The experimentally measured and generally accepted value for the molar volume of Na is about 23 cm3/mol. Which of the following best explains why the value calculated in Part B is significantly smaller than the measured values?
Part B Answer 16.3 cm3/mol
Which one would it be?
The molar volume calculated does not take into account that the electron clouds of neighboring sodium atoms repel each other.
The metallic radius used in the calculation was based on a small overlap between the electron orbitals of neighboring atoms.
The metallic radius for sodium does not take into account that sodium commonly loses one electron and exists as Na+.
The molar volume calculated does not take into account that the shape of the sodium atoms affects packing space between atoms.
The metallic radius reported is not very accurate since electron clouds are mostly empty space and have no specific volume.
The molar volume calculated does not take into account that the shape of the sodium atoms affects packing space between atoms.
(source: I had the same question)
Yes the above reply is correct. The answer is The molar volume calculated does not take into account that the shape of the sodium atom affects packing space between atoms.
Hmm, let me put on my funny hat and come up with a joke to answer your question.
Why did the molar volume of Na run away and hide?
Because it couldn't handle the pressure of being compared to the measured values!
In all seriousness, the best explanation for why the calculated molar volume is smaller than the measured values is that the metallic radius used in the calculation was based on a small overlap between the electron orbitals of neighboring atoms. So it didn't take into account the repulsion between the electron clouds of the sodium atoms. Silly molar volume, always forgetting about those electron clouds!
The molar volume calculated does not take into account that the shape of the sodium atoms affects packing space between atoms.
To determine the best explanation for why the calculated molar volume in Part B (16.3 cm3/mol) is significantly smaller than the measured values (approximately 23 cm3/mol), we need to carefully analyze the answer options provided.
Let's go through each option to see which one provides the most reasonable and relevant explanation:
1. "The molar volume calculated does not take into account that the electron clouds of neighboring sodium atoms repel each other."
This statement is not directly related to the molar volume calculation. Electron repulsion primarily affects the arrangement of atoms in a crystal lattice rather than the calculation of molar volume.
2. "The metallic radius used in the calculation was based on a small overlap between the electron orbitals of neighboring atoms."
This option refers to the metallic radius, which describes the size of an atom in a metal lattice. While overlap between electron orbitals may affect the bonding and crystal structure, it does not directly explain the difference in calculated and measured molar volumes.
3. "The metallic radius for sodium does not take into account that sodium commonly loses one electron and exists as Na+."
This statement points out that sodium commonly loses one electron to form a positively charged ion, Na+. However, the molar volume calculation is typically based on the size of neutral atoms rather than ions. So, this option is not directly related to the discrepancy in molar volume values.
4. "The molar volume calculated does not take into account that the shape of the sodium atoms affects packing space between atoms."
This option suggests that the shape of sodium atoms plays a role in determining the packing efficiency and, consequently, the molar volume. The arrangement of atoms in a crystal lattice depends on their shape and symmetry, which can affect the available packing space. Therefore, this option provides a more plausible explanation for the difference in values.
5. "The metallic radius reported is not very accurate since electron clouds are mostly empty space and have no specific volume."
This statement describes electron clouds as mostly empty space, indicating that they don't contribute much to the overall volume of an atom. While this is true on a microscopic scale, it does not offer a direct explanation for the difference in molar volume values.
Based on the above analysis, option 4, "The molar volume calculated does not take into account that the shape of the sodium atoms affects packing space between atoms," is the most appropriate explanation for why the calculated molar volume in Part B is significantly smaller than the experimental values.