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Reader task: a researcher, lab technician or student needs the density of ethyl acetate with its temperature, needs to convert between volume and mass for a calculation, and needs to know which way it separates from water.
Short answer: what is the density of ethyl acetate?
Ethyl acetate (CAS 141-78-6) has a density of 0.9003 g/mL (0.9003 g/cm³) at 20 °C, so it is lighter than water and floats on it. Sources that print 0.9 are rounding. A 100 mL volume weighs about 90.0 g. This page is a bench reference, not a safety instruction.
Definition and scope
Ethyl acetate, CH3COOC2H5 (molar mass 88.1 g/mol), is a colourless liquid with a characteristic odour. Density is mass per unit volume and it changes with temperature, so a density quoted without a temperature is incomplete. This page treats it as a laboratory solvent and reagent, with values from PubChem (collating HSDB, CAMEO Chemicals, PAC, NIOSH, OSHA and JECFA), the NIST Chemistry WebBook, ILO/WHO International Chemical Safety Card (ICSC) 0367 and the Burdick and Jackson solvent tables published by Louisiana State University.
Ethyl acetate density: what the sources report
| Source | Reported value | Temperature stated? |
|---|---|---|
| PubChem, HSDB entry | 0.9003 g/cm³ | 20 °C |
| PubChem, PAC Chemical Database (US DOE) | 0.9003 | 20 °C |
| PubChem, CAMEO Chemicals (USCG, 1999) | 0.902 | 68 °F (20 °C) |
| PubChem, JECFA (food-additive specification) | 0.894–0.898 | Not shown in the entry |
| ICSC 0367, OSHA, NIOSH | 0.9 (relative density, water = 1) | Not stated |
The 0.9003 and 0.902 figures are the same quantity at 20 °C from different compilations and differ by about 0.2%. The one-decimal 0.9 differs from 0.9003 by 0.03%, about 0.3 g per litre. Quote the value together with its temperature and source.
Worked example: converting between volume and mass
Calculated from 0.9003 g/mL at 20 °C:
- 100 mL × 0.9003 g/mL = 90.03 g.
- 250 g ÷ 0.9003 g/mL = 277.7 mL.
- A 500 mL volume of solvent weighs about 450.1 g, before the weight of the container.
- 100 mL is 90.03 g ÷ 88.1 g/mol = 1.022 mol, so neat ethyl acetate is roughly 10.2 mol/L.
These apply at 20 °C. At another temperature, use the density reported for that temperature.
Ethyl acetate properties on one card
| Property | Value | Source |
|---|---|---|
| Boiling point, 1 atm | 77.1 °C (NIST: 350.2 ± 0.2 K) | NIST; ICSC 0367 (77 °C); PubChem PAC (77.11 °C) |
| Melting (freezing) point | −83.8 °C (ICSC: −84 °C) | PubChem HSDB and PAC; ICSC 0367 |
| Vapour pressure | 10 kPa at 20 °C; 93.2 mmHg at 25 °C | ICSC 0367; PubChem HSDB |
| Viscosity | 0.45 cP at 20 °C; 0.423 mPa·s at 25 °C | Burdick and Jackson via LSU; PubChem HSDB |
| Refractive index | 1.3723 at 20 °C (D line) | PubChem HSDB |
| Polarity index P′ | 4.4 | Burdick and Jackson via LSU |
| Solubility in water | 8.7 g/100 mL at 20 °C | ICSC 0367 |
| Vapour density (air = 1) | 3.0 | ICSC 0367 |
Ethyl acetate boiling point and boiling under vacuum
NIST gives a normal boiling point of 350.2 ± 0.2 K (77.05 °C), the average of 58 of 72 collected values. For reduced pressure, NIST lists Antoine constants for ethyl acetate, log10(P/bar) = A − B/(T + C) with T in kelvin: A = 4.22809, B = 1245.702, C = −55.189, valid from 288.73 to 348.98 K (15.6 to 75.8 °C), from Polák and Mertl (1965). Solving for T gives the table below. These are our calculated values from the NIST constants, rounded to 0.1 °C, not measured data.
| Pressure | Calculated boiling point |
|---|---|
| 500 mbar | 57.1 °C |
| 300 mbar | 44.2 °C |
| 200 mbar | 34.9 °C |
| 100 mbar | 20.3 °C |
On a rotary evaporator the boiling temperature at the vacuum you apply, not the 77 °C atmospheric value, governs how the solvent behaves; see our guide to the rotary evaporator. The fit is only valid inside its stated range. For a comparison with another common solvent, see ethanol boiling point.
Ethyl acetate vapor pressure
ICSC 0367 lists 10 kPa at 20 °C and CAMEO lists 73 mmHg at 20 °C. The NIST fit above gives 9.8 kPa at 20 °C, consistent with both, and 16.0 kPa at 30 °C and 25.1 kPa at 40 °C (our calculation).
