Formaldehyde is written HCHO. With school atomic masses the molar mass is 30 g/mol. Formaldehyde is the simplest aldehyde and a highly reactive carbonyl compound.
H₂O
WaterNH₃
AmmoniaCO₂
Carbon DioxideH₂O₂
Hydrogen PeroxideSO₂
Sulfur DioxideNO₂
Nitrogen DioxideHCl
Hydrochloric AcidH₂SO₄
Sulfuric AcidHNO₃
Nitric AcidCH₄
MethaneC₂H₆
EthaneC₃H₈
PropaneC₄H₁₀
ButaneC₂H₄
EthyleneC₂H₂
AcetyleneC₆H₆
BenzeneC₇H₈
TolueneC₁₀H₈
NaphthaleneC₆H₁₂
CyclohexaneCH₃OH
MethanolC₂H₅OH
EthanolCH₃COOH
Acetic AcidHCHO
FormaldehydeCH₃COCH₃
AcetoneC₄H₁₀O
Diethyl EtherC₂H₇N
EthylamineC₂H₅NO
AcetamideC₆H₁₂O₆
GlucoseC₆H₁₂O₆
FructoseC₁₂H₂₂O₁₁
SucroseCO(NH₂)₂
UreaC₂₇H₄₆O
CholesterolC₉H₈O₄
AspirinC₈H₉NO₂
AcetaminophenC₁₃H₁₈O₂
IbuprofenC₈H₁₀N₄O₂
CaffeineC₆H₆N₂O
NicotinamideC₆H₈O₆
Ascorbic AcidC₁₆H₁₈N₂O₄S
Penicillin GC₂H₆O₂
Ethylene GlycolC₈H₈
StyreneC₂H₃Cl
Vinyl ChlorideC₃H₅NO
AcrylamideC₆H₁₁NO
CaprolactamLiCl
Lithium chlorideNa₂O
Sodium oxideNaCl
Sodium chlorideMgF₂
Magnesium fluorideAlCl₃
Aluminum chlorideCaO
Calcium oxideCaC₂
Calcium carbideKNO₃
Potassium nitrateMg₃(PO₄)₂
Magnesium phosphateAl₂(SO₄)₃
Aluminum sulfateMg(OH)₂
Magnesium hydroxideNH₄Cl
Ammonium chlorideNH₄OH
Ammonium hydroxideCuO
Copper(II) oxideCu₂O
Copper(I) oxideFeSO₄
Iron(II) sulfateFe₂(SO₄)₃
Iron(III) sulfatePbCO₃
Lead(II) carbonateMgO
Magnesium oxideAl₂S₃
Aluminum sulfideLiF
Lithium fluoride(NH₄)₂S
Ammonium sulfideKF
Potassium fluorideNiCl₂
Nickel(II) chlorideKCN
Potassium cyanideCH₃COONa
Sodium acetateCaCO₃
Calcium carbonateNa₃P
Sodium phosphideBeBr₂
Beryllium bromideFeO
Iron(II) oxideHg₂Cl₂
Mercury(I) chlorideHg(NO₃)₂
Mercury(II) nitrateCH₃COOCu
Copper(I) acetateSiO₂
Silicon dioxideP₄O₁₀
Tetraphosphorus decaoxideN₂O₅
Dinitrogen pentoxideCO
Carbon monoxideHF
Hydrogen fluoridePCl₅
Phosphorus pentachlorideCF₄
Carbon tetrafluorideSF₆
Sulfur hexafluorideNBr₃
Nitrogen tribromideN₂O
Dinitrogen monoxideN₂O₃
Dinitrogen trioxideCS₂
Carbon disulfideCl₂O₇
Dichlorine heptoxideBF₃
Boron trifluorideCCl₄
Carbon tetrachlorideSO₃
Sulfur trioxideSiCl₄
Silicon tetrachlorideP₂S₅
Diphosphorus pentasulfideBCl₃
Boron trichloridePBr₃
Phosphorus tribromideCBr₄
Carbon tetrabromideNF₃
Nitrogen trifluorideOF₂
Oxygen difluorideNCl₃
Nitrogen trichlorideH₂S
Hydrogen sulfidePH₃
PhosphineBeCl₂
Beryllium chlorideHCN
Hydrogen cyanideClF₃
Chlorine trifluorideXeF₂
Xenon difluorideFormaldehyde is the simplest aldehyde and a highly reactive carbonyl compound. It cross-links proteins and is useful in resins and biological fixation.
Properties
Molar mass
30.026 g/mol
Boiling point
−19 °C
pKa (formaldehyde hydrate)
13.5
Hybridization (C)
sp²
WHO classification
Group 1 carcinogen (inhalation)
Uses
Resin manufacturing · Laboratory fixatives · Disinfection chemistry in controlled settings
Molar mass calculation
Masses given in the question come first. When none are given, school values put the total at 30 g/mol.
+
+
= 30 g/mol
HCHO
CH₂O
The same count with periodic-table atomic masses gives 30.026 g/mol.
| Element | Atom count | Contribution (g/mol) | Mass % |
|---|---|---|---|
| Carbon (C) | 1 | 12.011 | 40.0 |
| Hydrogen (H) | 2 | 2.016 | 6.7 |
| Oxygen (O) | 1 | 15.999 | 53.3 |
| Total | 30.026 | 100 |
Common questions
What is formaldehyde?
Formaldehyde is the simplest aldehyde and a highly reactive carbonyl compound. It cross-links proteins and is useful in resins and biological fixation.
What is the formula of formaldehyde?
Formaldehyde is written HCHO. The molecular formula is CH₂O.
What is the molar mass of formaldehyde?
Formaldehyde has a molar mass of 30.026 g/mol from the atomic masses on the periodic table. With school atomic masses the total is 30 g/mol, counting 1 carbon, 2 hydrogen and 1 oxygen.
What is formaldehyde used for?
Formaldehyde is used for resin manufacturing, laboratory fixatives and disinfection chemistry in controlled settings.