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How is an element in the periodic table labelled?
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The hypothesis that chemical substances are made of atoms is motivated by the observation that....
...compounds result when elements combine in simple, fixed proportions
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Equal volumes of gases (at the same temp + pressure) have equal numbers of...
Gas molecules
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Equation that relates the energy of a photon to its frequency
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Simple diagram explaining constructive and destructive interference between two waves of identical frequency and amplitude
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Oxidation of pyrite  How many moles of H+ will be generated from the oxidation of 3.7g of pyrite? Atomic masses: Fe = 55.9, S = 32, H = 1
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Photosynthesis:
How many grams of CO2 will be consumed by the production of 1kg of biomass? Atomic masses: C = 12, O = 16, H = 1
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Seawater has a salinity of 3.5 x 10^-2 mg NaCl per mm^3. What is the concentration of NaCl in moles/L? Atomic masses: Na = 23, Cl = 35.5
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A mineral has the composition Fe (46.6%) and S (53.4%). What is the chemical formula of the mineral? Atomic masses: Fe = 55.9, S = 32
- Assume you have 100g of the mineral then:
- 46.6/55.9 = 0.833 mol Fe
- 53.4/32 = 1.66 mol S
- 1.66/0.833 ≃ 2
Formula: FeS2
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How many molecules of CO2 are in 1g of CO2? Avogadro's number = 6.022 x 10^23
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A substance is oxidised when it...
Loses electrons
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A substance is reduced when it...
Gains electrons
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In the following reaction is Mn oxidised or reduced?
Mn is reduced
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What is the oxidation state of sulfur in (SO4)2-?
+6
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What is the oxidation state of Fe in Fe2O3?
+3
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What is the oxidation state of As in (AsO3)-3?
+3
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The pK for the half-reaction is -41.4. What is the pe of a lake of water in equilibrium with MnO2 at pH 6 with a dissolved Mn2+ concentration of 10^-5 m?
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The pK for the half-reaction is -2.7. What is the pe of a lake of water in equilibrium with [Cu2+]/[Cu+] = 1?
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Work out the electronic configuration for Al (atomic number 13).
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Work out the electronic configuration for P (atomic number 15).
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Work out the electronic configuration for Ti (atomic number 22).
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Sulfur can lose 6 electrons to adopt a closed shell configuration and a +6 oxidation state. Why won't oxygen lose 6 electrons to get the closed-shell configuration?
Oxygen is too electronegative.
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Out of O, Cl, S, C, Si, Mg and Ca, which pair of atoms should form the most ionic bond?
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Out of O, Cl, S, C, Si, Mg and Ca, which pair of atoms should form the most covalent bond?
- Any like pair (e.g.O-O)
- Any adjacent pair (e.g. O-Cl or C-S)
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Predict which ions might substitute for Fe2+ in olivine.
Ni2+, Co2+ and several other 2+ transition metals.
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Draw the Lewis structure for CH4.
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Draw the Lewis Structure for NH3.
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Draw the Lewis structure for SiF4.
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For write an expression for pe in terms of pH and pK.
- pK = -pe - pH
- pe = -pK - pH
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Using Pauling's 1st rule, try to predict the coordination number of the cations in CaO.
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| | | Ca Coordination Number | | | |
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| Oxygen coordination number | | 6 | 7 | 8 | 12 | | | 2 | 0.74 | 0.79 | 0.83 | 0.99 | | | 4 | 0.72 | 0.77 | 0.81 | 0.97 | | | 6 | 0.71 | 0.76 | 0.80 | 0.96 | | | 8 | 0.70 | 0.75 | 0.79 | 0.94 |
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MgO adopts the NaCl/B1 structure. There are 4 formula units in each unit cell. Using the ionic radii of Mg2+ (VI) and O2- (VI) preditc the density of Mgo. Atomic masses: Mg = 24.3, O = 16
- p = m/v
- Mass:
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How many lead atoms are there in 1cm3 og Pb3O4? Density of Pb3O4 is 8300kg/m3. Atomic masses: Pb = 207.2, O = 16
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In the mineral corundum (Al2O3) the coordination number of Al is 6. Use Pauling's 2nd rule to work out the coordination number of the O2- ion.
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According to Pauling's 1st rule, in an ionic crystal structure, the coordination number of a cation by its surrounding anions is determined by...
...the ratio of the cation and anion radii
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