Formic acid can cause combustion and explosion when exposed to open flame and high heat. Strong oxidant, strong alkali and active metal powder. High concentrations of formic acid tend to freeze in winter. The molecular composition of formic acid is insoluble in hydrocarbons and is bound by hydrogen bonds. The critical temperature is 306.8. It can react with strong oxidants.

易燃。可與水、乙醇、乙醚和甘油自由混溶，可與大多數極性有機溶劑混溶，并可溶于烴類。

Flammable. It is free miscible with water, ethanol, ether and glycerin, miscible with most polar organic solvents, and soluble in hydrocarbons.

相對密度(d204)為1.220。折射率是1.3714。燃燒熱為254.4kJ/mol，臨界溫度為306.8，臨界壓力為8.63MPa.閃點68.9(開杯)。密度為1.22，相對蒸汽密度為1.59(空氣=1)，飽和蒸汽壓(24)為5.33 kPa。

The relative density (d204) was 1.220. The refractive index is 1.3714. The combustion heat is 254.4 kJ / mol, the critical temperature is 306.8, the critical pressure is 8.63 MPa, and the flash point is 68.9 (open cup). The density is 1.22, the relative vapor density is 1.59 (air = 1), and the saturated vapor pressure (24) is 5.33 kPa.

高濃度的甲酸在冬天容易結冰。

High concentrations of formic acid tend to freeze in winter.

禁用化合物：強氧化劑、強堿和活性金屬粉末。

Prohibited compounds: strong oxidant, strong base and active metal powder.

危險特性：其蒸氣和空氣形成爆炸性混合物，暴露在明火和高熱下可引起燃燒和爆炸。它能與強氧化劑反應。

Hazard characteristics: its vapor and air form an explosive mixture, which can cause combustion and explosion when exposed to open fire and high heat. It can react with strong oxidants.

溶解性：與水混溶，不溶于烴，與醇混溶。

Solubility: miscible with water, insoluble in hydrocarbon and miscible with alcohol.

在烴類和氣態中，甲酸通過氫鍵以二聚體的形式出現。氣態時，氫鍵導致甲酸氣體與理想氣體狀態方程有較大偏差。液體和固體甲酸由通過氫鍵結合的連續甲酸分子組成。

In hydrocarbons and gases, formic acid appears as dimers through hydrogen bonds. In the gaseous state, hydrogen bonding leads to a large deviation between formic acid gas and ideal gas equation of state. Liquid and solid formic acids consist of continuous molecules of formic acid bound by hydrogen bonds.

這些是甲酸的物理化學性質。明火和高熱引起的燃燒和爆炸。甲酸以氫鍵結合的二聚體形式出現在烴中，具有溶解性。

These are the physicochemical properties of formic acid. Burning and explosion caused by open fire and high heat. Formic acid occurs in hydrocarbons in the form of hydrogen bonded dimers and is soluble.