chem hw Flashcards
Explain why potassium bromide can react with chlorine.
Chlorine is more reactive than bromine, so can displace it form potassium bromide.
Give two uses of graphene.
Electronics and composites
Name the process used to extract metals more reactive than carbon.
Electrolysis
When preparing a soluble salt in the laboratory, explain why dilute acid is used.
It is generally safer.
Explain why graphite is often used for the electrodes.
It conducts electricity and is relatively unreactive.
State and explain whether this process is oxidation or reduction.
Al → Al³⁺ + 3e⁻
Oxidation, as aluminium has lost electrons.
In this reaction, what has been oxidised and what has been reduced?
2Al + 3Ca²⁺ → 2Al³⁺ + 3Ca
Al has been oxidised.
Ca²⁺ has been reduced.
Describe the trend in the reactivity of the alkali metals.
Increases down the group.
Describe the structure of graphite.
Each carbon atom forms three covalent bonds with three other carbon atoms.
The atoms form layers made of hexagonal rings.
Define mixture.
Two or more elements or compounds together, but not chemically combined.
State and explain whether this process is oxidation or reduction.
F₂ + 2e⁻ → 2F⁻
Reduction, as fluorine has gained electrons.
Define inert.
unreactive
Explain why sodium is less reactive than potassium.
It has fewer shells/electrons.
It has a stronger attraction from the nucleus to the outer shell.
It is harder to lose the outer shell electron.
Explain why atoms have an overall neutral charge.
Protons are positive and electrons are negative.
Atoms have equal numbers of protons and electrons.
So the charges sum to zero.
Explain why diamond has a high melting and boiling point.
It has a giant covalent structure.
It has strong covalent bonds between atoms.
Which require a lot of energy to overcome.
