I believe the answer you are looking for is the 4th one.
The correct answer is hydrogen<span>, and </span>oxygen<span>. </span>
Answer:
a)CH₄, BH₃, and CCl₄
Explanation:
<u>London dispersion forces:-
</u>
The bond for example, in the molecule is F-F, which is non-polar in nature because the two fluorine atoms have same electronegativity values.
The intermolecular force acting in the molecule are induced dipole-dipole forces or London Dispersion forces / van der Waals forces which are the weakest intermolecular force.
Out of the given options, H₂O , NH₃ exhibits hydrogen bonding which is:-
<u>Hydrogen bonding:-
</u>
Hydrogen bonding is a special type of the dipole-dipole interaction and it occurs between hydrogen atom that is bonded to highly electronegative atom which is either fluorine, oxygen or nitrogen atom.
Thus option B and C rules out.
<u>Hence, the correct option which represents the molecules which would exhibit only London forces is:- a)CH₄, BH₃, and CCl₄</u>
<h2>Heptene formed is -</h2><h2>

</h2>
Explanation:
The two possibilities when the peroxide is not present
+ HBr →
In presence peroxide,
≡
+ HBr →
- When peroxides are present in the reaction mixture, hydrogen bromide adds to the triple bond of heptane with regioselectivity.
- This reaction is opposite to that of Markovnikov's rule which says that when asymmetrical alkene reacts with a protic acid HX, then the hydrogen of an acid is attached to the carbon with more in number of hydrogen substituents, and the halide (X) group is attached to the carbon with more in number of substituents of alkyl.
- One mole of HBr adds to one mole of 1-heptane.
- The structure of heptene formed is -

Answer: Option (a) is the correct answer.
Explanation:
A miscible solution is defined as the one in which two or more than two components are soluble with each other.
So, when hexane is added to heptane then both of them will mix with each other and hence they are miscible. This mixing will lead to formation of more number of ions into the solution as a result, more will be the disorder present in the solution.
As entropy is the degree of randomness present.
Hence, we can conclude that a solution of hexane and heptane will lead to an increase in entropy.