Ethyl acetate polarity and polarity index
The Burdick and Jackson polarity index P′ is described as a relative measure of how strongly a solvent interacts with polar test solutes. Ethyl acetate sits mid-scale, well above hexane and below acetone and methanol.
| Solvent | Polarity index P′ |
|---|---|
| Hexane | 0.1 |
| Dichloromethane | 3.1 |
| Ethyl acetate | 4.4 |
| Acetone | 5.1 |
| Methanol | 5.1 |
| Water | 10.2 |
That mid-scale placement is the context for choosing it in a solvent system; see column chromatography solvent selection.
Ethyl acetate miscibility with water
ICSC 0367 gives a solubility in water of 8.7 g/100 mL at 20 °C (poor). HSDB adds that ethyl acetate absorbs water (up to 3.3% wt/wt) and forms an azeotrope with water (6.1% wt/wt) that boils at 70.4 °C, so the two are only partly miscible.
Related esters: methyl acetate and ethyl lactate
| Compound | Density at 20 °C (g/cm³) | Boiling point, 760 mmHg | Compared with water |
|---|---|---|---|
| Ethyl acetate | 0.9003 | 77.1 °C | Less dense; floats |
| Methyl acetate | 0.9342 | 56.7 °C | Less dense; floats |
| Ethyl lactate | 1.0328 | 154 °C | Denser; sinks |
Source: PubChem HSDB entries; CAMEO Chemicals for the water comparison.
What is the density of methyl acetate?
0.9342 g/cm³ at 20 °C (HSDB), about 4% denser than ethyl acetate and still lighter than water. CAMEO lists 0.927 at 68 °F and the PAC database 0.92438 at 25 °C.
What is the density of ethyl lactate?
1.0328 g/cm³ at 20 °C (HSDB), so unlike the acetates it is denser than water and sinks. CAMEO lists 1.03 at 68 °F, and the PAC entry for ethyl (S)-lactate 1.042 at 25 °C.
Where it matters in the lab
What is heavier, ethyl acetate or water?
Water. Water is about 1 g/mL and ethyl acetate is 0.9003 g/mL at 20 °C; CAMEO describes it as less dense than water and says it will float. With a water solubility of 8.7 g/100 mL, an ethyl acetate and water mixture separates into two layers with the ethyl acetate on top. Layer order follows each solvent’s own density: ethyl lactate, for comparison, is denser than water.
Why is ethyl acetate hazardous?
The main hazard is fire. ILO/WHO ICSC 0367 (April 2014) gives the following:
- GHS signal word DANGER: highly flammable liquid and vapour; may cause drowsiness or dizziness.
- Flash point −4 °C (closed cup), auto-ignition temperature 427 °C, explosive limits 2.0 to 12.8 vol% in air. Because the flash point is below ordinary room temperature, an ignitable vapour can form without heating.
- The vapour is heavier than air and may travel along the ground, so distant ignition is possible.
- It attacks rubber and some forms of plastic (see our chemical resistance chart for plastics), reacts with strong oxidants, and reacts violently with strong acids and strong bases.
- It is mildly irritating to the eyes and respiratory tract, may affect the central nervous system, and defats the skin. Listed limits: TLV 400 ppm TWA; EU-OEL 200 ppm TWA, 400 ppm STEL.
- Storage: fireproof, separated from strong oxidants, strong bases and strong acids.
For storage rules see flammable liquid storage cabinet requirements, and for how to read the supplier’s sheet see how to read a safety data sheet. Always follow your own safety data sheet and site procedures.
Common misunderstandings
- A density without a temperature is incomplete: 0.9003 g/mL applies at 20 °C.
- “0.9” is a rounded relative density, not a different measurement.
- The liquid is lighter than water but its vapour is heavier than air.
- The 77 °C boiling point applies at 1 atm; under vacuum it boils far lower.
FAQ
What is the density of ethyl acetate?
0.9003 g/mL at 20 °C, so 100 mL weighs about 90.0 g.
What is heavier, ethyl acetate or water?
Water is heavier. Ethyl acetate is less dense than water and floats on it.
Why is ethyl acetate hazardous?
It is a highly flammable liquid with a flash point of −4 °C, its vapour can travel along the ground, and it can cause drowsiness or dizziness (ICSC 0367).
What is the density of methyl acetate?
0.9342 g/cm³ at 20 °C, slightly denser than ethyl acetate and lighter than water.
What is the density of ethyl lactate?
1.0328 g/cm³ at 20 °C, denser than water.
Sources
- PubChem, Ethyl acetate (CID 8857), density, boiling point, melting point, vapor pressure, refractive index and viscosity sections: pubchem.ncbi.nlm.nih.gov/compound/8857, read 2026-11-07.
- PubChem, Methyl acetate (CID 6584) and Ethyl lactate (CID 7344), density and boiling point sections: CID 6584, CID 7344, read 2026-11-07.
- NIST Chemistry WebBook, ethyl acetate (CAS 141-78-6), phase change data: webbook.nist.gov, read 2026-11-07.
- ILO/WHO ICSC 0367, Ethyl acetate (April 2014): inchem.org, and ICSC 0507, Methyl acetate: inchem.org, read 2026-11-07.
- Louisiana State University, Burdick and Jackson solvent tables: polarity index and viscosity, read 2026-11-07.
