<!-- To obtain a blank version of this page, type subst:chembox supplement inside of double curly braces, , and save the page -->
This page provides supplementary chemical data on formic acid. <!-- replace with proper wikilink -->
== Material Safety Data Sheet == <!-- KEEP this header, it is linked to from the infobox on the main article page -->
The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet (MSDS) for this chemical from a reliable source and follow its directions.
- MSDS from FLUKA in the SDSdata.org database
- Science Stuff
== Structure and properties == <!-- KEEP this header, it is linked to from the infobox on the main article page -->
{| border="1" cellspacing="0" cellpadding="3" style="margin: 0 0 0 0.5em; background: #FFFFFF; border-collapse: collapse; border-color: #C0C090;"
! | Structure and properties
|-
| Index of refraction, n<sub>D</sub>
| 1.3714 at 20 °C <!-- Please omit if not applicable -->
|-
| Abbe number
|? <!-- Please omit if not applicable -->
|-
| Dielectric constant, ε<sub>r</sub>
| 58.5 ε<sub>0</sub> at 16 °C<br />measured at 400 MHz <!-- Please omit if not applicable -->
|-
| Bond strength
| ? <!-- Specify which bond. Please omit if not applicable -->
|-
| Bond length
| C=O bond: 123 pm<br />C–OH bond: 136 pm <!-- Specify which bond. Please omit if not applicable -->
|-
| Bond angle
| ? <!-- Specify which angle, e.g. Cl-P-O. Please omit if not applicable -->
|-
| Magnetic susceptibility
| ? <!-- Please omit if not applicable -->
|-
| Surface tension
| 37.67 dyn/cm at 20 °C
|-
| Viscosity
|
{|
| 2.2469 mPa·s || at 10 °C
|-
| 1.7844 mPa·s || at 20 °C
|-
| 1.2190 mPa·s || at 40 °C
|-
| 0.5492 mPa·s || at 100 °C
|}
|-
|}
== Thermodynamic properties == <!-- KEEP this header, it is linked to from the infobox on the main article page -->
{| border="1" cellspacing="0" cellpadding="6" style="margin: 0 0 0 0.5em; background: #FFFFFF; border-collapse: collapse; border-color: #C0C090;"
! | Phase behavior
|-
| Triple point
| 281.40 K (8.25 °C), 2.2 kPa
|-
| Critical point
| 588 K (315 °C), 5.81 MPa
|-
| Std enthalpy change<br />of fusion, Δ<sub>fus</sub>H<sup><s>o</s></sup>
| +12.68 kJ/mol
|-
| Std entropy change<br />of fusion, Δ<sub>fus</sub>S<sup><s>o</s></sup>
| +45.05 J/(mol·K) at 8.25 °C
|-
| Std enthalpy change<br />of vaporization, Δ<sub>vap</sub>H<sup><s>o</s></sup>
| +23.1 kJ/mol
|-
| Std entropy change<br />of vaporization, Δ<sub>vap</sub>S<sup><s>o</s></sup>
| +61.8 J/(mol·K)
|-
! | Solid properties
|-
| Std enthalpy change<br />of formation, Δ<sub>f</sub>H<sup><s>o</s></sup><sub>solid</sub>
| ? kJ/mol
|-
| Standard molar entropy,<br />S<sup><s>o</s></sup><sub>solid</sub>
| ? J/(mol K)
|-
| Heat capacity, c<sub>p</sub>
| 74.5 J/(mol K) at –22 °C<br />82.8 J/(mol K) at 0 °C
|-
! | Liquid properties
|-
| Std enthalpy change<br />of formation, Δ<sub>f</sub>H<sup><s>o</s></sup><sub>liquid</sub>
| –425.5 kJ/mol
|-
| Standard molar entropy,<br />S<sup><s>o</s></sup><sub>liquid</sub>
| 129.0 J/(mol K)
|-
| Enthalpy of combustion, Δ<sub>c</sub>H<sup><s>o</s></sup>
| –254.6 kJ/mol
|-
| Heat capacity, c<sub>p</sub>
| 101.3 J/(mol K) at 20–100 °C
|-
! | Gas properties
|-
| Std enthalpy change<br />of formation, Δ<sub>f</sub>H<sup><s>o</s></sup><sub>gas</sub>
| –362.6 kJ/mol
|-
| Standard molar entropy,<br />S<sup><s>o</s></sup><sub>gas</sub>
| 251.0 J/(mol K)
|-
| Heat capacity, c<sub>p</sub>
| 45.68 J/(mol K) at 25 °C
|}
Vapor pressure of liquid
{| border="1" cellspacing="0" cellpadding="6" style="margin: 0 0 0 0.5em; background: white; border-collapse: collapse; border-color: #C0C090;"
| | P in mm Hg || 1 || 10 || 40 || 100 || 400 || 760
|-
| | T in °C || –20.0<sub>(s)</sub> || 2.1<sub>(s)</sub> || 24.0 || 43.8 || 80.3 || 100.6
|}
Table data obtained from CRC Handbook of Chemistry and Physics, 44th ed. The "(s)" notation indicates temperature of solid/vapor equilibrium. Otherwise the data is temperature of liquid/vapor equilibrium.
