Question 1
What is the result of the limewater test used to identify carbon dioxide gas?
The right answer is the one marked above.
The limewater turns milky. The Ca(OH)2 in it reacts with the CO2 to form white CaCO3, which stays suspended in the water.
The "pop" belongs to hydrogen, the relighting splint to oxygen, and litmus turning blue reports that an alkali has formed.