Question

Choose the correct option for which is not the structure of ${\mathrm{C}}_4{\mathrm{H}}_9\mathrm{Br}$.

• A. Bromobutane
• B. $2-$Bromobutane
• C. $1-$Bromo$-2-$methylpropane
• D. Isobutane

Answer 1

The correct option is D

Isobutane

The explanation for the correct option:

Option (D): Isobutane

• Bromobutane, or ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Br}$ is an organobromine chemical. it is a colorless liquid but yellowish when impure.
• It is water-insoluble, but it is soluble in organic solvents.
• There are four structural isomers present in Bromobutane namely $1-$Bromobutane, $2-$Bromobutane, $1-$Bromo$-2-$methylpropane, and $2-$Bromo$-2-$methyl propane.
• 
• Structural isomerism refers to isomerism in which isomers have various atom configurations inside the same molecule.
• sec-butyl bromide or methyl-ethyl bromomethane are two names for $2-$Bromobutane. It is combustible and poisonous, but it is relatively stable.
• $1-$Bromo$-2-$methylpropane is an isomer of bromobutane in which the bromine group is attached to the first carbon and the methyl group is attached to the second carbon.
• It's used to make $1-$ethyl$-1,3-$isobutylimidazolium bromide.
• 2-Bromo-2methyl propane or also known as tert-butyl because a tert-butyl group is connected to a bromide substituent in the molecule.
• In synthetic organic chemistry, this organobromine molecule is used as a reagent.
• Isobutane is an isomer of butane with the chemical formula $\mathrm{HC}{\left({\mathrm{CH}}_3\right)}_3$
• It is a gas that is colorless and odorless. With a tertiary carbon atom, it is the most basic alkane.
• Therefore, isobutane is not an isomer of Bromobutane
• Hence, it is the correct option.

The explanation for the correct options:

Option (A): Bromobutane

1. Bromobutane, or ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Br}$ is an organobromine chemical. it is a colorless liquid but yellowish when impure.
2. Structural isomerism refers to isomerism in which isomers have various atom configurations inside the same molecule.
3. There are four structural isomers present in Bromobutane namely $1-$Bromobutane, $2-$Bromobutane, $1-$Bromo$-2-$methylpropane, and $2-$Bromo$-2-$methyl propane.
4. In Bromo butane, the Bromine atom is attached to the first carbon.
5. 
6. Hence, it is the correct option.

Option (B): $2-$Bromobutane

1. Bromobutane, or ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Br}$ is an organobromine chemical. it is a colorless liquid but yellowish when impure.
2. There are four structural isomers present in Bromobutane namely $1-$Bromobutane, $2-$Bromobutane, $1-$Bromo$-2-$methylpropane, and $2-$Bromo$-2-$methyl propane.
3. In $2-$Bromobutane, the bromine atom is attached to the second carbon.
4. 
5. Hence, it is the correct option.

Option (C): $1-$Bromo$-2-$methylpropane

1. Bromobutane, or ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{Br}$ is an organobromine chemical. it is a colorless liquid but yellowish when impure.
2. There are four structural isomers present in Bromobutane namely $1-$Bromobutane, $2-$Bromobutane, $1-$Bromo$-2-$methylpropane, and $2-$Bromo$-2-$methyl propane.
3. When combined with $1-$ethylimidazole, $1-$Bromo-$2-$methylpropane is employed as a synthetic reagent to create $1-$ethyl$-1,3-$isobutylimidazolium bromide.
4. Hence, it is the correct option
5. 

Therefore, Isobutane is not the structure of ${\mathrm{C}}_4{\mathrm{H}}_9\mathrm{Br}$