Chemistry in junior high school acid and alkali salts, the encyclopedia of acid and alkali salts in

This type of question is called inference, and the basis of doing the question is to be familiar with the properties of substances that are commonly tested, including physical properties and chemical properties, physical properties mainly remember the color state of the substance, and the chemical properties remember what the substance reacts with. For example, there is a black solid a, and the black solids we know are manganese dioxide, copper oxide, ferric tetroxide, carbon, and iron powder, so that the inference can be narrowed.

The acid-base neutralization reaction occurs to produce salt and water. Acid refers to compounds in which all cations produced during ionization are hydrogen ions; Base refers to a compound in which all the anions produced during ionization are hydroxide ions; Salts are compounds that ionize to form metal cations (or NH4) and acid ions.

A middle school junior high school students in the chemistry laboratory to do acid, salt, alkali chemical properties of the experiment used dilute hydrochloric acid, caustic soda, soda ash, barium chloride four colorless solutions, after the experiment teacher called A, B two small sit to test the composition of the waste liquid, in which group A students with pH test paper to measure the waste liquid pH 7, then group A inferred that there must be a solute for ———

If group B adds hydrochloric acid dropwise to the waste liquid and finds that bubbles are generated, then group B infers that there must be ——— in the waste liquid and there may be ———

In order to prove the possible ingredients, students in Group B are asked to complete the following blanks.

A small amount of waste liquid is added to the excess ——— to remove the ——— in it

Then phenolphthalein is added to the waste liquid, and the phenomenon is ——— indicating that there must be no such substance.

Answer: A must have dilute hydrochloric acid, (only dilute hydrochloric acid is acidic among the four substances) B must have soda ash and may have caustic soda (there can be no dilute hydrochloric acid and barium chloride if there is soda ash, if there is gas or precipitation, it is impossible to coexist).

BaCl2 goes out of which soda ash.

Phenolphthalein does not change color.

Please be clear:

Is that the case?

Example: Copper sulfate: The following chemical formulas are enantiographed with the name (or common name) The correct one is ( ) a naoh caustic soda sodium hydroxide b naco3 caustic soda sodium bicarbonate c cao hydrated lime calcium oxide d cuso4 malachite if yes, please let me know, I'm giving it to you.

Summary. Hydrochloric acid (HCl) is dilute and concentrated, remember that concentrated hydrochloric acid is volatile, hydrochloric acid is a strong acid, then sulfuric acid (H2SO4) is a strong acid, and carbonic acid (H2CO3) is a weak acid.

Hydrochloric acid (HCl) is dilute and concentrated, remember that concentrated hydrochloric acid is volatile, hydrochloric acid is a strong acid, then sulfuric acid (H2SO4) is a strong acid, and carbonic acid (H2CO3) is a weak acid.

Sodium hydroxide (Naoh) is a strong base, barium hydroxide [Ba(OH)2] is also a strong base, and potassium hydroxide (KOH) is a strong base. As for salt, there will be more salt, nothing is often uncommon, such as carbonate (containing carbonic acid such as K2CO3), barium chloride (BaCl2), silver chloride precipitate (AGCL), together with some salts containing nitrate.

Acids: The cations produced during ionization are all hydrogen ion compounds, called acids such as: H2SO4 (sulfuric acid), HCl (hydrochloric acid), HNO3 (nitric acid).

Alkali: The anions produced during ionization are all compounds of hydroxide ions, called alkalis such as: NaOH (sodium hydroxide), KOH (potassium hydroxide), NH3·H2O (ammonia, also called ammonia monohydrate).

Salt: Compounds that produce metal cations (or NH4) and acid ions when ionized, called salts such as: Na2CO3 (sodium carbonate), CuSO4 (copper sulfate), NH4NO3 (ammonium nitrate).