Sodium bicarbonate (chemical formula: NaHCO), commonly known as baking soda, soda ash, baking soda (Hong Kong, Taiwan), heavy caustic soda, baking alkali, etc., is a small white crystal with a lower solubility in water than soda.
Sodium bicarbonate is a white alkaline powder that is easily soluble in water. After combining with water, it starts to release carbon dioxide CO2. It reacts faster in acidic liquids (such as juice). As the ambient temperature increases, the released gas acts faster.
Sodium bicarbonate will remain after use. If used too much, the finished product will have an alkaline smell.
Sodium bicarbonate aqueous solution is weakly alkaline, commonly known as baking soda and baking alkali.
Collapse and edit this section Chemical Properties
Easy to decompose when heated. Decomposes slowly in moist air. The reaction starts to produce CO? at about 50°C, and all turns into sodium carbonate at 100°C. It decomposes rapidly in weak acid. Its aqueous solution begins to decompose into carbon dioxide and sodium carbonate at 20°C, and completely decomposes at the boiling point. It is soluble in 10 parts of water at 25℃, soluble in 12 parts of water at about 18℃, and insoluble in ethanol. The unstirred solution made of cold water only shows a slightly alkaline reaction to the phenolphthalein test paper. When placed or the temperature is raised, its alkalinity increases. The pH value of a freshly prepared 0.1mol/L aqueous solution at 25°C is 8.3. Low toxicity, LD50 (rat, oral) 4420mg/kg.
Folding and acid reaction
Reaction with HCl: NaHCO?+HCl ====NaCl+H?O+CO?↑
With CH?COOH Reaction: NaHCO?+CH?COOH====CH?COONa+H?O+CO?↑
Folding and alkali reaction
Reaction with sodium hydroxide: NaHCO?+ NaOH==== Na?CO?+ H?O
Reaction with calcium hydroxide: The dosage of sodium bicarbonate should be divided into excessive and small amounts.
A small amount: NaHCO?+ Ca(OH)?==== CaCO?↓+ NaOH + H?O
Excess: 2NaHCO?+ Ca(OH)?=== = Na?CO?+ CaCO?↓+ 2H?O
Folding and salt reaction
Reaction with CuSO?: generate basic copper carbonate and sodium sulfate, water and carbon dioxide
p>Folding hydrolysis
With aluminum chloride: 3NaHCO?+ AlCl?====Al(OH)?↓+ 3CO?↑+ 3NaCl
With aluminum sulfate Double hydrolysis: Al?(SO?)?+6NaHCO?==3Na?SO?+2Al(OH)?↓+6CO?↑
Folding and heating
Thermal decomposition: 2NaHCO ?==△== Na?CO?+ H?O + CO?↑
Folding ionization
Sodium bicarbonate ionization equation NaHCO?=Na+?+ HCO?﹣
Folding Safety Terms
Avoid contact with skin and eyes.
Fold edit this section Physical and chemical introduction
Fold chemical formula
NaHCO?
Fold relative molecular mass
84.01
Folding properties
Natural baking soda powder, edible baking soda NaHCO?
Properties: White powder or monoclinic crystalline powder, odorless, salty, Easily soluble in water, but less soluble than sodium carbonate in water, insoluble in ethanol, and the aqueous solution is slightly alkaline. Easily decomposes when heated. Decomposes slowly in moist air.
It begins to lose carbon dioxide at about 50℃, and turns into sodium carbonate at 100℃. It decomposes rapidly in weak acid. Its aqueous solution begins to decompose into carbon dioxide and sodium carbonate at 20°C, and completely decomposes at the boiling point. It is soluble in 10 parts of water at 25℃, soluble in 12 parts of water at about 18℃, and insoluble in ethanol. The unstirred solution made of cold water only shows a slightly alkaline reaction to the phenolphthalein test paper. When placed or the temperature is raised, its alkalinity increases. The pH value of a freshly prepared 0.1mol/L aqueous solution at 25°C is 8.3. Low toxicity, LD50 (rat, oral) 4420mg/kg.
Fold and store
Dry, protected from light, and sealed.
Folding purposes
Analytical reagents. Organic synthesis.
Pharmaceutical (to treat hyperacidity). Leavening agent (for baking pastries). Extinguishing media (foam or dry powder).
The pH is greater than 7, which is alkaline, but does not contain OH-, and is not an alkali, but an acid carbonate (bicarbonate).