The boiling points for a set of compounds in a homologous series can be qualitatively predicted using intermolecular force strengths. using their condensed structural formulas, rank the homologous series for a set of alkanes by their boiling point.

rank from highest to lowest boiling point. to rank items as equivalent, overlap them.

a)ch3ch2ch2ch3
b) ch3ch2ch2ch2ch2ch3ch3
c) ch3ch2cch2ch3ch3
d)ch3ch2ch2ch2ch2ch2ch3

Descending order of boiling point: (d)  > (c) > (b) > (a)

Explanation:

The given compounds are:

a) CH₃CH₂CH₂CH₃ – butane (4 carbon Straight-change)

b) CH₃CH₂CH₂CH₂CH₂CH₃ – hexane (6 carbon Straight-change)

c) CH₃CH₂C(CH₃)₂CH₂CH₃ – 3,3-dimethylpentane (7 carbon Branched chain)

d)CH₃CH₂CH₂CH₂CH₂CH₂CH₃ – heptane (7 carbon Straight-change)

Boiling point is defined as the temperature at which the substance changes from the liquid to the vapor state. It is generally dependent upon the molecular mass, branching and the intermolecular forces.

Since all the given compounds are alkanes. Thus, they all exhibit weak intermolecular van der Waals forces.

Therefore, the boiling point of alkanes depends only on the molecular mass or the number of carbon atoms and the branching.

The boiling point of a molecule increases with molecular mass or the number of carbons and decreases with branching.

Therefore, the descending order of boiling point of alkanes is:

(d) CH₃CH₂CH₂CH₂CH₂CH₂CH₃ (heptane, 7 carbon Straight-change) >

(c) CH₃CH₂C(CH₃)₂CH₂CH₃(3,3-dimethylpentane, 7 carbon Branched-chain) >

(b) CH₃CH₂CH₂CH₂CH₂CH₃ (hexane, 6 carbon Straight-change) >

(a) CH₃CH₂CH₂CH₃ (butane, 4 carbon Straight-change)

here we have to get the change of moles on decrease the volume of the reaction in gas phase.

the   per the given options it will decrease by (d) 11-50%

we know, on decreasing the volume of the gas phase reaction the reaction moves to the product side.

the reaction:                     so₂cl₂ (g) = so₂ (g) + cl₂ (g)         total

the moles at equilibrium:   1 - α                 α               α           = 1+α

concentrations:                   1 - α               α               α           = 1 + α

(concentration = moles/volume, as volume is 1 l)

(where α is the degree of dissociation)

now the dissociation constant in terms of concentration is :

=  

or,

or,   = (at v = 1l)

the reaction:                     so₂cl₂ (g) = so₂ (g) + cl₂ (g)         total

the moles at equilibrium:   1 - α                 α               α           = 1+α

concentrations:               (1 - α)/0.5           α/0.5         α/0.5       = (1 + α)/0.5

thus, the dissociation constant in terms of concentration is :

or,  

=  

so, the change of 1 : 1/0.5

or, 1: 2

thus it will decrease by 50%.

or, as per the given options it will decrease by 11-50%

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.