Question

question 40 (1 point)
from the table given below, which base is the strongest?

row	base	$k_b$
b.	nh₃, ammonia	1.75 × 10⁻⁵
c.	c₂h₅nh₂, ethylamine	5.6 × 10⁻⁴
d.	c₅h₅n, pyridine	1.7 × 10⁻⁹
e.	c₆h₅nh₂, aniline	4 × 10⁻¹⁰

options: a, b, c, d, e

Explanation:

Step1: Recall the relationship between \( K_b \) and base strength

A larger \( K_b \) value indicates a stronger base because \( K_b \) (base dissociation constant) measures the extent of base dissociation in water. A higher \( K_b \) means more hydroxide ions (\( OH^- \)) are produced, making the base stronger.

Step2: Compare the \( K_b \) values of all bases

• For A (Methylamine): \( K_b = 4.4 \times 10^{-4} \)
• For B (Ammonia): \( K_b = 1.75 \times 10^{-5} \)
• For C (Ethylamine): \( K_b = 5.6 \times 10^{-4} \)
• For D (Pyridine): \( K_b = 1.7 \times 10^{-9} \)
• For E (Aniline): \( K_b = 4 \times 10^{-10} \)

Now, compare the magnitudes of these \( K_b \) values. We can see that \( 5.6 \times 10^{-4} \) (Ethylamine) is larger than \( 4.4 \times 10^{-4} \) (Methylamine), and both are larger than the \( K_b \) values of Ammonia, Pyridine, and Aniline.

Answer:

C. \( \text{C}_2\text{H}_5\text{NH}_2 \), Ethylamine