Tests For Gases And Metals

Question 1

What does the result of a fade test let you determine

Answer 1

Which gas or ion is present

Question 2

What is the test for hydrogen and why do we get This result

Answer 2

If hydrogen is present in a test tube a lighted splint held near its mouth ignites with a squeaky pop as hydrogen ignites in air

Question 3

What is the test for oxygen and why do we get this result

Answer 3

If it is present in a test tube a glowing splint relights when held inside as oxygen supports combustion

Question 4

What is the test for carbon dioxide and why is this the result

Answer 4

(Limewater is a solution of calcium hydroxide) if carbon dioxide is bubbles through limewater the limewater turns milky or cloudy white. This is because carbon dioxide reacts with calcium hydroxide to produce a white precipitate or calcium carbonate

Question 5

What is the test for chlorine and why do we get this result

Answer 5

Damp litmus paper is bleached white when placed in chlorine (if damp blue litmus paper is used the paper turns red then white). This is since chlorine is an acidic gas that also acts as a bleach

Question 6

Test for copper ions in a solution of copper sulfate

Answer 6

Add sodium hydroxide solution. You get a blue precipitate