CGP Flashcards
Where is the zig zag line separating metals from non metals?
Boron to Astatine
Definition of ionic bonding?
- the electrostatic attraction between two oppositely charged ions
- between metal (+ve ion) and non metal (-ve ion)
What does OILRIG mean
Oxidation Is Loss, Reduction Is Gain
What is an anion?
-ve ion
What is a cation?
+ve ion
Properties of ionic compounds?
- high MP/BP as there are strong ionic bonds
- higher charge ions have higher MP and BP
- usually soluble in water but not in organic solvents
- can only conduct electricity when in molten form or dissolved
How do you draw an ionic compound structure?
•giant ionic lattice
Definition of covalent bonding?
- the strong electrostatic attraction between two nuclei and a shared pair of electrons
- between two non metals
Properties of simple molecular covalent compounds
- low MP/BP because of weak inter molecular forces
- poor conductivity because no molecules are charged
- poor solubility in water (except HCl and NH3)
- good solubility in organic solvents
Structure of diamond
•each carbon atom forms four string covalent bonds making a giant molecule
Properties of diamond
- high MP/BP (sublimes) because structure has lots of strong covalent bonds
- not soluble
- can’t conduct electricity
- hard and used for cutting
Structure of graphite
•each carbon is joined to three others to form hexagonal layer, they can slide
Properties of graphite
- high MP/BP
- not soluble
- can conduct electricity, as it has free electrons
- used for electrodes, lubricants, pencils
Definition of metallic bonding
•the attraction between two positive metal jobs and delocalised electrons
Structure of metallic compounds
- giant lattice of positive metal ions
* sea of delocalised electrons
Properties of metallic compounds?
- high MP/BP because metallic bonding is very strong
- not soluble
- good conductor as electrons are free to move
- malleable as layers of metal can slide over each other without disrupting the metallic bonding
Definition of isotope
Atoms with the same number of protons but a different number of neutrons
How do you calculate percentage yield
% yield = actual yield over theoretical yield x100
What does moles equal
Mass over RAM
What is the molar mass
- The RAM of an atom in grams
* e.g. carbon has 12g
What is Avogadro’s number?
6.023x10^23
How much volume does one mole of gas occupy?
24 dm cubed
What equation links moles of gas and volume?
Volume (dm cubed) = moles of gas x 24
Equation linking moles, concentration and volume
Moles= concentration x volume
Equation linking concentration, mass and volume
Concentration = mass over volume
What is the liquid in electrolysis called?
Electrolyte
What are electrolytes made of?
Melted or dissolved ionic compounds
How does the electrolyte conduct electricity?
It has free ions
How do electrons flow during electrolysis?
- electrons are taken away from ions st the positive electrode (anode)
- they are given to other ions st the negative electrode (cathode)
How can you find out if a substance is an electrolyte?
- place a conductivity probs in it
* if a current flows through the circuit then it’s an electrolyte
What happens at the cathode in the electrolysis of lead bromide?
- positive lead ions are attracted to the negative cathode
- at the cathode they accept two electrons to become a lead atom
- the lead that forms sinks to the bottom
- Pb^2 + 2e to Pb
What happens at the anode in the electrolysis of lead bromide?
- the negative bromine ions are attracted to the positive anode
- at the anode two bromide ions loss one electron each and become s bromine molecule
- Brown bromine gas forms st the top of the anode
- 2Br to Br2 +2e
Why will hydrogen gas be produced in the electrolysis of aqueous solutions?
- if both hydrogen ions and metal ions are present at the cathode
- If the metal ions are more reactive than hydrogen ions
When will a solid layer of pure metal be produced in electrolysis of aqueous solutions?
- if both hydrogen ions and metal ions are present at the cathode
- If the metal ions are less reactive than hydrogen ions
What forms at the anode in the electrolysis of aqueous solutions?
- if halide ions are present then they form
* if no halide ions are present then oxygen is formed
What are the three examples of the electrolysis of aqueous solutions?
