Which of these compounds contain elements that do not follow the octet rule? Explain. (Note: All the numbers are superscripts)
A. NF3
B. OF2
C. H2S
D. NI3
My understanding of the octet rule..is that it is not satisified in molecules w/ an odd no. of electrons, and in molecules where an atom has less, or more, than a complete octet of valence electrons.
That's my understand, also. Which do you think do not fit the rule?
NI3
The octet rule states that atoms tend to gain, lose, or share electrons in order to achieve a stable electron configuration with eight valence electrons. Let's analyze each compound and determine if any of them violate the octet rule:
A. NF3: Nitrogen has 5 valence electrons, and each fluorine atom has 7 valence electrons. When the atoms combine, nitrogen shares three electrons with each fluorine atom, resulting in all atoms having eight electrons around them. The octet rule is satisfied in NF3.
B. OF2: Oxygen has 6 valence electrons, and each fluorine atom has 7 valence electrons. When the atoms combine, oxygen shares two electrons with each fluorine atom, resulting in the oxygen atom having a total of 10 valence electrons instead of 8. Therefore, OF2 does not follow the octet rule because oxygen has more than eight valence electrons.
C. H2S: Hydrogen has 1 valence electron, and sulfur has 6 valence electrons. When the atoms combine, each hydrogen atom shares one electron with sulfur, and sulfur shares two electrons with each hydrogen atom. In total, sulfur ends up with eight valence electrons, and each hydrogen atom has two. The octet rule is satisfied in H2S.
D. NI3: Nitrogen has 5 valence electrons, and iodine has 7 valence electrons. When the atoms combine, each nitrogen atom shares three electrons with iodine, resulting in nitrogen having a total of six valence electrons instead of eight. Therefore, NI3 does not follow the octet rule because nitrogen has less than eight valence electrons.
In summary, the compounds OF2 and NI3 do not follow the octet rule.
To determine which of the compounds contain elements that do not follow the octet rule, we need to examine the electron configurations of the atoms involved.
Let's analyze each compound:
A. NF3:
Nitrogen (N) has 5 valence electrons, and each fluorine (F) atom has 7 valence electrons. The total number of valence electrons in NF3 is calculated as 5 + (3 × 7) = 26. In this compound, nitrogen shares three of its valence electrons with each fluorine atom, resulting in a total of 8 electrons around nitrogen and a formal charge of -1 on each fluorine. Since nitrogen does not have an octet, NF3 does not follow the octet rule.
B. OF2:
Oxygen (O) has 6 valence electrons. The total number of valence electrons in OF2 is calculated as 6 + (2 × 7) = 20. In this compound, oxygen shares two of its valence electrons with fluorine, giving it a total of 8 electrons around oxygen. Therefore, OF2 follows the octet rule.
C. H2S:
Hydrogen (H) has 1 valence electron, and sulfur (S) has 6 valence electrons. The total number of valence electrons in H2S is calculated as (2 × 1) + 6 = 8. In this compound, each hydrogen shares one of its valence electrons with sulfur, resulting in a total of 8 electrons around sulfur. Therefore, H2S follows the octet rule.
D. NI3:
Nitrogen (N) has 5 valence electrons. The total number of valence electrons in NI3 is calculated as 5 + (3 × 7) = 26. In this compound, nitrogen shares three of its valence electrons with each iodine (I) atom. This results in a total of 8 electrons around nitrogen and a formal charge of -1 on each iodine. As in NF3, nitrogen does not have an octet in NI3, so it does not follow the octet rule.
Therefore, compounds A (NF3) and D (NI3) contain elements (nitrogen) that do not follow the octet rule.