Q. 6.105 - An Introduction to General, Organic, and Biological Chemistry

Question

Consider the following bonds: $\mathrm{Ca} \mathrm{and} \mathrm{O},\mathrm{C} \mathrm{and} \mathrm{O}, \mathrm{K} \mathrm{and} \mathrm{O}, \mathrm{O} \mathrm{and} \mathrm{O}, \mathrm{N} \mathrm{and} \mathrm{O}$.

(a) Which bonds are polar covalent ?

(b) Which bonds are non polar covalent ?

(c) Which bonds are ionic?

(d) Arrange the covalent bonds in order of decreasing polarity.

Step-by-Step Solution

Answer

(a) $\mathrm{C} \mathrm{and} \mathrm{O}, \mathrm{N}\hspace{0.17em}\mathrm{and} \mathrm{O}$bonds are polar covalent bonds.

(b) $\mathrm{O} \mathrm{and} \mathrm{O}$are non polar covalent bond.

(c) $\mathrm{Ca} \mathrm{and} \mathrm{O} , \mathrm{K} \mathrm{and} \mathrm{O}\hspace{0.17em}$are ionic bonds.

(d) $\mathrm{C}-\mathrm{O}>\mathrm{N} -\mathrm{O}>\mathrm{O}-\mathrm{O}$ is the order of polarity.

Part (a) Step 1: Given Information

We need to find that bond which is polar covalent in  $\mathrm{Ca} \mathrm{and} \mathrm{O},\mathrm{C} \mathrm{and} \mathrm{O}, \mathrm{K} \mathrm{and} \mathrm{O}, \mathrm{O} \mathrm{and} \mathrm{O}, \mathrm{N} \mathrm{and} \mathrm{O}.$

Part (a) Step 2: Explanation

The bonds between $\mathrm{N} \mathrm{and} \mathrm{O} , \mathrm{C} \mathrm{and} \mathrm{O}$ are polar covalent bonds due to their different electronegativities which led to the unequal electron sharing resulting polarization. 

Part (b) Step 1: Given Information

We need to find that bond which is non polar covalent in $\mathrm{Ca} \mathrm{and} \mathrm{O},\mathrm{C} \mathrm{and} \mathrm{O}, \mathrm{K} \mathrm{and} \mathrm{O}, \mathrm{O} \mathrm{and} \mathrm{O}, \mathrm{N} \mathrm{and} \mathrm{O}.$

Part (b) Step 2: Explanation

The  diatomic bond $\mathrm{O} \mathrm{and} \mathrm{O}$ is non-polar and covalent as the electronegativity differences is 0.  

Part (c) Step 1: Given Information

We need to find that bond which is ionic in $\mathrm{Ca} \mathrm{and} \mathrm{O},\mathrm{C} \mathrm{and} \mathrm{O}, \mathrm{K} \mathrm{and} \mathrm{O}, \mathrm{O} \mathrm{and} \mathrm{O}, \mathrm{N} \mathrm{and} \mathrm{O}.$

Part (c) Step 2: Explanation

We know that $\mathrm{Ca} \mathrm{and} \mathrm{O} , K \mathrm{and} \mathrm{O}$ are ionic bonds because the bond is formed between metal and non metal.

Part (d) Step 1: Given Information

We are to Arrange the covalent bonds in order of decreasing polarity in $\mathrm{Ca} \mathrm{and} \mathrm{O},\mathrm{C} \mathrm{and} \mathrm{O}, \mathrm{K} \mathrm{and} \mathrm{O}, \mathrm{O} \mathrm{and} \mathrm{O}, \mathrm{N} \mathrm{and} \mathrm{O}.$

Part (d) Step 2: Explanation

Greater the electronegativity difference between the constituent atoms, greater will be the polarity. The electronegativity order of the above nonmetals follows the order:. Therefore, the correct decreasing order will be $\mathrm{C}-\mathrm{O}>\mathrm{N} -\mathrm{O}>\mathrm{O}-\mathrm{O}$