Question

The ratio of number of alcohol group in compounds: Glycerol, Ethylene glycol and Tertiary butanol is respectively (A) \(1: 2: 3\) (B) \(3: 2: 1\) (C) \(2: 3: 1\) (D) \(3: 1: 2\)

Short answer

The ratio of alcohol groups in Glycerol, Ethylene glycol, and Tertiary butanol is \(3:2:1\). Therefore, the correct answer is (B).

Step-by-step solution

Write the structural formula for each compound

Glycerol - \(C_3H_8O_3\): CH2OH-CHOH-CH2OH Ethylene glycol - \(C_2H_6O_2\): HO-CH2-CH2-OH Tertiary butanol - \(C_4H_{10}O\): (CH3)3C-OH

Count the alcohol groups

In Glycerol, we have 3 alcohol groups: CH2OH, CHOH, CH2OH In Ethylene glycol, we have 2 alcohol groups: HO, OH In Tertiary butanol, we have 1 alcohol group: OH

Find the ratio

The ratio of alcohol groups in Glycerol, Ethylene glycol, and Tertiary butanol is: \(3:2:1\)

Choose the correct answer

According to our calculation, the correct ratio of the alcohol groups is \(3:2:1\), which corresponds to option (B). So, the correct answer is (B).

Key concepts

Glycerol

Glycerol is a simple polyol compound; it's also known as glycerin or glycerine. In its structure, glycerol is composed of three carbon atoms, which are each bonded to an alcohol (\( -OH \)) group. This structure is represented as \( CH_2OH-CHOH-CH_2OH \). Due to this tri-ol structure, glycerol is known as a trihydric alcohol.

Because it contains three alcohol groups, glycerol is highly hydrophilic, meaning it attracts water, making it useful in products that require moisture retention, such as cosmetics and pharmaceuticals.

• Structure: Three alcohol groups in glycerol allow it to form hydrogen bonds, increasing its boiling point and solubility in water.
• Applications: Glycerol is utilized in making soaps, as a food sweetener, and in the medical field for treatments.

Its multiple \( -OH \) groups give it a syrupy consistency and a mildly sweet taste.

Ethylene Glycol

Ethylene glycol is a diol, meaning it has two alcohol groups attached to its carbon atoms. The chemical formula for ethylene glycol is \( C_2H_6O_2 \), and its structural representation is \( HO-CH_2-CH_2-OH \). Thanks to its two \( -OH \) groups, ethylene glycol is particularly useful as an antifreeze.

• Key Uses: This compound is widely used in automotive antifreeze and as a precursor to polymers.
• Structure: The presence of two alcohol groups allows it to form hydrogen bonds, which contribute to its high boiling point and low freezing point.

Furthermore, ethylene glycol's alcohol groups boost its solubility in water, making it an excellent solvent. However, it's important to handle this compound with care because it is toxic when ingested.

Tertiary Butanol

Tertiary butanol, also known as tert-butanol or t-butanol, is a type of alcohol where the central carbon atom is bonded to three other carbon atoms and one \( -OH \) group. This tertiary alcohol has the chemical formula \( C_4H_{10}O \), and its structure can be represented as \( (CH_3)_3C-OH \).

Tertiary butanol is known for its relative stability as an alcohol, owing to the branching of its carbon structure.

• Stability: With one alcohol group, it forms fewer hydrogen bonds compared to other alcohols like glycerol and ethylene glycol.
• Uses: Tertiary butanol serves as a solvent in organic chemistry and is used in the production of cosmetics and flavors.

Its unique structure not only contributes to its high melting and boiling points but also results in its being a white crystalline solid at room temperature.