Which of the following bases is the STRONGEST? The base is followed by its Kb. A. C6H5NH2, 4.0 × 10-10 B. NH3, 1.76 × 10-5 C. CH3NH2, 4.4 × 10-4 D. (CH3CH2)2NH, 8.6 × 10-4 E. C5H5N, 1.7 × 10-9

(D) (CH3CH2)2NH

Explanation:

In order to decide which base is strongest we need to calculate its PKb

PKb = -log [Kb]

A large Kb value and small PKb value gives the strongest base

 Compound                   Kb                           PKb      

(A) C6H5NH2 -         4 x 10^-10                      9.349

(B) NH3                     1.76x 10^-5                    4.754

(C) CH3NH2              4.4x 10^-4                     3.357

(D) (CH3CH2)2NH   8.6x 10^-4                     3.066

(E) C5H5N                  1.7x10^-9                      8.77  

Clearly (CH3CH2)2NH is the strongest base.

the correct answer is option d

explanation:

i was wrong its d because they dont use cm when calculating square roots

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.