Chemical Tests for Gases

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Which gas causes the limewater to turn milky or cloudy white?

Chlorine

Hydrogen

Oxygen

Carbon dioxide (correct)

What is the observation when a glowing splint is held inside a test tube with hydrogen?

Pop sound heard (correct)

Limewater turns milky or cloudy white

Paper turns white

Splint relights

What inference can be made when damp litmus paper turns white in a test tube?

Hydrogen is present

Oxygen is present

Chlorine is present (correct)

Carbon dioxide is present

What happens when a lighted splint is held inside a test tube containing oxygen?

Splint relights Signup and view all the answers

What causes the observation of a pop sound when a lighted splint is held near the mouth of a test tube containing hydrogen?

Presence of hydrogen Signup and view all the answers

What gas reacts with calcium hydroxide solution to produce a white precipitate of calcium carbonate?

Carbon dioxide Signup and view all the answers

What is the purpose of carrying out a flame test?

To produce a unique flame color to identify the presence of specific metal ions Signup and view all the answers

What happens when excess sodium hydroxide solution is added to a solution containing aluminium ions, calcium ions, and magnesium ions?

The calcium hydroxide precipitate dissolves to form a colorless solution Signup and view all the answers

How are ions of group 1 metals (Li+, Na+, and K+) identified?

By reacting with dilute sodium hydroxide solution to produce a unique flame color Signup and view all the answers

How are carbonate ions, CO32-, detected?

By reacting with dilute acid to release bubbles Signup and view all the answers

What happens when a few drops of dilute sodium hydroxide solution react with aluminium ions, calcium ions, and magnesium ions?

They all produce a white precipitate Signup and view all the answers

Why do ions of group 1 metals not form white precipitates with dilute sodium hydroxide solution?

Because they are soluble in water Signup and view all the answers

What is the effect of adding excess sodium hydroxide solution on the aluminium hydroxide precipitate?

It dissolves to form a colorless solution Signup and view all the answers

What is the main purpose of adding excess sodium hydroxide solution when testing for aluminium, calcium, and magnesium ions?

To dissolve the white precipitates formed initially Signup and view all the answers

What is the significance of observing and recording the flame color during a flame test?

To identify the presence of specific metal ions Signup and view all the answers

What is the purpose of testing for negatively charged carbonate ions?

To detect carbonate ions using a dilute acid Signup and view all the answers

Chemical Tests for Gases

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