C1.3 Acids Flashcards
Why does the stomach produce hydrochloric acid?
- to help digestion
- to kill bacteria
What causes indigestion?
Excessive stomach acid
What type of medicines treat indigestion?
Antacids
What is a base dissolved in water?
An alkali
How do antacids treat indigestion?
By neutralising excess stomach acid
What types of bases neutralise acid?
- metal oxides
- metal hydroxides
- metal carbonates
What pH does a neutral liquid have?
pH 7
What is a substance with a pH of 0?
An acid
What is a substance with a pH of 14?
An alkali
What colour does damp blue litmus paper turn under acidic conditions?
Red
What colour does damp red litmus paper turn under alkaline conditions?
Blue
How can you find out if a substance is an acid or an alkali?
By using an indicator
What does an acid + a metal hydroxide produce?
A salt + water
What does an acid + a metal carbonate produce?
A salt + water + carbon dioxide
What does an acid + a metal oxide produce?
A salt + water
What is electrolysis?
The process of decomposing compounds using a d.c. current
What is the test for chlorine gas?
Seeing if it bleaches damp blue litmus paper red and then white
What is the test for hydrogen gas?
Seeing if a lighted splint explodes with a squeaky pop
What are the uses of chlorine?
- treatment of water supplies
- the manufacture of bleach and other cleaning products
- the manufacture of plastics like PVC
What are the hazards of producing chlorine on a large scale?
If there is a leak near a town many people could die
Why is chlorine hazardous?
It is a toxic gas
What does the electrolysis of sea water produce?
Hydrogen and chlorine gas
What does the electrolysis of water produce?
Hydrogen and oxygen gas
What is the test for oxygen?
Seeing if it relights a glowing splint
