Acids (T4) Flashcards
What is the pH of acids?
Less than 7
How does the strength of an acid affect the pH?
The stronger the acid, the lower the pH number
What colour does acid turn blue litmus paper?
Red
What do acids do to universal indicator?
They turn universal indicator red if they are strong, and orange or yellow if they are weak
What element needs to be present for a substance to be acidic and why?
- hydrogen (generally lots of it)
- this is because acidity requires aqueous substances with a large amount of hydrogen ions (H+)
Remember!! Hydrogen only has one electron. Acids are always sources of hydrogen ions.
Acids are always sources of ……… ………
Acids are always sources of hydrogen ions
Describe dilute acids and concentrated acids…
- dilute acids:
Hydrochloric acid, sulphuric acid, nitric acid.
Theirs bottles are labelled with the label ‘irritant’.
If come into contact with skin can cause redness, blisters and a burning sensation. - concentrated acids:
Very corrosive.
Can attack metals and destroy skin.
List five acids you will find at home…
- ethanoic acid (vinegar)
- carbonic acid (fizzy drinks)
- tannic acid (tea)
- absorbic acid (vitamin c)
- citric acid (lemons)
Acids react with most metals and a salt is produced, but unlike the reaction between acids and bases we don’t get any water. What do we get instead?
Hydrogen gas
What is the general word equation for an acid reacting with metal?
Metal + acid > salt + hydrogen
The salt produced by reacting a metal with acid depends upon the reactants. Show the word equations of zinc + sulphuric acid and magnesium + hydrochloric acid…
Zinc + sulphuric acid > zinc sulphate + hydrogen
Magnesium + hydrochloric acid > magnesium chloride + hydrogen
What is the general word equation for acids reacting with metals?
Acid + metal > salt + hydrogen
What is the word and chemical equation for copper reacting with hydrochloric acid?
Copper + hydrochloric acid > copper chloride + hydrogen
Cu(s) + 2HCl(aq) > CuCl2(aq) + H2(g)
