Question

which of the following will have the smallest value of vander waal's constant 'a'
a nh3 b co2 c ch4 d he
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Answer 1

Answer:

CHEMISTRY

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Asked on December 26, 2019 by

Dumpa Suryadevara

MEDIUM

Which of the substance has the smallest value of van der Waal's constant

′

a

′

?

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ANSWER

Option (B) is correct.

The value of the Van der Waals constant,

′

a

′

, of a given gaseous substance depends on the strength of attractions between its component molecules. Molecules experiencing the weakest attractive forces will have the smallest a constant while those with the strongest attractive forces will have the largest a values.

Of the molecules NH

3

,N

2

,Cl

2

,CCl

4

, the two elements nitrogen and chlorine alone have non-polar bonds between their component atoms. This results is weaker attractions between molecules, so N

2

and Cl

2

will have the smallest

′

a

′

values. The remaining molecules all have polar bonds between their component atoms and in the case of NH

3

, hydrogen bonds between molecules. These are factors that lead to increased

′

a

′

constants. As the N

2

molecule is smaller than the Cl

2

molecule and therefore has less electrons present, the attractive forces between N

2

molecules will be weaker than those between Cl

2

molecules and N

2

will have the smallest

′

a

′

constant.