Question

Визначити речовини. У двох пронумерованих пробірках містяться розчин барій нітрату Ba(NO 3 ) 2 і амоній нітрату NH 4 NO 3 . (встановіть вміст кожної пробірки, добравши необхідний реактив; запишіть хід досліду, спостереження, відповідні рівняння реакцій в молекулярній та іонній формах; у висновку укажіть номер пробірки та визначений розчин, відповідь обґрунтуйте.​

Answer 1

Determining the Substances in Two Numbered Test Tubes

To determine the substances in the two numbered test tubes, we need to perform a series of tests using appropriate reagents. Let's go through the steps for each test tube:

Test Tube 1:

1. Add a few drops of dilute sulfuric acid (H2SO4) to the test tube containing the solution. 2. Observe any changes in the solution.

Test Tube 2:

1. Add a few drops of dilute hydrochloric acid (HCl) to the test tube containing the solution. 2. Observe any changes in the solution.

Now, let's analyze the observations and determine the contents of each test tube.

Observations and Analysis:

Test Tube 1: - If the solution in Test Tube 1 turns milky or forms a white precipitate upon the addition of dilute sulfuric acid, it indicates the presence of a sulfate ion (SO4^2-). This suggests that the solution in Test Tube 1 contains a barium compound, as barium sulfate (BaSO4) is insoluble in water. - The reaction can be represented as follows: ``` Ba(NO3)2 + H2SO4 -> BaSO4 + 2HNO3 ```

Test Tube 2: - If the solution in Test Tube 2 produces a gas (effervescence) upon the addition of dilute hydrochloric acid, it indicates the presence of a carbonate ion (CO3^2-) or a bicarbonate ion (HCO3^-). This suggests that the solution in Test Tube 2 contains an ammonium compound, as ammonium carbonate (NH4)2CO3 or ammonium bicarbonate NH4HCO3 can release carbon dioxide (CO2) gas upon reaction with acid. - The reaction can be represented as follows: ``` NH4NO3 + HCl -> NH4Cl + H2O + CO2 ```

Conclusion:

Based on the observations and reactions, we can conclude the following:

- Test Tube 1 contains a solution of barium nitrate (Ba(NO3)2). - Test Tube 2 contains a solution of ammonium nitrate (NH4NO3).

The presence of barium sulfate (BaSO4) in Test Tube 1 and the release of carbon dioxide (CO2) gas in Test Tube 2 upon the addition of the respective acids confirm the presence of barium nitrate and ammonium nitrate in the two test tubes, respectively.

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