2-Butanol is a colorless, flammable liquid with a sweet odor. It is commonly used as a solvent and in the production of chemicals such as methyl ethyl ketone and butyl acetate.
| IUPAC Name | 2-Butanol |
| Molecular Formula | C4H10O |
| CAS Number | 78-92-2 |
| Synonyms | sec-Butyl alcohol, 2-Butyl alcohol, Butan-2-ol, Ethylmethylcarbinol |
| InChI | InChI=1S/C4H10O/c1-3-4(2)5/h4-5H,3H2,1-2H3 |
2-Butanol Properties
2-Butanol Formula
The chemical formula of 2-Butanol is C4H10O, which indicates that it contains four carbon atoms, ten hydrogen atoms, and one oxygen atom. It is an isomer of butanol and has a structural formula of CH3CH(OH)CH2CH3. The “2” in the name of the compound signifies the position of the hydroxyl group on the carbon chain.
2-Butanol Molar Mass
The molar mass of C4H10O is 74.12 g/mol. This value can be obtained by adding the atomic masses of all the atoms in the compound, which are 12.01 g/mol for carbon, 1.01 g/mol for hydrogen, and 16.00 g/mol for oxygen. The molar mass is an important property of C4H10O as it is used to calculate the amount of the compound required in chemical reactions.
2-Butanol Boiling Point
The boiling point of C4H10O is 99.5 °C (211.1 °F) at standard pressure (1 atm). This is the temperature at which the liquid state of the compound changes into the gaseous state. The boiling point of C4H10O is higher than that of butane (−0.5 °C) and butene (−6.3 °C) due to its hydrogen bonding and molecular weight.
2-Butanol Melting Point
The melting point of C4H10O is −114.7 °C (−174.5 °F). This is the temperature at which the solid state of the compound changes into the liquid state. The melting point of C4H10O is lower than that of butane (−138.4 °C) and butene (−185.3 °C) due to its branched structure and hydrogen bonding.
2-Butanol Density g/mL
The density of C4H10O is 0.809 g/mL at 25 °C (77 °F). This value indicates the mass of the compound per unit volume of the substance. The density of C4H10O is higher than that of butane (0.588 g/mL) and butene (0.587 g/mL) due to its molecular weight and intermolecular forces.
2-Butanol Molecular Weight
The molecular weight of C4H10O is 74.12 g/mol. It is the sum of the atomic weights of all the atoms in a molecule of the compound. The molecular weight is used to calculate other properties of the compound, such as molar mass, boiling point, and density.
2-Butanol Structure
The structure of C4H10O is characterized by a branched carbon chain with a hydroxyl group attached to the second carbon atom. It is a primary alcohol with a chiral center, which means that it exists as two stereoisomers, (R)-C4H10O and (S)-C4H10O. The compound has a three-dimensional structure due to the tetrahedral arrangement of the carbon and oxygen atoms around the hydroxyl group.
2-Butanol Solubility
C4H10O is a polar compound and is partially soluble in water. The solubility of C4H10O in water is 80 g/L at 25 °C (77 °F). The compound is more soluble in organic solvents such as ethanol, ether, and acetone. The solubility of C4H10O is influenced by factors such as temperature, pressure, and the nature of the solvent.
| Appearance | Clear liquid |
| Specific Gravity | 0.810 g/mL at 25 °C (77 °F) |
| Color | Colorless |
| Odor | Characteristic |
| Molar Mass | 74.12 g/mol |
| Density | 0.809 g/mL at 25 °C (77 °F) |
| Melting Point | −114.7 °C (−174.5 °F) |
| Boiling Point | 99.5 °C (211.1 °F) at 1 atm pressure |
| Flash Point | 39 °C (102 °F) closed cup |
| Water Solubility | 80 g/L at 25 °C (77 °F) |
| Solubility | Soluble in ethanol, ether, and acetone |
| Vapour Pressure | 8.7 mmHg at 25 °C (77 °F) |
| Vapour Density | 2.6 (air = 1) |
| pKa | 16 |
| pH | 7.0-8.5 |
2-Butanol Safety and Hazards
C4H10O is considered to be a relatively safe chemical when handled properly. However, exposure to high concentrations can cause irritation to the eyes, skin, and respiratory tract. It may also cause headaches, dizziness, and nausea. Ingestion of C4H10O can cause gastrointestinal irritation and possible central nervous system depression. In addition, C4H10O is flammable and can pose a fire hazard. It should be stored in a cool, dry, well-ventilated area away from sources of ignition. Proper personal protective equipment, such as gloves and goggles, should be worn when handling this chemical. Spills should be cleaned up promptly using appropriate procedures.
