Topic 3 - Acids Flashcards
What are 2 uses of chlorine?
- bleaches/disinfectants
- to make the polymer poly(chloroethene)
The electrolysis of water produces what gases at what electrodes?
Oxygen gas at the anode and hydrogen gas at the cathode
(in all the examples of electrolysis we need to know, hydrogen is always produced at the cathode and never the anode, i.e. hydrogen has positive ions so is always attracted to the negative electrode)
How do you test for hydrogen gas?
Hydrogen ignites/burns when mixed with air, so you will hear a squeaky pop noise.
What is a naturally occurring substance that produces chlorine gas when electrolysed?
Brine/sea water.
How do you test for chlorine gas?
Chlorine will bleach damp blue litmus paper white.
What are two reasons why the stomach uses hydrochloric acid?
- To break down ingested food into smaller molecules
- To kill bacteria present on any ingested food
What is the type of reaction that happens when you react an acid with a base?
A neutralisation reaction.
What is electrolysis?
Electrolysis is passing an electrical and direct current through a compound that is molten or in solution in order to decompose it
What happens when ions get to the electrodes during electrolysis?
- they lose their charge
- atoms of elements are formed
The electrolysis of hydrochloric acid produces what gases at which electrodes?
It produces chlorine at the anode and hydrogen at the cathode
How do you test for oxygen?
Oxygen will relight a glowing splint
When reacting a metal oxide with a base, what is formed?
A neutral salt and water
When reacting a metal carbonate with a base, what is formed?
A neutral salt, water and carbon dioxide
When reacting an alkaline hydroxide base with an acid, what is formed?
A neutral salt and water
how can excess acid in the stomach be neutralised?
by indigestion tablets; each tablet contains a base that will neutralise the acid in the stomach
