Topic 4 Chemical Changes Flashcards
What happens when metals react with water or acid?
Lose electrons and form positive ions
Which 2 non-metals are included in the reactivity series?
Hydrogen and carbon
What is the order of metals in the reactivity series?
Potassium
Sodium
Lithium
Calcium
Magnesium
Carbon
Zinc
Iron
Hydrogen
Copper
What is the order of the top 5 metals in the reactivity series?
Potassium
Sodium
Lithium
Calcium
Magnesium
What is the order of the bottom 5 metals (and nonmetals) in the reactivity series?
Carbon
Zinc
Iron
Hydrogen
Copper
How else can the pH be measured other than using universal indicator?
pH probe
What do acids produce in aqueous solutions?
Hydrogen ions
What are bases?
insoluble metal hydroxides and metal oxides
What are alkalis?
Soluble metal hydroxides
What do aqueous solutions of alkalis contain?
Hydroxide ions
What is the difference between an alkali and a base?
Alkalis are bases that dissolve in water to form alkaline solutions
What is the word equation for a neutralisation reaction?
Acid + base > salt + water
In neutralisation reactions between an acid and alkali what do hydrogen ions and hydroxide ions react to form?
Water
What are titrations used for?
find reacting volumes of acid and alkali solutions
What is pH a measure of?
Concentration of hydrogen ions in a solution
What happens to a strong acid in aqueous solution?
Ionised completely (all acid particles dissociate to release H+ ions)
What are 3 examples of strong acids?
Sulfuric
Hydrochloric
Nitric
What are 3 examples of weak acids?
Ethanoic
Citric
Carbonic
What happens to a weak acid in aqueous solution?
Partially ionised (small proportion of acid particles dissociate to release H+ ions)
What is the concentration of an acid a measure of?
How much acid there is in a certain volume of water
What is an acids strength a measure of?
What proportion of acid molecules ionise in water
What type of reaction is a metal reacting with oxygen to produce metal oxides?
Oxidation
How are most metals in the earth found?
As compounds
How are unreactive metals such as gold found in the earth?
As the metal itself
What is an ore?
rock that contains enough of metal or metal compound to make extracting metal worthwhile
How can metals less reactive than carbon be extracted from their oxides?
By reduction with carbon