gas tests

Question 1

how to test for oxygen gas

Answer 1

glowing splint test

Question 2

explanation of the glowing splint test

Answer 2

oxygen is needed for combustion (burning carbon from the wooden splint). if oxygen is present in the test tube, a glowing splint re-ignites when it is held inside that tube and exposed to a high concentration of oxygen

Question 3

instructions for the glowing splint test

Answer 3

Put a small amount of manganese dioxide powder into a test tube and add hydrogen peroxide liquid. These chemicals will react together to create oxygen gas. Hold your thumb over the test tube to collect the gas inside the test tube. Remove the thumb quickly and place a glowing splint into the test tube. If the splint reignites then it is likely the gas produced was oxygen

Question 4

see glowing splint

Answer 4

The solution turned black and bubbled over the top of the test tube
The glowing splint was relit meaning that there was oxygen being created

Question 5

how to rest for hydrogen gas

Answer 5

pop-test

Question 6

instructions for the pop-test

Answer 6

Put a small piece of magnesium ribbon into a test tube with a small amount of hydrochloric acid. These chemicals will react together to create hydrogen gas. Hold your thumb over the test tube to collect the gas inside the test tube. Remove the sun quickly and place a lit splint into the test tube. If the gas makes a high, loud pop, then it is likely the gas produced is hydrogen.

Question 7

explanation for the pop-test

Answer 7

Hydrogen ignites in the air. So if hydrogen is present in the test tube, a lit splint held near the mouth of the test tube with ignite with a squeaky pop

Question 8

see pop test

Answer 8

• The magnesium turned white
• The solution separated and was clear down the bottom, and milky at the top
• The magnesium floated at the top of the hydrochloric acid
• Lots of bubbles
  Loud pop sound

Question 9

how to test for carbon dioxide

Answer 9

lit splint or limewater test

Question 10

lit splint test intructions

Answer 10

Put a small amount of calcium carbonate with hydrochloric acid in a test tube. These chemicals will react together to create carbon dioxide gas. Hold your thumb over the test tube to collect the gas inside the test tube. Remove the thumb quickly and place a lit splint into the test tube. If bullet splint is extinguished then it is likely the gas produced is carbon dioxide

Question 11

lit splint explanation

Answer 11

Carbon dioxide displaces oxygen from the test tube. If there is no oxygen, a flame cannot keep burning, so the flame will be extinguished

Question 12

limewater test instructions

Answer 12

Put a small amount of calcium carbonate with hydrochloric acid in a boiling tube. These chemicals will react together to create carbon dioxide gas. Place a bung with a delivery test tube over the boiling tube. Place the free end of the delivery tube into a test tube filled with clear limewater. Observe the gas bubbling into the lime water. If the lime water turns cloudy then it is likely that the gas produced is carbon dioxide

Question 13

limewater test explanation

Answer 13

Carbon dioxide is a colourless gas and lime water is a solution of calcium hydroxide in water, which is also colourless. The carbon dioxide gas reacts with the lime water and changes it into calcium carbonate, which is not soluble (cannot dissolve) in water and appears a Milky white colour