Question

В трех склянках без этикеток находятся растворы K2SO4? K2S, KNO3.Как химическим путем распознать ,какое вещество находится в каждой из склянок? Напишите уравнения реакций.

Answer 1

1-добавим BaCl2 в  осадок выпадет Ba(SO4)2
2 Ar2SO4 ,в осадок ArS
3 -методом исключения,в это склянке реакция не пойдет,т.к. ничего в осадок не выйдет.

Answer 2

Identifying Unknown Solutions in the Glassware

To identify the unknown substances in the three glassware solutions, we can use chemical reactions to determine which substances are present. We'll perform specific reactions with each solution to identify the compounds.

1. K2SO4 Solution: To identify the presence of K2SO4, we can add BaCl2 solution to the unknown solution. If a white precipitate forms, it indicates the presence of sulfate ions (SO4^2-), confirming the presence of K2SO4.

The chemical reaction can be represented as: ``` BaCl2 + K2SO4 → BaSO4 ↓ + 2KCl ```

2. K2S Solution: To identify the presence of K2S, we can add lead(II) acetate solution to the unknown solution. If a black precipitate forms, it indicates the presence of sulfide ions (S^2-), confirming the presence of K2S.

The chemical reaction can be represented as: ``` Pb(CH3COO)2 + K2S → PbS ↓ + 2KCH3COO ```

3. KNO3 Solution: To identify the presence of KNO3, we can perform a simple thermal decomposition reaction. When KNO3 is heated, it decomposes to produce potassium nitrite (KNO2) and oxygen gas (O2).

The chemical reaction can be represented as: ``` 2KNO3 (s) → 2KNO2 (s) + O2 (g) ```

By performing these specific chemical reactions, we can identify the substances present in each of the three solutions based on the observed reactions and precipitates formed.

I hope this helps! If you have further questions or need additional assistance, feel free to ask.