Chemistry Paper 1 Flashcards
Chem: what is the equation for atom economy
Chem: what type of atoms are used in and what happens in covalent bonding
2 or more non-metals, sharing electrons
Chem: what happens in metallic bonding and in what type of atoms
Positive metal ions in a sea of delocalised negative electrons, in metals
Chem: what happens in ionic bonding and in what type of atoms
Gives/takes electrons, metals and non-metals
Chem: what is a activation energy
The minimum energy required to start a chemical reaction
Chem. what is an energy profile
A graph showing energy change during a chemical reaction
Chem: what is an exothermic reaction
A chemical reaction that releases energy
Chem: what is an endothermic chemical reaction
A chemical reaction that takes in energy
Chem: what happens in a chemical reaction
Bonds are broken and formed and atoms are rearranged
Chem: how thick is one nm in terms of atoms
10 atoms thick
Chem: order in terms of size, from smallest to largest, coarse particles, nano particles and fine particles
Smallest - largest: nanoparticles, fine particles, coarse particles
Chem: what is the size of coarse particles
2500 to 10000 nm
Chem: what is the size of fine particles
100 to 2500 nm
Chem: what is the size of nano particles
1 to 100 nm thick
Chem: is the anode the positive or negative electrode in electrolysis
Positive
Chem: is the cathode positive or negative in electrolysis
Negative
Chem: is an anion positive or negative
Negative
Chem: is a cation positive or negative
Positive
Chem: what happenes at the negative electrode in electrolysis of aqueous solutions
Hydrogen forms , only if the metal is more reactive than it
Also electrons transferred to ion to make it an atom
Chem: is electrolysis of aqueous solutions what happens at the positive electrode
Oxygen produced, unless a halogen present then the halogen is produced
Electron transferred from ion to positive electrode
Chem: what is an aqueous solution
Something dissolved in water
Chem: what is the definition of electrolysis
Electrolysis is the process of splitting ionic compounds using electric current
Chem: how do you work out moles of an atom
Moles= mass / formula mass
Chem: how do you work out the formula mass (Mr) of a molecule
It is the sum of the elements in the molecule
Chem: work out the Mr of K ₂O if the formula mass of of K is 39 and O is 16
39+39+16=94
Chem: How do you write ionic equations
Split the equation so
- NaOH ( aq ) + HNO 3 ( aq ) → NaNO 3 ( aq ) + H 2 O ( l )
Would become - Na + OH ( aq ) + H + NO 3 ( aq ) → Na + NO 3 ( aq ) + H 2 + O ( l )
Then cross out the portions that do not change their charge, this becomes
- OH ( aq ) + H → H 2 O ( l )
Chem: what is an ionic equation
It is a chemical equation with all of the things that do not change charge removed
Chem: what is oxidation
Oxidation is the loss of electrons and the gain of oxygen
Chem: what is reduction
It is the gain of electrons and hydrogen and the loss of oxygen
Chem: in electrolysis does reduction or oxidation occur at the positive electrode
Oxidation
Chem: in electrolysis does oxidation or reduction occur at the negative electrode
Reduction
Chem: what is a half equation
Electrons are represented, they are 2 equations that show how electrons are transferred at each electrode in electrolysis
Chem: what is the equation for complete combustion
Hydrocarbon + oxygen -> carbon doxide + water
Chem: what is the equation for incomplete combustion
Hydrocarbon + oxygen -> carbon doxide + water + carbon monoxide
Chem: what is the definition of carbon footprint
this is the total amount of carbon dioxide and other greenhouse gases that are emitted over the full lifecycle of a product, service or event
Chem what is carbon foorptprint offsetting
Say you buy a plane ticket, planting trees to offset the greenhouse gasses released by the journey
Chem: what is the order of events for the formation of life
Volcanoes, oceans, algiae, plants, animals
Chem: what are the percentages of gasses in the atmosphere
Nitrogen-78, oxygen-21, other gasses-1
Chem: what are the 4 alkanes you need to remember
Methane, ethane, propane, butane
Chem: what is crude oil made of
Fossilised plankton
Chem: what is the definition of a mixture
A substance composed of 2 or more differeent compounds or elements not chemically bonded
Chem: what is ionic bonding and in what types of elements does it occur
Giving/taking electrons
Between metals and non metals
Chem: what is covalent bonding and in what type of elements does it occur
Sharing electrons
2 non metals
Chem: what is metallic bonding and in what type of elements does it occur
Sea of delocalised electrons
Metals
Chem: what are the properties of covalently bonded substances
- Non-conductive(no charged particles that can carry a charge)
- low melting point
Chem: what are the properties of ionically bonded substances
Conduct when dissolved in water, hard and brittle, high melting and boiling points.
Chem: what defines potable water
It is safe to drink, it should have low levels of dissolved salts and of microbes.
Chem: what are the 2 ways of getting potable water from salt water
Distillation , reverse osmosis
Chem: what is reverse osmosis
It is osmosis where the water moves from low to high concentration because of large amounts of pressure
Chem: what is distillation
Where a liquid is evaporated and collected from a mixture
Chem: what are the 3 ways water us steralized
UV, chlorine, ozone
Chem: what is pure water
Water that is not in a mixture
Chem: how many cm3 in a dm3
1000
Chem: how do catalysts work
They change the reaction pathway
Chem: what are the 5 factors that affect rate of reaction
-temp
-concentration
-catalyst
-pressure
-surface area
Chem/bio: how do enzymes make things react
They lower the activation energy
Chem: what is a the difference between weak and strong acids
Weak acids have low amounts of ionised hydrogen ions, whereas in strong acids there is a large amount of ionised hydrogen ions
chem: what is a mole
1 mol is the amount of substance that contains the same number of particles as there are atoms in 12.0 g of carbon-12, its the 6.02 x10^23 atoms of carbon 12
chem: what is percentage yield
actual yield / theoretical yield x 100
chem: what is the equation for relative formula mass
adding up all of the relative atomic masses of the atoms in a formula
Chem: what is the difference in amount of hydrogen ions between PH 2 and PH 1
10x, each jump is a gap of 10x as it is what i think is a log arythem
Chem: what hydrogen ions constitute acids, are they positive or negative
H+ ions
Chem: what hydrogen ions constitute alkalise, shat charge are they
OH- ions
chem: in electrolysis does reduction happen at the cathode or anode
cathode
chem: in electrolysis does oxidation happen at the cathode or anode
anode
Chem: what is the difference between giant and simple covalent bonding
Simple covalent - fixed number of atoms in the structure, giant covalent - undefined amount of atoms.
Chem: why do simple covalent compounds have low melting and boiling points
The have weak intermolecular forces, this means less energy is needed to overcome these forces
Chem: what is the difference between atomic and intermolecular forces
Atomic forces are forces within an atom and intermolecular forces are the forces between atoms.
Chem: what are the properties of simple covalent compounds
Low melting and boiling point, do not conduct
Chem: what are the properties of giant covalent
High melting and boiling point.
Chem: what are the properties of ionic compounds
High melting and boiling points, when molten or dissolved the conduct, when solid the have poor conductivity