Which molecule or compound below contains a polar covalent bond?
Student Response
A. NCl3
B. C2H4
C. ZnS
D. AgCl
E. LiI
Well, molecules have a way of getting quite "bonded" to each other, but let's see which one has a polar covalent bond. Hmmm... Ah, got it! The molecule with a polar covalent bond is D. AgCl. I mean, who wouldn't want a bond between silver and chlorine? They're like the Batman and Robin of the periodic table!
The compound that contains a polar covalent bond is D. AgCl (silver chloride).
To determine which molecule or compound contains a polar covalent bond, we need to understand the concept of electronegativity. Electronegativity refers to an atom's ability to attract electrons towards itself in a chemical bond.
In a polar covalent bond, the electrons are not shared equally between the atoms involved. Instead, one atom has a stronger pull on the electrons, causing a partial negative charge on that atom and a partial positive charge on the other atom.
To determine if a molecule or compound has a polar covalent bond, we compare the electronegativities of the atoms involved. The greater the difference in electronegativity, the more polar the bond.
Let's examine each option:
A. NCl3: Nitrogen (N) has an electronegativity of 3.04, and chlorine (Cl) has an electronegativity of 3.16. The electronegativity difference is small, suggesting a mostly covalent bond, but it is polar due to the small difference.
B. C2H4: Carbon (C) and hydrogen (H) have electronegativities of 2.55 and 2.20, respectively. Since the electronegativity difference is relatively small, the bond is nonpolar covalent.
C. ZnS: Zinc (Zn) has an electronegativity of 1.65, and sulfur (S) has an electronegativity of 2.58. The electronegativity difference is significant, suggesting an ionic bond, not a polar covalent bond.
D. AgCl: Silver (Ag) has an electronegativity of 1.93, and chlorine (Cl) has an electronegativity of 3.16. The electronegativity difference is significant, suggesting an ionic bond, not a polar covalent bond.
E. LiI: Lithium (Li) has an electronegativity of 0.98, and iodine (I) has an electronegativity of 2.66. The electronegativity difference is significant, suggesting an ionic bond, not a polar covalent bond.
Based on the electronegativity differences, the correct answer is A. NCl3, as it contains a polar covalent bond.
C,D,E are ionic
B is covalent
that leaves A
What you need to do is grab a periodic table with electronegativies, calculate the differences, and use that to determine bond type.