13272679
Description
Flashcards by I Shouldn't be awake, updated more than 1 year ago
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Created by I Shouldn't be awake
about 6 years ago
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| Question | Answer |
| Atomic Number | Number of protons Number of electrons |
| Atomic Mass | Number of protons Number of neutrons |
| C-12 | Standard mass of 1u is 1/12th the mass of an atom of C-12 |
| RIM | Mass of an isotope relative to 1/12th the mass of a C-12 atom |
| RAM | Weighted mean mass of an atom of an element relative to 1/12th mass of C-12 Ar Takes into account % abundance of each isotope RIM of each isotope |
| Determining RAM | 1. Sample placed in mass spectrometer. 2. Vaporised, ionised to form ions. 3. Ions accelerate, heavier more more slowly 4. Ions detected on a mass spectrum as a m/z ratio |
| Determining RAM formula | (%*mass)+(%*mass)/100 |
| Polyatomic ions (2) | Nitrite NO2- Sulphite SO3 2- |
| What is avogadro constant? | 6.02*10^23 # Particles in 1 mole of C-12 |
| Molar mass unit | gmol-1 mass per mole of a SUBSTANCE |
| EF | Simplest whole-number ratio of atoms of each element in a compound Important for substances that don't exist as molecules, e.g. crystals |
| MF | EF/Mr of compound Number of atoms of each element in a molecule |
| Relative molecular mass | Mr Mass of a molecule with the mass of an atom of C-12 |
| Relative formula mass | Mass of a formula unit with the mass of an atom of -12 e.g. NaCl =58.5 |
| Working out formula of hydrated salts | Mass of anhydrous/Mr Mass of H2O/18 |
| Assumptions made | 1. All H2O lost. 2. No further decomposition. |
| 1 mol dm-3 | 1 mole of solute in 1dm3 solution |
| Standard solutions | Dissolving a known mass of solute in solvent and making solutin up to an exact volume |
| Steps (3) | 1. Work out amount of moles required. 2. Work out Mr 3. Work out mass by n*Mr |
| Vm | ~20'C 101kPa Vm = 24 dm-3 at RTP N=V/Vm |
| Ideal gas assumptions (RENN) | Random motion Elastic collisions Negligible size No IM forces |
| Ideal gas equation | Pv=nRT Pressure (Pa) m3 moles 8.31 J mol-1 K-1 K As long as you know 3 of Pv/n/T/ you can work out the rest. |
| Conversions | cm3->m3 *10^-6 dm3->m3*10^-3 |
| ideal gas rearrangement for T | pV/nR Room T = 19'c |
| Stoichiometry | Ratio, in moles, of each substance. 2H2 + O2 -> 2H2O 2 mol 1 mol 2 mol |
| Percentage yield | Tells you how much of the theoretical max amount of product you've attained from the reaction actual/theoretical *100% |
| Limiting reagent | Reagent that's not in excess |
| Atom economy | Sum of desired product Mr / Sum of all products *100 |
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