What feature of xenon trioxide makes it a polar molecule?

• Its symmetrical shape

• The presence of a lone pair on the central atom

• Its ionic bonds

• The equal sharing of electrons

How does the presence of a lone pair on sulfur dioxide affect its polarity?

• It has no effect on the molecule's polarity

• It makes the molecule polar

• It makes the molecule non-polar

• It causes the molecule to become ionic

What is the significance of lone pairs in determining molecular polarity?

• They always make a molecule non-polar

• They can make a molecule polar if present on the central atom

• They only affect the bond angles

• They have no effect on molecular polarity

Which molecular geometries are exceptions to the rule that lone pairs make a molecule polar?

• Trigonal pyramidal and bent

• Octahedral and seesaw

• Tetrahedral and trigonal planar

• Square planar and linear

What is the final step in determining if a molecule is polar or non-polar?

• Analyzing the bond angles

• Counting the number of atoms

• Checking the molecular weight

• Assessing the symmetry of the molecule