chemistry topic 4 Flashcards
what is an ore
A metal compound within a rock is an ore.
what must happen for metals to be extracted from their oxides
To extract metals from their oxides, the metal oxides must be reduced (have oxygen removed).
what happens to metal atoms when the metal reacts with other substances
When metals react with other substances the metal atoms form positive ions.
what is the reactivity of metals linked to
its tendency to form positive ions
how must metals above carbons level of reactivity be extracted
by electrolysis.
how must metals below carbons level of reactivity be extracted
Metals below carbon can be extracted from their ores by reduction using carbon.
(reduction involves the loss of oxygen.)
what can a more reactive metal do to a less reactive metal
A more reactive metal can displace a less reactive metal
from its compound in displacement reactions.
what is oxidisation
Oxidation Is Loss of electrons
what is reduction
Reduction Is Gain of electrons
what is the equation for when a metal reacts with an acid
Metal + acid -> salt + hydrogen
complete the equation Magnesium + hydrochloric acid
Magnesium + hydrochloric acid –> magnesium chloride + hydrogen
what is the name of the salt formed when a metal reacts with Hydrochloric acid
Chloride
what is the name of the salt formed when a metal reacts with Sulfuric acid
Sulfate
what is the name of the salt formed when a metal reacts with Nitric acid
Nitrate
what happens in a reaction between magnesium and hydrochloric acid
the hydrogen ions
are displaced from the solution by magnesium as the magnesium is more reactive than hydrogen.
what are ions that dont change a reaction known as
spectator ions.
what is the equation for Making Soluble Salts from acids and alkalis
Acid + Alkali (or base) → Salt + Water
what is the equation for Making Soluble Salts from acids and metal carbonates
Acid + Metal carbonate → Salt + Water + Carbon dioxide
describe the practical for making crystals
- Add acid to a beaker
- Warm acid using bunsen burner
- Add [metal] oxide
- Stir
- Continue adding until [metal] oxide is in excess - you will see
undissolved powder at the bottom of the beaker (this ensure that all the acid
has fully reacted) - Filter using a filter paper and funnel - to remove excess [metal] oxide
- Heat solution in an evaporating basin - removes
excess water - Leave to crystallise
what do Acids contain
hydrogen ions (H+)
what do Alkalis contain
hydroxide ions (OH–)
describe the titration practical
- Measure volume of acid using
measuring cylinder - Pour acid in conical flask
- Add indicator to flask
- Sodium hydroxide in burette
- White tile under flask - makes it easier to see colour change
- Add sodium hydroxide slowly and swirl flask
- Colour change - pink to colourless for phenolphthalein indicator
- Check volume of sodium hydroxide added
what must happen to acids when they are mixed with water for them to be acidic
Acids must dissolve in water to be acidic
what is a concentrated acid
A concentrated acid has a small amount of solute dissolved in the solvent.
what is a dilute acid
A dilute acid has a larger amount of solute dissolved in the solvent
what happens when an ionic compound is melted or dissolved in water
the ions are free to move about the liquid or solution.
what happens to positive ions during electrolysis
Positive ions (cations) go to negative electrode (cathode) and are reduced
what happens to negative ions during electrolysis
Negative ions (anions) go to the
positive electrode (anode) and are oxidised.
describe the electrolysis required practical
- Pour ionic solution into beaker [sodium chloride]
- Put 2 graphite electrodes into beaker - graphite is unreactive
- Switch on power supply
- Bubbles of chlorine gas produced at the anode
- Bubbles of hydrogen gas produced at cathode
- Sodium hydroxide left in beaker
