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17 Cards in this Set
- Front
- Back
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Theoretical Yield
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moles x Mr
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Percentage Yield
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Actual yield
Theoretical yield |
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Atom Economy
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Masses of products
Mr of reactants |
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Limiting Reagent
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Find Mr of one reagent
Find Mr of other Use mole:mole to find moles of product LR least no. moles |
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What is a Mole?
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Amount of substance which contains the same number of particles (atoms) as there are atoms in 12g Carbon
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Atomic mass (Ar)
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The mass of 1 mole of an element in gmol-1
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State Hess' Law
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The enthalpy change of a reaction is independent of the route taken
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Enthalpy of Formation ΔHf
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- The enthalpy change when 1 mole of substance is formed from its constituent elements in their standard states
- Under standard conditions - (1atm pressure, 25C or 298K) |
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Enthalpy of reaction ΔHr
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The enthalpy change when reaction occurs in the molar quantities as written under standard conditions in standard state
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Heat Produced =
mass x heat capacity x ΔT |
Error:
- Slow reaction so heat lost to surroundings - Heat absorbed by metal and thermometer |
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Enthalpy of combustion ΔHc
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The enthalpy change when 1 mole of compound is completely burnt in oxygen
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Sources of error of finding ΔHc
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> Takes long time so not all heat lost compensated by extrapolation
> Heat released heats up air > Beaker absorbs some heat > Fuel may not burn completely (incomplete combustion) > Some fuel evaporates |
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Enthalpy of Neutralisation ΔHneu
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Enthalpy change when 1 mole of water is formed from the neutralisation of H+ ions by OH ions
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Enthalpy of atomisation
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Enthalpy change when 1 mole of gaseous atoms is formed from an element in its standard state
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Bond enthalpy:
CH4(g) → C(g) + 4H(g) Mean Bond |
= bonds broken - bonds made
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Soluble Compounds
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Group metal 1
Ammonium compounds Nitrates Chlorides ex Ag and Pb Sulphates ex SR, Ba and Pb |
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Insoluble Compounds
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Carbonates ex group 1 and ammonium
Hydroxides ex g1, ammonium, Ba, Sr, and Ca |
