Which chloride should exhibit the most covalent type of bond? WHY?
A) NaCl B) KCl C) BaCl2 D) BeCl2
E) CaCl2
It's BeCl2. It has the least difference in electronegativities between the two elements.
I would think BeCl2. Small compact cation, not very electropositive.
The chloride that should exhibit the most covalent type of bond is BeCl2, option D.
The covalent bond is formed when two atoms share electrons. In general, the larger the difference in electronegativity between two atoms, the more ionic the bond becomes. Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond.
Beryllium (Be) is a metal with a low electronegativity, while chlorine (Cl) is a nonmetal with a high electronegativity. Since Be and Cl have relatively small differences in electronegativity, the bond formed between them in BeCl2 is more covalent in nature.
On the other hand, sodium (Na), potassium (K), barium (Ba), and calcium (Ca) are all metals with higher electronegativities as compared to beryllium. Therefore, the bonds formed between these metals and chlorine (in NaCl, KCl, BaCl2, and CaCl2) are more ionic in nature.
Hence, the correct answer is option D) BeCl2.
To determine which chloride should exhibit the most covalent type of bond, we need to consider the electronegativity difference between the atoms.
Electronegativity is a measure of the tendency of an atom to attract a shared pair of electrons towards itself in a chemical bond. When there is a higher electronegativity difference between atoms, the bond tends to be more ionic. Conversely, when there is a lower electronegativity difference, the bond tends to be more covalent.
In this case, we need to compare the electronegativity of the cations (metal atoms) in the chlorides. The cations in the options are Na+, K+, Ba2+, and Ca2+.
Now let's look at the options:
A) NaCl: Sodium (Na) has an electronegativity of 0.93.
B) KCl: Potassium (K) has an electronegativity of 0.82.
C) BaCl2: Barium (Ba) has an electronegativity of 0.89.
D) BeCl2: Beryllium (Be) has an electronegativity of 1.57.
E) CaCl2: Calcium (Ca) has an electronegativity of 1.00.
From the given options, we observe that Beryllium (Be) in BeCl2 has the highest electronegativity difference compared to Chlorine (Cl). Therefore, BeCl2 should exhibit the most covalent type of bond.
In summary, the correct answer is D) BeCl2 because beryllium has the highest electronegativity difference with chlorine, suggesting a higher tendency for a covalent bond.