Modern Roaming for Notes and Nomad – Cheaper Faster Better Stronger
The mini definitive chemistry guide
1. THE MINI
DEFINITIVE
CHEMISTRY GUIDE
Disclaimer: May not be that definitive,
calculator may be needed for some of
the questions.
Definition Ion Question
Equations
s formulae s
2. GLOSSARY
Avagadro’s Constant Waters of Proton Number
Crystallisation
Molar Mass Relative isotopic mass
Combustion
Amount of Substance Relative atomic mass
Acid
Mole Mass spectrum of element
Alkali
Empirical Formula Valency (not required for
Base exam)
Molecular Formula
1st Ionisation Energy Isotope
Anhydrous
2nd Ionisation Energy
Hydrated
Orbital
3. AVAGADRO’S CONSTANT
The number of particles in a mole. (6.02x1023)
MOLAR MASS
The mass per mole of a substance (gmol-1)
AMOUNT OF SUBSTANCE
The quantity who’s unit is the mole (mol)
Back to
glossary
4. MOLE
The amount of any substance containing the same amount of
particles as there are carbon atoms in 12 grams of carbon 12
isotope.
EMPIRICAL FORMULA
The simplest whole number ratio of atoms of each element in a
compound.
MOLECULAR FORMULA
The actual number of atoms of each element in a molecule.
Back to
glossary
5. ANHYDROUS
A substance that contains no water molecules
HYDRATED
A crystalline compound that contains water molecules
WATERS OF CRYSTALLISATION
Water molecules that form part of the crystalline structure of the
compound
Back to
glossary
6. COMBUSTION
When a substance reacts with O2 to form its oxides.
ACID
A proton donor (H+)
ALKALI
A substance that dissolves in water to release OH- ions
Back to
glossary
7. BASE
A proton receiver (H+)
1ST IONISATION ENERGY
The amount of energy required to remove 1 mole of electrons
from 1 mole of gaseous atoms
2ND IONISATION ENERGY
The amount of energy required to remove 1 mole of electrons
from 1 mole of gaseous +1 ions
Back to
glossary
8. ORBITAL
A region of space that holds up to 2 electrons with opposite spins
PROTON NUMBER
The number of protons in the nucleus
RELATIVE ISOTOPIC MASS
The mass of an atom of an isotope relative to 1/12 of carbon-12
Back to
glossary
9. MASS SPECTRUM OF AN ELEMENT
… Shows the relative isotopic mass of each isotope of an element
and their abundance
RELATIVE ATOMIC MASS
The weighted mean mass of an element relative to 1/12 of carbon
12
VALENCY (NOT REQUIRED FOR
EXAM)
The number of atoms an atom has the affinity to bond with. In
other words the amount of holes in an atom in a modelling kit. to
Back
glossary
10. ISOTOPE
Contains the same number of protons (and electrons) but different
number of neutrons.
Back to
glossary
11. EQUATIONS
Mass = Moles * Molar mass (Mr) (mass g, moles mol, Mr gmol-1)
Gdm-3 = Mol dm-3 * Mr (Gdm-3 and mol dm-3 = ditto, Mr gmol-1)
Moles = Concentration * Volume (Moles, mol Concentration gmol-
1 or mol dm-3 , Volume = dm3
Volume = Moles * 24 (volume dm3, moles mol, 24 = dm3 mol-1)
Acid + Alkali Salt + Water
Metal oxide + Acid Salt + Water
Metal + Acid Salt + H2
Ammonia (NH3)+ Acid Salt
Carbonate + Acid Salt + Water + CO2
13. 1) What is the definition for “1st ionisation energy”?
Reveal answer
The amount of energy required to remove 1 mole of electrons
from 1 mole of gaseous atoms
2) When given moles and concentration, how do you calculate
volume? Reveal answer
Moles = Conc * Vol, so Vol = Mol / Conc
3) What is the valency of carbon?
Reveal answer
4. It is a sneaky question, but think back to biology lessons with
the modelling kits ;)
Next set of questions Remember
score out
of 3 for
later
14. 4) When given 24 and moles, what can you calculate? (and
how?)