thumb|817px|left|log<sub>10</sub> of formic acid vapor pressure. Uses formula: <math>\scriptstyle \log_{10} P_{mmHg} = 6.94459 - \frac {1295.26} {218.0+T}</math> obtained from Lange's Handbook of Chemistry, 10th ed.
Distillation data
{| border="1" cellspacing="0" cellpadding="6" style="margin: 0 0 0 0.5em; background: white; border-collapse: collapse; border-color: #C0C090;"
| bgcolor="#D0D0D0" align="center" colspan="3" | Vapor-liquid Equilibrium for Formic acid/Water<br />P = 760 mmHg
|-
! rowspan="2" | BP<br />Temp.<br />°C
! colspan="2" | % by mole water
|-
! liquid !! vapor
|-
| 102.3 || 4.05 || 2.45
|-
| 104.6 || 15.5 || 10.2
|-
| 105.9 || 21.8 || 16.2
|-
| 107.1 || 32.1 || 27.9
|-
| 107.6 || 40.9 || 40.2
|-
| 107.6 || 41.1 || 40.5
|-
| 107.6 || 46.4 || 48.2
|-
| 107.1 || 52.2 || 56.7
|-
| 106.0 || 63.2 || 71.8
|-
| 104.2 || 74.0 || 83.6
|-
| 102.9 || 82.9 || 91.7
|-
| 101.8 || 90.0 || 95.1
|}
== Spectral data == <!-- KEEP this header, it is linked to from the infobox on the main article page -->
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! | UV-Vis
|-
| λ<sub>max</sub>
| ? nm
|-
| Extinction coefficient, ε
| ?
|-
! | IR
|-
| Major absorption bands
| ? cm<sup>−1</sup>
|-
! | NMR
|-
| Proton NMR <!-- Link to image of spectrum -->
|
|-
| Carbon-13 NMR <!-- Link to image of spectrum -->
|
|-
| Other NMR data <!-- Insert special data e.g. <sup>19</sup>F chem. shifts, omit if not used -->
|
|-
! | MS
|-
| Masses of <br />main fragments
| <!-- Give list of major fragments -->
|}
Safety data
<!-- Here is a table of data; skip past it to edit the text. -->
{| align="left" border="1" cellspacing="0" cellpadding="3" style="margin: 0 0 0 0.5em; background: #FFFFFF; border-collapse: collapse; border-color: #C0C090;"
! | Formic acid
|-
| EINECS number
| 200-579-1
|-
| | Safety data <!-- INDEX n° 607-001-00-0 -->
|-
| EU classification
| Corrosive (C)
|-
| PEL
| 5 ppm (9 mg/m<sup>3</sup>)
|-
| IDLH
| 30 ppm
|-
| Autoignition temperature
| 520 °C
|-
| Explosive limits
| 18–51%
|}