P1 - Chemical Changes Flashcards
What kind of ions do acids and alkalis form in water?
Acids - H+ ions
Alkalis - OH- ions
What is the reaction between an acid and a base called and what does it produce?
Neutralisation - produces salt + water
What is the difference between strong and weak acids?
Strong acids completely ionise in water whereas weak acids do not, so weak acids have reversible reactions.
What is pH a measure of?
The concentration of H+ ions in a solution
What are the two neutralisation reactions?
An acid + metal oxide OR an acid + metal hydroxide Both give salt + water Metal oxide and metal hydroxide are both bases
What do acids and metal carbonates produce?
Salt + Water + Carbon dioxide
How can you make soluble salts using an insoluble base?
- Warm dilute acid over Bunsen
- Add insoluble base a bit at a time until no more reacts
- Filter Out excess solid to get salt solution
What is the order of the reactivity series?
Potassium Sodium Lithium Calcium Magnesium (Carbon) Zinc Iron (Hydrogen) Copper
What does a Metal + water produce?
Metal Hydroxide + Hydrogen
Define oxidation
A gain of oxygen, so when you react a metal with oxygen it forms a metal oxide. It is also a loss of electrons.
Define reduction
Loss of oxygen. This is how you separate a metal from its oxide. It is also a gain of electrons.
What is reduction using carbon?
Some metals can be extracted from their ores chemically by reduction using carbon. In the reaction, the ore is reduced as oxygen is removed from it, and carbon gains the oxygen and is oxidised.
Define redox reaction
When electrons are transferred during oxidation and reduction. Remember using OIL RIG:
Oxidation Is Loss (of electrons)
Reduction Is Gain (of electrons)
Displacement reactions are redox reactions (metal ion is reduced and metal atom is oxidised)
