Question

помогите плиз.в трех склянках без этикеток находятся белые кристаллические вещества:нитрат натрия, нитрат аммония и сульфат аммония.как распознать каждое из веществ?составьте план распознавания и запишите уравнения реакций.

Answer 1

Для начала прильем в каждую пробирку некоторое количество воды,то есть растворим вещества.Затем добавим в каждую гидроксид бария(II):

 

$2NaNO_3+ Ba(OH)_2 =2 NaOH+Ba(NO_3)_2$- нет видимых изменений

 

$(NH_4)_2SO_4+Ba(OH)_2=BaSO_4+2NH_3+2H_2O$- выпадает белый осадок сульфат бария(II)

 

$2NH_4NO_3+Ba(OH)_2=Ba(NO_3)_2+NH_3+2H_2O$ - выделение газа с резким запахом - аммиака

Answer 2

Plan for Identifying the Substances

To identify the substances in the three unlabeled containers, we can use a combination of chemical tests and reactions specific to each compound. Here is a plan for identifying each substance:

1. Sodium Nitrate (NaNO3): - Test for solubility: Sodium nitrate is highly soluble in water. Add a small amount of the substance to a test tube with water and observe if it dissolves completely. - Confirmatory test: Add a few drops of silver nitrate solution (AgNO3) to a small amount of the dissolved substance. A white precipitate of silver chloride (AgCl) should form, confirming the presence of sodium nitrate. - Equation for the confirmatory test: NaNO3(aq) + AgNO3(aq) → AgCl(s) + NaNO3(aq)

2. Ammonium Nitrate (NH4NO3): - Test for solubility: Ammonium nitrate is also highly soluble in water. Add a small amount of the substance to a test tube with water and observe if it dissolves completely. - Confirmatory test: Add a few drops of sodium hydroxide solution (NaOH) to a small amount of the dissolved substance. If ammonium nitrate is present, it will produce ammonia gas (NH3), which can be detected by its characteristic smell. - Equation for the confirmatory test: NH4NO3(aq) + NaOH(aq) → NH3(g) + H2O(l) + NaNO3(aq)

3. Ammonium Sulfate (NH4)2SO4: - Test for solubility: Ammonium sulfate is soluble in water, but it is less soluble than the previous two compounds. Add a small amount of the substance to a test tube with water and observe if it dissolves partially or not at all. - Confirmatory test: Add a few drops of barium chloride solution (BaCl2) to a small amount of the dissolved substance. A white precipitate of barium sulfate (BaSO4) should form, confirming the presence of ammonium sulfate. - Equation for the confirmatory test: (NH4)2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NH4Cl(aq)

Summary of Identification Tests and Equations

1. Sodium Nitrate (NaNO3): - Test for solubility: Highly soluble in water. - Confirmatory test: AgNO3(aq) + NaNO3(aq) → AgCl(s) + NaNO3(aq).

2. Ammonium Nitrate (NH4NO3): - Test for solubility: Highly soluble in water. - Confirmatory test: NH4NO3(aq) + NaOH(aq) → NH3(g) + H2O(l) + NaNO3(aq).

3. Ammonium Sulfate ((NH4)2SO4): - Test for solubility: Soluble in water, but less soluble than the previous two compounds. - Confirmatory test: (NH4)2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NH4Cl(aq).

Remember to perform these tests in a well-ventilated area and handle chemicals with caution.