Hydrocarbons

Name the reactant D and the non-organic product E.

D ....................................................

E ....................................................

Give the name of the type of aromatic electrophilic substitution reaction taking place.

Describe the conditions that are used to ensure substitution takes place only in the aromatic ring.

Draw the structures of the two major isomeric products of the reaction, formula $\text{C}_9\text{H}_{11}\text{Cl}$, when substitution takes place in the aromatic ring.

Describe the conditions that are used to ensure substitution takes place only in the side-chain.

Draw the structures of two isomeric products of the reaction, formula $\text{C}_9\text{H}_{11}\text{Cl}$, when substitution takes place in the side-chain.

Complete the following table to show the structures of the organic products formed when cumene reacts with each reagent.

Cumene can be nitrated using a mixture of concentrated nitric and sulfuric acids. The mechanism for this reaction is similar to the mechanism for the nitration of benzene.

Complete the mechanism for this reaction.

• Include all relevant charges and curly arrows showing the movement of electron pairs.
• Draw the structure of the intermediate.
• You do not need to draw the products.

Name the reactant D and the non-organic product E.

Give the name of the type of aromatic electrophilic substitution reaction taking place.

Describe the conditions that are used to ensure substitution takes place only in the aromatic ring.

Draw the structures of the two major isomeric products of the reaction, formula $\text{C}_9\text{H}_{11}\text{Cl}$, when substitution takes place in the aromatic ring.

Describe the conditions that are used to ensure substitution takes place only in the side-chain.

Draw the structures of two isomeric products of the reaction, formula $\text{C}_9\text{H}_{11}\text{Cl}$, when substitution takes place in the side-chain.

Complete the following table to show the structures of the organic products formed when cumene reacts with each reagent.

Cumene can be nitrated using a mixture of concentrated nitric and sulfuric acids. The mechanism for this reaction is similar to the mechanism for the nitration of benzene.

Complete the mechanism for this reaction.

• Include all relevant charges and curly arrows showing the movement of electron pairs.
• Draw the structure of the intermediate.
• You do not need to draw the products.

Suggest the structures of compounds T and U and draw them in the boxes above.

Suggest reagents and conditions for steps 1-5.

• step 1:
• step 2:
• step 3:
• step 4:
• step 5:

What types of reaction are steps 1 and 5?

• step 1:
• step 5:

Construct an equation for the formation of nitronium ions, $\text{NO}_2^+$, by this method.

Complete the scheme to show the mechanism for this reaction. Use curly arrows to show the movement of electron pairs.

Phenyl 2-hydroxybenzoate is an antiseptic.

Complete the following table about the reactions of phenyl 2-hydroxybenzoate with the three reagents.

There are several ways of introducing chlorine atoms into organic molecules. State the reagents and conditions necessary to carry out the following transformations.

When treated with concentrated $\text{HNO}_3 + \text{H}_2\text{SO}_4$ at 55 °C, benzene produces nitrobenzene.
Outline the mechanism of this reaction. You should include all charges, and use curly arrows to represent the movement of electron pairs.

In aromatic substitution of monosubstituted benzenes, the orientation of an incoming group depends on the nature of the group already attached to the ring.
For example, using the same reagents and conditions as in (i), methylbenzene and benzoic acid produce the following nitro compounds.

Using this information as an aid, suggest a structure for compound C in the following synthesis of 3-bromobenzoic acid.

Suggest reagents and conditions for steps 1 and 2.

step 1

step 2

Describe how you could carry out this reaction using chlorine.

Describe two observations you would make if this reaction was carried out with bromine.

Use bond energy data from the Data Booklet to calculate the $\Delta H^\ominus$ for this reaction when

$\text{X} = \text{Cl}$,

$\text{X} = \text{Br}$.

What is the major reason for the difference in these two $\Delta H^\ominus$ values?

What conditions are needed to carry out this reaction when X is bromine, Br?

Use bond energy data from the Data Booklet to calculate the $\Delta H^\ominus$ of this reaction for the situation where X is iodine, I.

Hence suggest why it is not possible to make iodomethane, $\text{CH}_3\text{I}$, by this reaction.

Explain the term homolytic fission.

Suggest the most likely organic radical that would be formed by the homolytic fission of bromochloromethane, $\text{CH}_2\text{BrCl}$. Explain your answer.

The reaction between propane and chlorine produces a mixture of many compounds, four of which are structural isomers with the molecular formula $\text{C}_3\text{H}_6\text{Cl}_2$.

Draw the structural or skeletal formulae of these isomers, and indicate any chiral atoms with an asterisk (*).

Suggest a reason why these reagents do not attack an alkane such as $\text{CH}_4$.

What is the name of this type of reaction?

Use equations to describe the mechanism of this reaction, naming the steps involved.

This reaction can produce organic by-products, in addition to $\text{C}_2\text{H}_5\text{Cl}$.
Draw the structural formulae of three possible organic by-products. Two of your by-products should contain 4 carbon atoms per molecule.
Briefly describe how each by-product could be formed.

It is found by experiment that, during this type of reaction, primary, secondary and tertiary hydrogen atoms are replaced by chlorine atoms at different rates, as shown in the following table.

Using this information, and considering the number of hydrogen atoms of each type (primary, secondary or tertiary) within the molecule, predict the relative ratio of the two possible products J and K from the chlorination of 2-methylpropane. Explain your answer.

ratio J / K = .....................................................

explanation:

In the boxes below draw the skeletal formulae of four different structural isomers of $\text{C}_5\text{H}_{11}\text{Cl}$ that could be obtained from the chlorination of 2-methylbutane. Indicate any chiral centres in your structures by an asterisk (*).

By means of an equation, illustrate the initial role of the sulfuric acid in this reaction.

Name the type of reaction and describe the mechanism for the nitration reaction, including curly arrows showing the movement of electrons and all charges.

type of reaction:

mechanism:

State the reagents and conditions needed to convert benzene into chlorobenzene.

Use these ideas to suggest the structures of the intermediate compounds Y and Z in the following synthesis of 4-chlorophenylamine.

Suggest the structural formulae of the products A, B, C and D of the following reactions. If no reaction occurs write "no reaction" in the relevant box.

Give the name or formula of the other product of this reaction.

In the presence of the catalyst, bromine can be considered to form the electrophile $\text{Br}^+$.

Complete the mechanism by which benzene reacts with $\text{Br}^+$, using curly arrows to show the movement of electron pairs.

Name this mechanism.

Identify a suitable reagent and a suitable catalyst for step 1.

Draw the structure of A.

Identify suitable reagents for steps 3 and 4.