Topic 4: Chemical Changes Flashcards
What is the difference between the strength of an acid and the concentration of an acid?
Strength of an acid - how much acid dissociates
Concentration- how much acid there is in a certain volume
Acid + metal oxide -> ?????
Salt + water
Acid + metal hydroxide -> ??????
Salt + water
Acid + metal carbonate -> ??????
Salt + carbon dioxide + water
Are metal oxides and hydroxides acids or alkalis?
Alkalis
What is an acid?
A substance that forms aqueous solutions with a pH of less than 7.
They form H+ ions in water
What is a base?
A substance with a oH greater than 7
What is an alkali?
A base that dissolves in water to form a solution with a pH greater than 7
Form OH- ions in water
Neutralisation equation
H+ + OH- -> H2O
What are strong acids?
Acids which ionise completely in water.
All acid particles dissociate to release H+ ions
What is a weak acid?
Acids that do not fully ionise in solution
Only a small proportion of acid particles dissociate to release H+ ions
What type of reaction is the ionisation of a weak acid?
A reversible reaction
What is pH a measure of?
The concentration of H+ ions in the solution
If a strong and weak acid have the same concentration, which will have a higher pH?
The weaker acid
How does potassium react with water?
Fizz + melts + burns