| Hazard Symbols | F, Xi |
| Safety Description | Keep away from heat/sparks/open flames/hot surfaces. Wear protective gloves/protective clothing/eye protection/face protection. IF ON SKIN (or hair): Remove/Take off immediately all contaminated clothing. Rinse skin with water/shower. IF INHALED: Remove victim to fresh air and keep at rest in a position comfortable for breathing. IF SWALLOWED: Rinse mouth. Do NOT induce vomiting. Call a POISON CENTER or physician if you feel unwell. |
| UN IDs | UN1120 |
| HS Code | 2905.13.00 |
| Hazard Class | 3 – Flammable liquids |
| Packing Group | III |
| Toxicity | LD50 (oral, rat): 4.6 g/kg; LC50 (inhalation, rat): 2100 ppm/4 h |
2-Butanol Synthesis Methods
Several methods can synthesize C4H10O.
One method involves the reduction of acetone using sodium borohydride in the presence of a nickel or palladium catalyst. The reaction produces a mixture of C4H10O and its isomer, isobutanol, which can be separated through fractional distillation.
Another method involves the hydration of 1-butene using sulfuric acid as a catalyst. The reaction forms a mixture of C4H10O and its isomers, but the desired C4H10O can be separated through fractional distillation.
The process of Reppe chemistry involves using a palladium or nickel catalyst to react acetylene with formaldehyde and water, resulting in the formation of vinyl alcohol. This reaction further leads to the synthesis of C4H10O. The vinyl alcohol then undergoes hydrogenation to form C4H10O.
Another method of synthesizing C4H10O involves the hydrogenation of crotonaldehyde in the presence of a nickel catalyst. The reaction produces a mixture of C4H10O and its isomer, but the desired C4H10O can be isolated through fractional distillation.
2-Butanol Uses
C4H10O has a variety of applications in different industries. Some of its uses are:
- Solvent: Used as a solvent in the manufacturing of resins, varnishes, and coatings. Also used as a solvent for cellulose ethers and esters.
- Fuel: Used as a biofuel additive due to its low toxicity and high energy content. It has been found to have a higher combustion efficiency than ethanol and is being studied as a potential alternative to gasoline.
- Chemical Intermediate: Used as a starting material for the production of other chemicals such as methyl ethyl ketone, methyl isobutyl ketone, and diisobutylene.
- Perfume and Fragrance: Used as a fragrance and flavoring agent in the production of perfumes, soaps, and other personal care products.
- Laboratory reagent: Used as a solvent and reagent in organic chemistry experiments.
- Cleaning agent: Used as a cleaning agent in industrial and household cleaning products.
- Printing ink: Also used as a solvent in the production of printing inks.
Questions:
Q: What carbonyl compound and Grignard reagent could be used to prepare 2-butanol?
A: The carbonyl compound that could be used to prepare C4H10O is butanal (also known as n-butyraldehyde) and the Grignard reagent that could be used is ethyl magnesium bromide. The reaction between butanal and ethyl magnesium bromide produces C4H10O as the final product.
Q: Is 2-butanol polar?
A: Yes, C4H10O is polar. It contains a hydroxyl (-OH) group, which is a polar functional group that makes the molecule polar.
Q: Is 2-butanol soluble in water?
A: Yes, C4H10O is partially soluble in water. The polar hydroxyl group in C4H10O allows it to form hydrogen bonds with water molecules, which makes it somewhat soluble in water.
Q: Does 2-butanol have hydrogen bonding?
A: Yes, C4H10O can form hydrogen bonds. The hydroxyl (-OH) group in C4H10O can form hydrogen bonds with other polar molecules containing hydrogen bonding sites, such as water.