The smaller coil size of a branched chain will tend to decrease the viscosity, although branches long enough to entangle produce a broadened terminal zone and larger viscosity.

Branching decreases the boiling point As the length of carbon chain increases, the surface area of the compound will also increase. Van der Waals dispersion force is proportional to the surface area. Branching in molecules decreases the surface area thereby decreasing the attractive force between individual molecules.

As branching increases, the surface area of the molecule decreases which results in a small area of contact. As a result, the Van der Waals force also decreases which can be overcome at a relatively lower temperature. Hence, the boiling point of an alkane chain decreases with an increase in branching.

The general explanation given is that the chains are further apart, so the intermolecular forces are less, and as they are further apart, they occupy more volume, and the density is lesser.

Increasing the degree of crystallinity increases hardness and density. This makes it stiff and dense, and it is used for milk bottles and drainpipes. The numerous short branches in LDPE (low density poly(ethene)) interfere with the close packing of molecules, so they cannot form an ordered structure.

Branching also affects chain entanglement, the ability of chains to slide past one another, in turn affecting the bulk physical properties. Long chain branches may increase polymer strength, toughness, and the glass transition temperature (Tg) due to an increase in the number of entanglements per chain.

The linear polysaccharides with highly regular conformation that can form crystalline or partial crystalline structures are mostly insoluble in water, while branching structure could increase the solubility for two reasons: (1) the branching structure could weaken the intramolecular interaction due to the steric …

Branched alkane hydrocarbons are thermodynamically more stable than straight-chain linear alkanes. Because the steric and quantum energy terms cancel, this leaves the electrostatic energy term that favors alkane branching.

Since the same bonds are formed and broken in every hydrogenation reaction, the heat of hydrogenation is measuring the stability of each type of alkene. This means that the lower the heat of hydrogenation, the greater the stability of the alkene.

Branched alkanes normally exhibit lower boiling points than unbranched alkanes of the same carbon content. This occurs because of the greater van der Waals forces that exist between molecules of the unbranched alkanes. The strong repulsive forces counterbalance the weak van der Waals forces of attraction.

2 Answers. Any differences in the heat given off can be used to say that a compound is more stable (it had a lower energy to begin with, so less heat is given off) or less stable (it had a higher energy to begin with, so more heat is given off). This link provides the heats of combustion for some useful model compounds …