Practice MDCAT Chemistry questions with answers and explanations.
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The rate depends on the square of concentration.
Doubling gives 2²=4 times the rate.
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Transition-metal chemistry arises from partially filled d orbitals.
Common features include variable oxidation states and colored ions.
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Four oxygens contribute -8 total.
Sulfur must be +6 so the ion total is -2.
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Ligands split d-orbital energies.
Absorption of selected visible wavelengths gives the observed complementary color.
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Oxidation numbers sum to the overall charge of the species.
Applying standard rules gives the stated value.
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Use E°cell=E°cathode-E°anode.
0.80-(-0.40)=1.20 V.
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Oxygen is the most abundant element in Earth's crust by mass.
It occurs mainly in oxides and silicate minerals.
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Aluminum is the most abundant crustal metal.
It is commonly found in aluminosilicate minerals and bauxite.
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Alkali metals have one valence electron.
They usually lose it to form +1 ions.
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Group 2 metals have two valence electrons.
They commonly lose both and form +2 ions.
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Filled valence shells are especially stable.
Noble gases therefore have little tendency to gain or lose electrons.
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Fluorine has very high electronegativity and a weak F-F bond.
It is the strongest elemental oxidizing halogen.
