4C chemical analysis Flashcards
obsevb sodium hydroxide test on copper ions
blue precipitate
What color flame is produced by lithium ions?
Crimson red
Which ion produces a yellow flame during a flame test?
Sodium ions
True or False: Barium ions produce a green flame.
True
Fill in the blank: The flame test is used to identify _______ in a sample.
metal ions
What color flame does potassium ions produce?
Lilac
What is the purpose of adding sodium hydroxide to a solution when testing for ions?
To precipitate metal hydroxides
Which metal ion produces a blue precipitate with sodium hydroxide?
Copper(II) ions
What is the color of the precipitate formed when iron(II) ions react with sodium hydroxide?
Green
True or False: Calcium ions produce a white precipitate with sodium hydroxide.
False
What color precipitate do aluminum ions form when sodium hydroxide is added?
White
Which ion is indicated by a red-brown precipitate with sodium hydroxide?
Iron(III) ions
When testing for ammonium ions, what is the expected result after adding sodium hydroxide and heating?
A pungent gas (ammonia) is released
True or False: Silver ions produce a yellow precipitate with sodium hydroxide.
False
What is the color of the precipitate formed when lead(II) ions react with sodium hydroxide?
White
Fill in the blank: The test for carbonate ions involves adding an acid to produce _______.
carbon dioxide
What color precipitate is formed when zinc ions react with sodium hydroxide?
White
Which ion produces a white precipitate that dissolves in excess sodium hydroxide?
Zinc ions
What gas is evolved when hydrochloric acid is added to carbonate ions?
Carbon dioxide
What is the appearance of a copper(II) hydroxide precipitate?
Blue
True or False: A flame test can be used to identify non-metal ions.
False
What color flame is produced by strontium ions?
Crimson red
What test can be used to confirm the presence of sulfate ions?
Adding barium chloride to form a white precipitate
Which ion produces a white precipitate with barium chloride?
Sulfate ions
Fill in the blank: The flame test is not effective for identifying _______ ions.
alkaline earth metal
What is the first step in conducting a flame test?
Clean the wire loop with hydrochloric acid
True or False: The color of the flame is specific to each metal ion.
True
What is the observation when dilute hydrochloric acid (HCl) is added to a solution containing carbonate ions?
Effervescence due to the release of carbon dioxide gas.
True or False: Barium chloride (BaCl2) can be used to test for sulfate ions.
True.
What color precipitate forms when barium chloride is added to a solution containing sulfate ions?
A white precipitate of barium sulfate (BaSO4) forms.
Fill in the blank: The test for chloride ions involves adding _________ to the solution.
Silver nitrate (AgNO3).
What is the observation when silver nitrate is added to a solution containing chloride ions?
A white precipitate of silver chloride (AgCl) forms.
What is the test for identifying the presence of ammonium ions?
Add sodium hydroxide (NaOH) and gently heat the solution; a pungent gas (ammonia) is released.
What color flame indicates the presence of lithium ions?
A crimson red flame.
Which ion produces a yellow flame during a flame test?
Sodium ions (Na+).
What is the observation when adding dilute HCl to a solution containing sulfite ions?
Effervescence due to the release of sulfur dioxide gas.
True or False: A blue solution indicates the presence of copper(II) ions.
True.
What precipitate is formed when sodium hydroxide is added to a solution containing iron(III) ions?
A reddish-brown precipitate of iron(III) hydroxide (Fe(OH)3) forms.
What is the observation when barium chloride is added to a solution containing carbonate ions?
No visible change; barium carbonate is insoluble.
Which test is used to confirm the presence of nitrate ions?
Brown ring test using iron(II) sulfate and concentrated sulfuric acid.
What gas is released when dilute HCl is added to a solution containing metal carbonates?
Carbon dioxide (CO2) gas.
What is the observation for a solution containing phosphate ions when treated with ammonium molybdate?
A yellow precipitate of ammonium phosphomolybdate forms.
What color is the precipitate formed when silver nitrate is added to a solution containing bromide ions?
A pale yellow precipitate of silver bromide (AgBr) forms.
Fill in the blank: The test for iron(II) ions involves adding _________ to the solution.
Potassium ferricyanide (K3[Fe(CN)6]).
What is the observation when potassium ferricyanide is added to a solution containing iron(II) ions?
A blue precipitate of Turnbull’s blue (ferrous ferricyanide) forms.
What happens when you add dilute HCl to a solution of lead(II) ions?
No visible reaction occurs.
True or False: The addition of ammonium hydroxide can confirm the presence of zinc ions.
True.
What color precipitate is formed when sodium hydroxide is added to a solution containing aluminum ions?
A white precipitate of aluminum hydroxide (Al(OH)3) forms.
What is the observation when a solution containing iodide ions is treated with chlorine water?
A brown color develops due to the formation of iodine.
What is the purpose of adding dilute nitric acid before the silver nitrate test for halides?
To remove any carbonate ions that could interfere with the test.
What is the test for detecting the presence of magnesium ions in solution?
Addition of sodium hydroxide, resulting in a white precipitate of magnesium hydroxide (Mg(OH)2).
What is the observation when a solution containing sulfide ions is treated with dilute HCl?
The release of hydrogen sulfide gas, which has a characteristic rotten egg smell.
What is the test for bicarbonate ions (HCO3-)?
Add dilute acid; effervescence indicates the presence of HCO3-.
What gas is produced when bicarbonate ions react with dilute acid?
Carbon dioxide (CO2) is produced.
True or False: Ammonium ions (NH4+) can be tested by adding sodium hydroxide and heating.
True.
What is the observable result when ammonium ions are present after heating with sodium hydroxide?
The production of ammonia gas, which has a characteristic pungent smell.
Fill in the blank: The test for sulfate ions (SO4 2-) involves adding _______ to a solution.
Barium chloride.
What is the visible result of a positive test for sulfate ions?
A white precipitate of barium sulfate (BaSO4) forms.
Which ion can be detected by the formation of a white precipitate when treated with barium chloride?
Sulfate ions (SO4 2-).
What is the chemical reaction occurring when bicarbonate ions react with an acid?
HCO3- + H+ → CO2 + H2O.
True or False: Ammonium ions do not produce a smell when heated with sodium hydroxide.
False.
What color is the precipitate formed when barium sulfate is produced?
White.
What indicates the presence of ammonium ions in a solution?
The smell of ammonia gas after heating with sodium hydroxide.
When testing for sulfate ions, what is the role of barium chloride?
It reacts with sulfate ions to form a white precipitate.
Fill in the blank: The test for bicarbonate involves observing ________.
Effervescence.
What does the effervescence in the bicarbonate test indicate?
The release of carbon dioxide gas.
Which reagent is used to test for ammonium ions?
Sodium hydroxide (NaOH).
Describe the procedure to test for sulfate ions.
Add barium chloride to the solution and look for a white precipitate.
True or False: The presence of HCO3- can be confirmed by the formation of a gas upon reaction with an acid.
True.
What is the chemical formula for ammonium ions?
NH4+.
What is formed when barium sulfate precipitates?
A solid that can be filtered out from the solution.
What is the significance of the smell of ammonia in the ammonium test?
It confirms the presence of ammonium ions.
What is the first step in testing for sulfate ions?
Add barium chloride to the solution.
True or False: The presence of sulfate ions can be confirmed without any visible change.
False.
What happens to the solution when bicarbonate ions are present?
It produces bubbles due to the release of carbon dioxide.
What is the result of adding barium chloride to a solution containing sulfate ions?
A white precipitate of barium sulfate forms.
What is the test for the presence of bicarbonate ions?
Add a dilute acid and observe for effervescence.
