Exam Notes Flashcards
Explaining diffusion
Don’t confuse with rates technique
Separating a mixture containing salt and water
Simple distillation
Preparation of CO2
Tap funnel
Colour change when CuCO3 thermally decomposed
Green > black
Rust reactions
Take a week
Nitric acid
HNO3
Water of crystallisation
Heat to constant mass to ensure all of the water has been removed from the crystals
Iconic substances don’t conduct when solid
Particles only vibrate
Electrolysis
Refer to ions
Gold
NOT too unreactive, just does not react
Use excess
Because…. JEM HELP!!
Ion which caused solutions to be acidic
H+
Flame test
Dip platinum/nichrome wire in HCl
When naming substance responsible for observations
Name compound (not ion!)
Energy level diagrams
ΔH is the vertical line
Ea is the bump (draw straight line next to it as label)
Q
Remember to add volumes of acid and alkali
Calorimetry variables
Distance, insulation
Why is percentage yield small in reversible reactions?
Dynamic equilibrium was not reached
Crude oil enters the column,
heated, until it is vaporised
Fraction with the largest molecules
Bitumen
When drawing ester functional group
Include other bonds
Control variables
If in doubt, use MOLES not mass
Why repeat?
To take a mean average, help identify anomalous results and obtain reliable results
Ethanol used instead of water in solutions because
it’s a better solvent
How to heat flammable liquids
In a water bath
Chromatography original dot
Doesn’t appear in after diagram
Also label spots
Temperature in rates
More successful collisions per unit time!!
SA rates
Temperature increases because more energy transferred to mixture
Volume affect on temperature change
Increase in volume decreases temperature change because there is more to heat up
Why use distillation
Smaller / bigger BPs
Equilibrium
Concentration of reactants and products remain constant
Endothermic reactions
Release thermal energy
Ionic substances and melting points
Define ionic
Mention oppositely charged ions
Substance responsible for bubbles
Not ion
Substance
Calculating empirical formula
Percentage / RFM
No temperature decrease in neutralisation at higher volumes
Volume of acid larger
Condensation polymerisation
Involves loss of water molecules
Biodegradable
Can be broken down by bacteria
Method of separation for separating copper(II) sulphate from a mixture with water
Crystallisation
Leave chromatogram until
Solvent front reaches top of paper
AgCl
Prevents false positives by preventing other precipitates from forming
Why do you relight flame in reduction of metal oxides
Hydrogen poses risk of explosion
What steps are taken to confirm an accurate value for the mass of a metal
Heat solid again, reweigh to check constant mass
Rock salt equipment
Evaporating basin
Why is the mixture of rock salt and water warmed and stirred
Sodium chloride dissolves more quickly
Colour of halogens afterwards
Always colour of element
Crystallisation method
1) heat until crystals form
2) cool
3) filter of crystals
4) dry crystals using filter paper
Obtaining pure, dry water from sea water
Simple distillation
Properties of carbon
High melting point
Giant structure
Using a Burette
Acid must be added before
Better resolution
Why is there no reaction between a metal and acid
Think about reactivity
Repeats
Increase validity
Dynamic equilibrium
Rates of forwards and backwards reactions are equal
Order of reactivity in halogen reactions
Have they been vaporised?
Magnesium ribbon
Silver solid strip
Lithium removed from oil, dried and cut
The exposed surface….
Changes from shiny to dull
Metal + water
Metal hydroxide + hydrogen
Exothermic reactions
Reactant temperature increases
Universal indicators in weak acids
Orange-yellow
Carbonic acid
H2CO3
How to figure out which of two solutions has a greater concentration when given volume and equation
Compare molar ratio with volumes
Galvanising
Zinc
Simple distillation equipment
Flask
Why is iron powder mixture with water when creating oxygen
Too slow without water
How to calculate percentage of oxygen in air
Volume of oxygen reacting x 100
Divided by total volume of air in conical flask, glass tube and syringe reading at start
Bromine + sodium iodide
Displacement -> solution becomes darker
Why is a glass rod used in heated solutions
To see if crystals form, indicates crystallisation point
Why is solution heated
To evaporate water (to reach crystallisation point)
Label above tripod in distillation
Gauze
Group
Column - same number of outer-shall electors
CO2 production
Stops because insoluble CaSO4 coats the marble chips
Condensation
Discuss cooling
Zinc solutions
Colourless
Copper colour
Brown
Reasons for anomalous results in precipitation
- start mass to small
- to little reactant
- precipitate not left to settle for long enough
ANHYDROUS copper(II) sulphate
Nice
Preparation of water
Collect using gas syringe
Is a solution more acidic or more alkali?
Is one solid?
Nitric acid
Removes carbonate and sulfite ions
Crude oil separating in a
Fractionating column
Cotton wool
Stops liquid escaping, let gas escape
Control variables for CaCO3 + HCl
Mass
Surface area
