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Stoichiometry
The Atomic Structure, Electrons and Orbitals
Chemical Bonding
Kinetics
Organic Chemistry - Naming
100
The molar mass of NaCl is 58.5g. How many moles of salt are present in 462g?
7.90 moles of NaCl.
100
What is the frequency of a wave with wavelengths 5.20 x 10-9m? What is its energy?
5.77 x 1016 Hz or s-1 and 3.82 x 10-17 J respectively.
100
Carbon and chlorine form a series of compounds, CH4, CH3Cl, CH2Cl2, CHCl3 and CCl4. Which of these are polar?
CH3Cl, CH2Cl2, and CHCl3
100
Iodate(V) ions oxidize iodide ions in acidic solutions to form iodine and water according to: IO3-(aq) + 5I-(aq) + 6H+(aq) --> 3I2(aq) + 3H2O(l) If the number of moles of each reactant consumed after one minute was measured, which would have been consumed least?
IO3-
100
Jady named this compound 3-butylpentanoic acid. Why is she wrong and what is its actual name? See picture.
She did not count the longest chain: 3-ethylheptanoic acid.
200
According to the formula: 2H2 + O2 --> 2H2O, what is the limiting reagent and how much H2O will be produced given 9.00g H2 and 10.52g O2
O2 is the limiting reagent. 11.9g of H2O will be produced.
200
Explain what are the Balmer series, Lyman series and Paschen series.
They are the names of groups of specific types of waves: Balmer is visible emission spectrum, Lyman is ultraviolet light (an energy "drop" larger than n=6 to n=2), Paschen is infrared light (an energy drop smaller than n=3 to n=2).
200
Which of the following contain both ionic and covalent bonds? SiO2, BaF2, Na2CO3, and Cl2O
Na2CO3
200
Why does the efficiency of a catalyst decrease with time?
It becomes inactive due to impurities in the reaction mixture, side reactions, or its surface becomes coated.
200
Draw the structure of 2-amino-2,3-difluoropentanol.
See picture.
300
Gypsum is a naturally occurring form of calcium sulfate (CaSO4 • 2H2O). What percentage by mass of gypsum is water? Ca = 40.08g mol-1 S = 32.06g mol-1 O = 16.00 g mol-1 H = 1.01g mol-1
What is 20.93% water.
300
Explain Hund's Rule and the Aufbau Principle.
Hund's Rule: Orbitals of the same type will fill singularly first. I.e. There are 3 p orbitals at one energy level. Each p orbital will have one e- before they receive their second e-. Aufbau Principle: Orbitals of lowest energy will be filled first. I.e. Since d orbitals are higher energy than the s orbitals of the next energy level, the s orbitals will fill first --> 4s2 before 3d starts to fill.
300
Sulfur tetrafluoride. Name its shape, give all angles and how many non-bonding electron pairs are there?
Saw horse, 90 and 117 degrees, and one non-bonding electron pair.
300
Suppose that for the reaction 2A + B --> C , experiments revealed that m = 2 and n =1, so that the rate at which C forms = k[A]2[B]1. What would happen to the rate at which C formed if [A] tripled and [B] remained constant?
The rate would increase by a factor of 32 = 9 because the rate is proportional to the square of the concentration of A.
300
Which of the following has the highest boiling point? a) CH3-COOH b) CH2(CH3)CH2CH2COOH c) CH3CH(Cl)CH3 d) CH3C(CH3)2CH3
b) CH2(CH3)CH2CH2COOH H-bonding and largest molecule.
400
When hydrogen peroxide is added to a manganese(IV) oxide catalyst, it undergoes catalytic decomposition to water and oxygen. What volume of oxygen, measured at standard temperature and pressure, can be produced from a solution containing 17g of hydrogen peroxide?
5.6dm3 oxygen.
400
Give the core notation of chromium and vanadium 2+, and the expanded form of Phosphorus.
Cr = [Ar]4s1, 3d5 V2+ = [Ar]3d3 P = 1s22s22p63s23p3
400
Explain in terms of the intermolecular forces that exist, why water is a liquid at room temperature but hydrogen sulfide is a gas.
Water has H-bonding therefore molecules are held tightly together and not spread apart as a gas. Hydrogen sulfide does not have H-bonding because it is not polar-covalently bonded to a very electronegative element. Only dipole-dipole forces and Van der Wal's forces apply to hydrogen sulfide.
400
A reaction involves 2 reactants A and B. The following results were obtained at 25C:
8x10-3 mol-1 dm3s-1
400
Draw and name the functional isomers of butanoic acid.
Methyl propanoate, ethyl ethanoate, propyl methanoate. See picture.
500
Vitamin C, a compound of C, H, and O only, is found in many fruits and vegetables. The percent by mass of C, H, and O are determined by burning a sample of vitamin C weighing 2.00mg. The masses of CO2 and H2O formed are 3.00mg and 0.816mg respectively. By titration, its molar mass if found to be at about 180g mol-1. Determine the molecular formula of vitamin C.
What is C6H8O6
500
Give the electron configuration of Cu2+ and an isoelectronic species.
Cu2+ = 1s22s22p63s23p63d9 Co = 1s22s23s23p64s23d7
500
Describe how a non-polar solvent, such as tetrachloromethane, could be used to separate a mixture of magnesium and iodine into its components.
The solvent is soluble with iodine but not with magnesium metal therefore magnesium is undissolved.
500
The activation energy of a chemical reaction can be determined by measuring the effect on reaction rate of varying: temperature, [reagents], [catalyst] or the surface area in contact.
Temperature.
500
Which of the following is optically active? Draw the structure and label its chiral carbon. a) 2-amino-2-methylethanoic acid b) 2,2-difluoropropane c) propanenitrile d) chloro-fluoromethane
See picture.