Question

в одной пробирке находится HCL, в другой K2SO4. Распознайте вещества двумя способами.

Answer 1

 

1. HCl + AgNO3 = AgCl + HNO3

                           осадок

 

2. K2SO4 + BaCl2 = BaSO4 + 2KCl

                                осадок

Answer 2

Identifying the Substances in the Test Tubes

To identify the substances in the two test tubes, one containing HCl and the other containing K2SO4, there are two possible methods that can be used.

Method 1: Chemical Reactions

One way to identify the substances is by performing chemical reactions with known reagents and observing the resulting reactions. Here are the reactions that can be performed:

1. HCl (Hydrochloric Acid): - Reaction with silver nitrate (AgNO3): HCl reacts with AgNO3 to form a white precipitate of silver chloride (AgCl). - Reaction with sodium carbonate (Na2CO3): HCl reacts with Na2CO3 to produce carbon dioxide gas (CO2), water (H2O), and sodium chloride (NaCl).

2. K2SO4 (Potassium Sulfate): - Reaction with barium chloride (BaCl2): K2SO4 reacts with BaCl2 to form a white precipitate of barium sulfate (BaSO4). - Reaction with hydrochloric acid (HCl): K2SO4 reacts with HCl to produce potassium chloride (KCl) and sulfuric acid (H2SO4).

By performing these reactions and observing the resulting products, we can determine the substances present in the test tubes.

Method 2: Physical Properties

Another way to identify the substances is by examining their physical properties. Here are some properties that can help distinguish between HCl and K2SO4:

1. HCl (Hydrochloric Acid): - HCl is a colorless liquid with a strong, pungent odor. - It is highly soluble in water, and its solution is acidic. - HCl has a low boiling point of approximately -85 degrees Celsius.

2. K2SO4 (Potassium Sulfate): - K2SO4 is a white crystalline solid. - It is soluble in water, and its solution is neutral. - K2SO4 has a high melting point of approximately 1069 degrees Celsius.

By observing these physical properties, we can differentiate between HCl and K2SO4.

In conclusion, there are two methods to identify the substances in the test tubes: chemical reactions and examination of physical properties. By performing specific reactions and observing the resulting products, or by examining the physical properties of the substances, we can determine whether the test tube contains HCl or K2SO4.

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