Chemistry: Sodium bicarbonate (baking soda)

Sodium bicarbonate, with the formula NaHCO₃, is a weakly alkaline inorganic salt. Therefore, it is also called acid sodium carbonate. Commonly known as baking soda. In the upper left corner of the figure above is the molecular structure of sodium bicarbonate: the black ball is a tetravalent carbon atom that is connected to three oxygen atoms (red balls) by a covalent bond. Oxygen atoms are divalent. The oxygen atom on the right is connected to the carbon atom with a double bond, so it is exactly the four bonds of the carbon atom. The oxygen atom in the lower left also has a bond attached to a hydrogen atom (a smaller white ball), and the hydrogen atom is monovalent. The upper right oxygen atom is left with a bond to connect the monovalent sodium atom (iron gray ball).

The white powder is actually a fine crystal, and under the magnifying glass is a single oblique crystal.

Baking soda is one of the staples of most Chinese homes. First, wheat food to do loose agents; second, there are several kinds of stomach diseases, one is too much stomach acid, stomach pain when taking baking soda, acid and alkali neutralization, it feels more comfortable; third, decontamination, with baking soda to wipe the stolen goods, both physical decontamination (friction of fine grains) and chemical decontamination (reaction with the acidic substances in the stolen goods, the formation of new salts that can be dissolved in water); fourth, cleaning fruits and vegetables, will not leave residues.

Baking soda reacts violently when it comes to acidic substances, breaking down to produce carbon dioxide. If it is a non-toxic and harmless weak acid substance, it is made into soda. In kindergarten, my grandfather taught me to experiment with baking soda and white vinegar. I've always loved doing this chemistry experiment. Because, as long as the proportion is appropriate, the experimental effect is still spectacular. At the same time, there is no danger. Children can do this experiment under the guidance of adults to understand what is a chemical change? The generation of new substances is chemical change.

Acetic acid is also known as acetic acid, and the molecular formula is CH3COOH. On the upper right of the image above is acetic acid, whose molecular structure has been mentioned in the previous article "Chemistry: Rice Vinegar and Acetic Acid (Acetic Acid, Glacial Acetic Acid, Glacial Acetic Acid)". Its reaction with baking soda is:

NaHCO3＋CH3COOH＝CH3COONa＋H2O＋CO2↑

The reaction produces sodium acetate, water, and carbon dioxide. The lower left in the figure above is sodium acetate (that is, sodium acetate), whose molecular structure is very similar to acetic acid, that is, the hydrogen atom on the single bond oxygen atom is replaced by a sodium atom (iron gray ball). In the lower middle are water molecules, and oxygen atoms (red balls) connect two hydrogen atoms (small white balls). On the lower right is carbon dioxide, a carbon atom (black ball) connected to two oxygen atoms, each of which is connected to the carbon atom by a double bond. The up arrow to the right of the reaction equation indicates that carbon dioxide is a gas that escapes after the reaction is generated.

However, soda made from white vinegar and baking soda reaction is not good. Grandpa said that when he was a child, he made soda with baking soda and citric acid. If it is the bayberry season, use bayberry juice and baking soda. How much bayberry juice with how much baking soda, to experiment. More bayberry juice, more acid; more baking soda, astringent. Not sour or astringent, that is, the acidic substances in the bayberry juice are exactly the complete reaction with baking soda.