Chapter 11 Qualitative Analysis Anions

Drag and drop the tests into the boxes to complete the table below.

(Match the empty boxes in the image with the options below by selecting the empty box and the correct option.)​ ​ ​​

• Add dilute nitric acid, then add aqueous barium nitrate.

• Carbonate CO₃^2-

• Add dilute nitric acid, then add aqueous silver nitrate.

• Chloride Cl^-

• Add dilute nitric acid, then bubble the gas evolved into limewater

• Nitrate NO₃^-

• Add aqueous sodium hydroxide, then add some aluminum powder. Warm

• Sulfate SO₄^2-

Drag and drop the observation into the boxes to complete the table below.

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• A gas evolves, which turn damp red litmus paper blue.

• Nitrate NO₃^-

• A gas evolves, which forms a white precipitate when bubbled through limewater.

• Sulfate SO₄^2-

• A white precipitate forms.

• Iodide I^-

• A yellow precipitate forms.

• Carbonate CO₃^2-

Drag and drop the observation into the boxes to complete the table below.

(Match the empty boxes in the image with the options below by selecting the empty box and the correct option.)​ ​ ​​

• Carbonate CO₃^2-

• 
• Nitrate NO₃^-

• 
• Sulfate SO₄^2-

• 
• Iodide I^-

• 

How much anion solution do you require for each anion test?

• enough to fill half the test tube

• enough to fill the entire test tube

• only about 2 cm³

Answer explanation

Similar to the cation tests, you should add enough anion solution to cover about 2 cm height from the base of the test tube (no need to use ruler, estimation is enough).

[NItrate test] Which of the following should be performed on the nitrate solution in the correct order?

1. ​​ (a)  

2. ​​ (b)  

3. ​ (c)   ​ ​ ​

• add aqueous sodium hydroxide
• add one piece of Al foil
• warm mixture

[Carbonate/Sulfate/Chloride/Iodide test] What acid should be added to the anion solution?

• hydrochloric acid

• nitric acid

• sulfuric acid

[Carbonate/Sulfate/Chloride/Iodide test] How much acid should be added to the anion solution?

• 1 drop only

• same volume as the anion solution

Answer explanation

Sufficient acid must be added to ensure that any possible carbonate ion impurities can react and be removed by the acid.