Which of the following bases is the WEAKEST? The base is followed by its Kb value. Which of the following bases is the WEAKEST? The base is followed by its Kb value. (CH3CH2)3N, 5.2 × 10-4 C5H5N, 1.7 × 10-9 NH3, 1.76 × 10-5 HOCH2CH2NH2, 3.2 × 10-5 Since these are all weak bases, they have the same strength.

C₅H₅N is weakest base due to it's lowest Kb values.

Explanation:

Basic strength of an organic base is directly proportional with Kb(base dissociation constant) value.

Since Pyridine (C₅H₅N) is weakest base due to its lowest Kb value.

The reason of low basicity are as follows

1) lone pair containing orbital of nitrogen is sp² hybridised which is more electronegative as compare to sp³ orbital.

2) The conjuagte acid of pyridine is least stable as compare to other conjugate acids of corresponding bases.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance