3rd Form Flashcards
What is filtration?
Filtration is using filter paper to separate a solid from a liquid. The substance left in the paper is called the residue, and the liquid that comes through is called the filtrate
What is crystallisation?
Crystallisation is used to separate a solute from a solution. It can be sped up by adding a thermal source underneath (eg a bunsen burner)
What is distillation?
Distillation is used to separate the components of a solution. We can use distillation to collect the water we would lose during crytillisation with a condenser
What is the test for water?
Anhydrous copper(II) sulphate: turns from white to blue
Properties of metals:
High mp/bp
Malleable
Electrical conductors
Diatomic elements
How do you illustrate diffusion of gases?
Ammonium chloride tube: Ammonium on one side, hydrogen chloride on another, when they bond they form a white ring of gas
Define an isotope
isotopes are atoms with the same number of protons but different numbers of neutrons.
What is oxidisation
The loss of electrons
What is reduction
The gain of electrons
What is the structure of an ionic compound?
Giant ionic lattice
Define ionic bonding
ionic bondingis the electrostatic attraction between oppositely charged ions.
Why do ionic compounds have high melting points?
Ionic bonds are very strong (1 mark)
In a giant ionic lattice there a lots of ionic bonds ( 1 mark)
So lots of energy is needed to break those bonds ( 1 mark)
Why can ionic solids not conduct electricity
- Electrical conductivity requires particles that can move freely
- In an ionic solid there are no free particles, so the ions can’t move freely
(vice versa for liquid)
Methyl Orange indicator colours
Acid: Red
Neutral: Yellow
Alkaline: Yellow
Phenolphthalien indicator colours
Acid: Colourless
Neutral: Colourless
Alkaline: Pink
Red litmus indicator colour
Acid: Red
Neutral: Red
Alkaline: Blue
Blue litmus indicator colours
Acid: Red
Neutral: Blue
Alkaline: Blue
Universal indicator colour:
Acid: Red/ Orange/Yellow depending on strengh
Neutral: Green
Alkaline: Light Blue/ Dark Blue/ Purple depending on strengh
Name the 4 main gases in the atmosphere and their approximate percentage in the air
Nitrogen: 78
Oxygen: 21
Argon: 0.96
Carbon dioxide: 0.04
Test for oxygen
Glowing splint relights
What ph solutions do metal oxides form? What ph solutiona do non-metal oxides form?
Metal oxides form alkaline solutions
Non-metal dioxides form acidic solutions
Define an acid, base, and alkali
Acid: H+ donor
Base: H+ acceptor
Alkali: OH- donor
Acid+Base to ?+?
Acid+Base to Salt and Water
Reactions: Base disappears
Acid+Carbonate to ?+?+?
Acid + Carbonate→Salt + Water+ Carbon dioxide
Reactions: Carbonate disappears
Effervesence
Test for carbon dioxide?
Bubble through limewater- if co2 is present, the limewater turns cloudy
What are the two main components of a metallic structure
1.A lattice of positive metal ions.
2.A sea of delocalizedelectrons.
Define metallic bonding:
Metallic bonding is the electrostatic attraction between the positive metalions and the negative delocalized electrons.
Why do metals have high melting points?
Because the metallic bonding is usually very strong……so lots of energy is needed to break it.
Why can metals conduct electricity?
Because the delocalized electrons are free to move through the lattice.
Why are metals malleable
Because the layers of metal ions can slide over each other.
Metal Carbonate to ?+? (reaction occurs with application of heat energy)
Metal carbonate →Metal oxide + Carbon dioxide
Reactions: Colour Change? idk
Metal+Water to ?+?
Metal + Water →Metal hydroxide + Hydrogen
Effervesence
Solid Disappears
Metal+Steam to ?+?
Metal + Steam→Metal oxide+ Hydrogen
Acid+Metal to ?+?
Acid + Metal →Salt + Hydrogen
Metal disappears
Fizzing/ effervesence
Reactivity series from highest reactivity to lowest:
K
Na
Li
Ca
Mg
Al
C
Zn
Fe
Pb
H
Cu
Ag
Au
Test for hydrogen
Lit spint- squeaky pop
Observations of a displacments reaction
Solid colour change (Or/and) Solution colour change
Describe the two ways to extract Ores
- Electricity
Ores are broken apart with electricity and the elements are extracted individually. - Carbon
Metals/Ores less reactive than carbon are displaced by it. They are then extracted as sole elements.
What is reduction and oxidisation in terms of oxygen
Reduction: The loss of oxygen
Oxidisation: The gain of oxygen
(Reduction and oxidisation have 2 different meanings, in terms of electrons it is the other way around eg reductions gains electrons and oxidisations loses electrons).
What is a redox reduction
Redox = reduction and oxidation in the same reaction
What is the chemical name for rust
hydrated iron(III)oxide
What is the barrier method and how does it work?
Coating iron with a layer of lastic, oil or paint to stop it coming into contact with oxygen and water.
What is sacrifical protection and how does it work?
Placing a block of a more reactive metal near the Iron to displace the Iron from the rust as soon as it forms