- sulfuric acid
- sodium chloride
- copper (II) sulfate
What ions does sulfuric acid (H2SO4) contain
- SO4^2-
- H+
- OH-
What happens at the anode in the electrolysis of sulfuric acid?
- hydroxide ions lose electrons more easily than sulfate ions
- at the anode oxygen and water are produced
- 4OH- to O2 + 2H2O + 4e-
What happens at the cathode in the electrolysis of sulfuric acid?
- hydrogen ions accept electrons
- hydrogen gas is produced at the cathode
- 2H+ + 2e- to H2
What are the ions contained in sodium chloride NaCl?
- Na+
- Cl-
- OH-
- H+
What happens at the cathode in the electrolysis of sodium chloride?
- hydrogen ions accept electrons more easily than sodium ions
- at the cathode hydrogen gas is produced
- 2H+ + 2e- to H2
What happens at the anode in the electrolysis of sodium chloride?
- chloride ions lose electrons more easily than sodium ions
- at the anode chloride gas is produced
- 2Cl- to Cl2 + 2e-
What are the ions in copper sulfate
- Cu2+
- SO4^2-
- H+
- OH-
What happens at the cathode in the electrolysis of copper (II) sulfate?
- copper ions accept electrons more easily than hydrogen ions
- at the cathode a copper metal is produced
- Cu2+ + 2e- to Cu
What happens at the anode in the electrolysis of copper sulfate?
- hydroxide ions lose electrons more easily than sulfate ions
- at anode oxygen and water are produced
- 4OH- to O2 + 2H2O + 4e-
How can amount of product in electrolysis change?
Increase the number of electrons to increase the substance produced
How can more electrons be added to electrolysis?
- do it for a longer time
* increase the current
How many coulombs is one faraday?
96,000
What is a faraday
One faraday contains one mole of electrons
What are group 1 known as?
The alkali metals
What happens when a group one metal reacts with water?
•sodium + water to sodium hydroxide + hydrogen
What observations are seen when lithium, sodium and potassium react with water?
- lithium- moves slowly, fizzes then disappears, produces alkaline
- sodium- moves quickly, fizzes rapidly, may ignite, then disappears, produces alkaline
- potassium- lilac flame, sometimes explodes, then disappears, produces alkaline
What happens when iodine is displaced by chlorine or bromine in potassium iodide?
•Brown solution forms as iodine is displaced
What happens when bromine is displaced by chlorine in potassium bromide?
•orange solution formed bromine is displaced
What is the product formed from acid + metal?
Acid + metal to salt + hydrogen
What are the products of metal + water?
Metal + water to metal hydroxide + hydrogen
Reactivity series
Potassium K Sodium Na Lithium Li Calcium Ca Magnesium Mg Aluminium Al Zinc Zn Iron Fe Hydrogen H Copper Cu Silver Ag Gold Au
Equation for rust
Iron + oxygen + water = hydrated iron (III) oxide
Conditions for making oxygen
- hydrogen peroxide
- manganese (IV) oxide catalyst
- Hydrogen peroxide = water + oxygen
What colour flame is formed when magnesium, carbon and sulfur are burned in air?
- bright white
- orange
- pale blue
Flame Tests for cations
- lithium- red
- sodium- yellow/orange
- potassium- lilac
- calcium- brick red
Test for copper and iron
- add NaOH
- copper- blue
- iron (II)- green
- iron (III)- Brown
- ammonium- gives off ammonia
Tests for gases
- ammonia- damp red litmus paper goes blue
- chlorine- damp blue litmus paper goes red then white
- water- anhydrous copper sulfate goes white to blue
Tests for carbonates
- add HCl
* if effervescence then carbonate is present
Sulfate tests
- add barium chloride
* if white ppt fiend then sulfate is present
Halides tests
- add nitric acid and silver nitrate
- cl- white ppt
- br- cream ppt
- I- yellow ppt
Methyl orange
- acid- red
* alkali- yellow
Universal indicator
- acids- yellow/red
* alkali- blue/purple
Litmus paper
- acid- red
* alkali- blue
Phenolphthalein
- acid- colourless
* alkali- pink
