What carboxylic acid would be formed if the malonic ester synthesis (alkylation of diethyl malonate followed by hydrolysis with acidic workup and decarboxylation) were carried out with one equivalent of malonic ester, one equivalent of 1,5-dibromopentane, and two equivalents of hydroxide as the base

cyclohexilic acid

Explanation:

The malonic ester synthesis is often used to form different types of carboxilic acid. In this case, we have excess of base, so we can expect a ring formed in the molecule.

In the first step, the base substract the more acidic hydrogen of the ester. In the next step we have the ester reacting with the dibromopentane. Then, in the next step, the excess of base will substract again the acidic hydrogen remaining of the carbon, and then, will promove a Sn2 reaction with the bromine in the pentane (That it was previously attached to the molecule). In this step, a ring id formed. Then, the hydrolisis with acid, will form carboxilic acid in both sides of the molecule, and finally the decarboxilation in heat will separate the molecule and formed the cyclohexilic acid.

The picture below shows the mechanism

it is a solid

explanation:

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.