Atoms of the same element with different numbers of neutrons and different masses.
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Define relative isotopic mass.
The mass of an isotope relative to 1/12th of the mass of an atom of carbon-12.
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Define relative atomic mass.
The weighted mean mass of an atom of an element relative to 1/12th of the mass of an atom of carbon-12.
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What is mass spectrometry used for?
To determine the relative isotopic masses and relative abundances of the isotopes. To calculate the relative atomic mass of an element from the relative abundances.
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Define relative molecular mass.
The average mass of a molecule compared to 1/12th of the mass of an atoms of carbon-12. Can be referred to as molar mass.
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How is the relative atomic mass calculated?
Multiply each relative isotopic mass by its % abundance and add up the results, then divide by a 100.
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What is amount of substance?
The number of particles in a substance, measured in moles (n). There are 6.02x10^23 particles in one mole (Avogadro constant)
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What is the formula to calculate moles (n)?
n = mass of substance (m) / molar mass (Mr) OR n = concentration x volume(dm3) or ( volume(cm3)/1000)
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What is the formula to calculate moles (n) of gas?
n = volume (in dm3) / molar gas volume (24dm3) or volume (in cm3)/ molar gas volume (24000 cm3)
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Define empirical formula.
The simplest whole number ratio of elements in a compound.
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Define molecular formula.
The number and type of atoms of each element in a molecule.
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Define anhydrous.
Containing no water molecules.
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Define hydrated.
Containing water molecules.
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Define water of crystallisation.
Water molecules that are bonded into the crystalline structure of a compound.
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What is the method to calculate the formula of a hydrated salt?
Find the amount of anhydrous salt, calculate the mass and amount of water formed, find the smallest whole-number ratio.
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What is the ideal gas equation?
pV = nRT
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Give units for each component in the ideal gas equation.
p - Pa, V - m3, n - mol, R - Jmol-1K-1, T - K
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What is stoichiometry used for?
To find the ratio of each substance present in an equation, e.g 2:1 moles of H:O in H2O
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What is the percentage yield?
The conversion of starting materials into desired materials. percentage yield = actual yield (n) / theoretical yield (n) x 100%
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What is the atom economy?
A measure of how well atoms have been utilised. If atom economy is high: large proportion of the desired products was made with little waste products. atom economy = sum of molar masses of desired products/ sum of molar masses of all products x 100%
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Describe strong acid.
Fully dissociates (Releases all of its hydrogen ions - only when aqueous)
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Define a Bronsted-Lowry acid
Proton donor.
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Describe weak acid.
Partially dissociates (releases a small proportion of its hydrogen ions - only when aqueous)
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Define a Bronsted- Lowry base
Proton acceptor (releases OH- ions into the solution - only when aqueous)
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Give the formula of: 1 - hydrochloric acid, 2 - sulfuric acid, 3 - nitric acid, 4 - ethanoic acid
1 - HCl, 2 - H2SO4, 3 - HNO3, 4 - CH3COOH
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Give the formula of: 1 - Sodium Hydroxide, 2 - potassium oxide, 3 - ammonia
1 - NaOH, 2 - KOH, 3 - NH3
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Describe neutralisation of acids with bases.
Hydrogen ions react with a base to form a salt and neutral water.
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Describe neutralisation of acids with metal oxides and hydroxides.
Acid + metal oxide/hydroxide = salt + water
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Describe neutralisation of acids with carbonates.
acid + carbonate = salt + water + carbon dioxide
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Define titration.
A technique used to accurately measure the volume of one solution that reacts exactly with another solution. Used to: identify unknown chemicals, find conc. of solutions or to find purity of substances.
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Define standard solution.
A solution of a known concentration.
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What is a volumetric flask?
Equipment used to make up a standard solution very accurately.
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Describe an acid-base titration.
A solution of an acid is titrated against a solution of a base using a pipette and a burette.
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What does OILRIG stand for?
Oxidation is loss (of electrons) and results in increase in oxidation number, Reduction is gain (of electrons) and results in decrease in oxidation number.
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What do roman numerals indicate?
The magnitude of the oxidation number when an element may have compounds/ions with different oxidation numbers.
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Other cards in this set
Card 2
Front
Define relative isotopic mass.
Back
The mass of an isotope relative to 1/12th of the mass of an atom of carbon-12.
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