Reveal answer
Moles * 24 = Volume. (Only for gasses at RTP)
5) What is the definition of “waters of crystallisation”
Reveal answer
Water molecules that form part of the crystalline structure of the
compound
6) As well as the obvious difference of “contains water molecules” and
“contains no water molecules”, what is the difference between
“anhydrous” and “hydrated”? (recite definitions mentally)
Reveal answer
Ouch, tough one. Remember “an” meaning “exempt”? So an
anhydrous substance is “exempt” from being a crystalline
molecule.
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6)
15. 7) What are the ionic formulae (with charges) for Nitrate +
Nitride?
Reveal answer
Nitrate = NO3-
Nitride N3-
8) What is the definition of “Alkali”?
Reveal answer
A substance that dissolves in water to release OH- ions
9) Calculate the volume of 15 g dm-3 calcium chloride
required to give 0.150 moles. (hint, you need 2 triangles)
Reveal answer
1.10 dm3. Follow THIS LINK for the workings.
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9)
16. WORKED QUESTION 9
First write out the chemical formula. CaCl2. (Remember ionic
charge)
You have been given the g dm-3. You need 2 numbers to use any
of the 4 triangles. So what else can you work out from the
question?
The Mr of the compound! (which is 40.1 + 35.5*2)
G dm-3 divided by Mr gives mol dm-3. (0.135)
So how can you calculate volume from mol dm-3? Well split up
mol and dm3. You have 1 dm3, and 0.135 0.135 The question
3
moles.
Use
same
asks 1 dm many dm3 make 0.15 moles. So moles of it this way…to 0.150
how think From 0.135
= *by 1.1 recurring.
number (click anywhere to cont) (0.150 / 0.135. New
(multiply 0.150 over old.)
1 by 1.1 Answer moles
recurring
) Back to Q9
17. 10) What is the definition for “orbital”?
Reveal answer
A region of space that holds up to 2 electrons with opposite spins
11) What is the definition for “Isotope?”
Reveal answer
Contains the same number of protons (and electrons) but different
number of neutrons.
12) What mass of MgO is formed by the complete
combustion of 24 g of Magnesium
Reveal answer
First balance the equation to get 2Mg + O2 2 MgO
You have 24 g of magnesium. You need the moles. 24 / 24.3 = 0.987… mol
0.987 * (24.3 + 16) = 39.8 g
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18. 13) Metal + Acid What?
Reveal answer
Salt + Hydrogen gas
14) Metal oxide + Acid what?
Reveal answer
Salt + Water. Logical as the only difference is the insertion of a
water molecule into the metal.
15) What is the definition of “Empirical Formula”?
Reveal answer
The simplest whole number ratio of atoms of each element in a
compound.
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15)
19. 16) What is the definition of “molar mass”?
Reveal answer
The quantity (of a substance) who’s unit is the mole
17) When 14.2 g of hydrated nickel (11) nitrate is dried, 8.9 g
remains. Find x in Ni(NO3)2 . X H2O
Reveal answer
X = 6. Find the mass of water, and of nickel nitrate. Then use
mass = moles * Mr to find the moles. Divide both by smallest
18) What are x. ionic formulae for a) carbonate b)
moles to get the
hydrogen carbonate?
Reveal answer
Carbonate = CO3 2-
Hydrogen Carbonate = HCO3-
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18)
20. 19) What is the definition of “mole”?
Reveal answer
The amount of any substance containing the same amount of
particles as there are carbon atoms in 12 grams of carbon 12
isotope.
20) What is the definition of “relative isotopic mass?”
Reveal answer
The mass of an atom of an isotope relative to 1/12 of carbon-12
21) X + Acid Salt + Water + CO2
Reveal answer
Carbonate.
Next Continue…
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21)
21. THE MOMENT OF TRUTH, YOUR
SCORE…
90% +
Fantastic!
A*
80% +
Great!
A
70% +
…
B
60% +
Never!
C