What is Methyl Acetate Definition Formula Preparation Reactions and Uses
Methyl Acetate IUPAC Name
Methyl acetate is an ester known as MeOAc or methyl ester of acetic acid. The IUPAC name of methyl acetate is methyl ethanoate. This organic compound remains as a colorless liquid or vapor. However, the compound is toxic and only used as a solvent occasionally. It is weakly polar and does not readily dissolve in water. When heated its solubility in water increases, considerably. Methyl acetate is lipophilic and dissolves with fats. Methyl ethanoate is unstable in the presence of strong aqueous acids, or bases. The compound hydrolyzes in presence of strong acids and bases to give methanol and acetic acid. The conversion to its components is a first-order reaction of an ester concerning acid.
Methyl Acetate Structure
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Methyl Acetate Formula
Methyl acetate molecular weight: 74.08 g/mol
Methyl acetate chemical formula: C3H6O2
It appears as a clear colorless liquid with a pleasant fruity fragrance. It is volatile.
Methyl acetate boiling point: 56.80C
Methyl acetate melting point: -98.0oC
It is soluble in water. Solubility: 250C
It is also miscible with alcohol and ether, especially in ethyl ether and ethanol.
Methyl acetate density: 0.9342 g/cu cm at 200C
Methyl acetate vapor pressure: 216.2 mm Hg at 250C
Refractive index: 1.3614 at 200C
It decomposes upon heating or contact with air, bases, strong oxidizers, UV light and emits acrid smoke and toxic fumes when heated.
Methyl Acetate Uses
Methyl acetate is used as a flavoring agent in the form of a food additive. It is also used as a flavoring agent in various alcoholic beverages.
In the food industry, it is used in baking goods, gelatins, puddings, frozen dairy, and baked goods.
It is used as a solvent for many resins and oils such as nitrocellulose, acetyl cellulose, etc.
In industries, it is used as an adhesive, lubricants and lubricant additives, pigments, paint and coating additives, etc.
It is also used in electrical and electronic products, furnishing and cleaning products, floor coverings, ink, toner, and colorant products, etc.
It is used as a solvent for cleaning and degreasing purposes.
Production of Methyl Acetate
Methyl acetate can be prepared by the esterification reaction acetic acid with methanol at elevated temperature in presence of an esterification catalyst which can be strong acids like sulfuric acid.
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This reaction is done by the process of reactive distillation, where the separation of products of reaction does not need a separate distillation step.
The process includes constant feeding of methanol, acetic acid, and entrainer to the reaction kettle.
Here, reaction products are constantly removed from the reactive zone to increase the conversion. This production process was made popular by Eastman kodak.
For industrial purposes, methyl acetate is produced by the carbonylation of methanol as a byproduct of the acetic acid synthesis.
Hydrolysis of Methyl Acetate
Acid Hydrolysis of Methyl Acetate:
Methyl ethanoate or ethyl acetate, being an ester, hydrolysis to produce acetic acid and methyl alcohol when it is heated in the presence of an acid. The acid acts as a catalyst. The water molecule provides the -OH group to convert the carbonyl group present to a carboxyl group.
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Basic Hydrolysis of Methyl Acetate:
The basic hydrolysis of methyl acetate is also known as the saponification reaction of esters. In the reaction, when methyl acetate is heated in presence of a strong base such as NaOH it breaks down to give sodium salt of acetate ion and methyl alcohol.
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FAQs on Methyl Acetate Chemical Structure Properties and Applications
1. What is methyl acetate?
Methyl acetate is an organic ester with the chemical formula CH3COOCH3. It is formed from acetic acid (CH3COOH) and methanol (CH3OH) through an esterification reaction. Methyl acetate is a colorless, volatile liquid with a pleasant, fruity odor and is commonly used as a solvent in paints, coatings, and adhesives.
2. What is the chemical formula and molar mass of methyl acetate?
The chemical formula of methyl acetate is CH3COOCH3 and its molar mass is approximately 74.08 g·mol-1. The molar mass is calculated as:
- Carbon (C): 3 × 12.01 = 36.03 g·mol-1
- Hydrogen (H): 6 × 1.008 = 6.05 g·mol-1
- Oxygen (O): 2 × 16.00 = 32.00 g·mol-1
3. How is methyl acetate prepared in the laboratory?
Methyl acetate is prepared by the esterification reaction between acetic acid and methanol in the presence of a strong acid catalyst. The balanced reaction is:
CH3COOH(l) + CH3OH(l) ⇌ CH3COOCH3(l) + H2O(l)
- Concentrated H2SO4 is commonly used as a catalyst.
- The reaction is reversible and reaches equilibrium.
- Removal of water shifts the equilibrium toward ester formation.
4. What functional group is present in methyl acetate?
Methyl acetate contains the ester functional group (–COO–). In its structure, a carbonyl group (C=O) is bonded to an oxygen atom that is further attached to a methyl group. The structural formula can be written as CH3–COO–CH3, which is characteristic of esters formed from carboxylic acids and alcohols.
5. Is methyl acetate polar or nonpolar?
Methyl acetate is a moderately polar molecule due to the presence of the carbonyl (C=O) group. Although it contains polar C=O and C–O bonds, it does not form hydrogen bonds with itself because it lacks an O–H bond. As a result, it has moderate solubility in water and is widely used as a polar aprotic solvent in organic chemistry.
6. What are the physical properties of methyl acetate?
Methyl acetate is a colorless, volatile liquid with a fruity odor and low boiling point. Key physical properties include:
- Boiling point: about 57°C
- Molar mass: 74.08 g·mol-1
- Density: about 0.93 g·cm-3 at 20°C
- Moderate solubility in water
7. What happens when methyl acetate undergoes hydrolysis?
Methyl acetate undergoes hydrolysis to form acetic acid and methanol. In acidic conditions, the balanced reaction is:
CH3COOCH3(l) + H2O(l) ⇌ CH3COOH(aq) + CH3OH(aq)
- This is the reverse of esterification.
- In basic conditions (saponification), the reaction forms acetate ion and methanol.
8. What are the common uses of methyl acetate?
Methyl acetate is mainly used as an industrial solvent in coatings, paints, adhesives, and nail polish removers. Its applications include:
- Solvent for resins and lacquers
- Intermediate in organic synthesis
- Extraction solvent in chemical processes
9. What is the difference between methyl acetate and ethyl acetate?
The main difference between methyl acetate and ethyl acetate is the alkyl group attached to the ester functional group.
- Methyl acetate: CH3COOCH3
- Ethyl acetate: CH3COOCH2CH3
10. How do you calculate the percentage composition of methyl acetate?
The percentage composition of methyl acetate is calculated using its molar mass (74.08 g·mol-1) and the mass contribution of each element.
- %C = (36.03 / 74.08) × 100 ≈ 48.6%
- %H = (6.05 / 74.08) × 100 ≈ 8.2%
- %O = (32.00 / 74.08) × 100 ≈ 43.2%
