Download AP Review Chp 1 and Chp 2 Wed 10/9/2013 1. Near room

AP Review Chp 1 and Chp 2 Wed 10/9/2013
1.
Near room temperature, the density of water is 1.00 g/mL, and the density of ethanol (grain alcohol) is 0.789 g/mL. What volume of
ethanol contains the same number of molecules as are present in 225 mL of H2O?
2.
A student wants to determine the empirical and molecular formulas of a compound containing only carbon, hydrogen, and oxygen. To do
so, he combusted a 0.625 g sample of the compound and formed 1.114 g of CO2 and 0.455 g of water. An independent analysis indicated
that the molar mass of the compound is 74.1 g/mol. What are the empirical and molecular formulas of this compound?
3.
Crystals of hydroxyapatite, Ca10(PO4)6(OH)2, provide the hardness associated with bones. In hydroxyapatite crystals, what is (a) the percent
calcium and (b) the percent phosphorus?
4.
Ammonium nitrate, NH4NO3, and urea, CH4N2O, are both commonly used as sources of nitrogen in commercial fertilizers. If ammonium
nitrate sells for $2.95/lb and urea for $3.65/lb, which has the more nitrogen for the dollar?
5.
Vinegar is 5.0% acetic acid, C2H4O2, by mass. (a) How many grams of acetic acid are contained in 143.7 g of vinegar? (b) How many
pounds of acetic acid are contained in 143.7 pounds of vinegar? (c) How many grams of sodium chloride, NaCl, are contained in 34.0 g of
saline solution that is 5.0% NaCl by mass?
6.
Complicated chemical reactions occur at hot springs on the ocean floor. One compound obtained from such a hot spring consists of Mg, Si,
H, and O. From a 0.301-g sample, the Mg is recovered as 0.104 g of MgO; H is recovered as 23.1 mg of H2O; and Si is recovered as 0.155
g of SiO2. What is the simplest formula of this compound?
7.
When she discovered that a piece of shiny gray zinc was too large to fit through the opening of an Erlenmeyer flask, a student cut the zinc
into smaller pieces so they would fit. She then poured enough blue copper chloride solution into the flask to cover the zinc pieces. After 20
min the solution became colorless, the bottom of the flask was slightly warm to the touch, the zinc pieces were visibly reduced in size, and
brown granular material appeared in the mixture. List the physical properties, physical changes, and chemical changes the student should
have noted and recorded in her laboratory notebook.
8.
In some solar-heated homes, heat from the sun is stored in rocks during the day and then released during the cooler night. (a) Calculate the
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amount of heat required to raise the temperature of 69.7 kg of rocks from 25.0 C to 41.0 C. Assume that the rocks are limestone, which is
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essentially pure calcium carbonate. The specific heat of calcium carbonate is 0.818 J/g C. (b) Suppose that when the rocks in part (a) cool
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to 30.0 C, all the heat released goes to warm the 10,000 ft3 (2.83 x 105 L) of air in the house, originally at 10.0 C. To what final
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temperature would the air be heated? The specific heat of air is 1.004 J/g C, and its density is 1.20 x 10 g/mL.
AP Review Chp 3 Tue 10/8/2013
I) Magnesium displaces copper from a dilute solution of copper ( II) sulfate; the pure copper will settle out of the solution.
Mg(s) + CuSO4(aq) MgSO4(aq) + Cu(s)
A copper(II) sulfate solution is mixed by dissolving 25.000 g of copper(II) sulfate, and then it is treated with an excess of magnesium
metal. The mass of copper collected is 8.786 g after drying. Calculate the percent yield of copper.
II) In a particular experiment, 225 g of phosphorus, P4, reacted with excess oxygen to form tetraphosphorus decoxide, P4O10, in 89.5% yield. In a
second step reaction with water, a 97.8% yield of H3PO4 was obtained.
(a) Write the balanced equations for these two reaction steps.
(b) What mass of H3PO4 was obtained?
III) What is the molarity of a solution prepared by mixing 35.0 mL of 0.375 M NaCl solution with 47.5 mL of a 0.632 M NaCl solution?
IV) Acetic acid, CH3COOH, reacts with ethanol, CH3CH2OH, to form ethyl acetate, CH3COOCH2CH3, (density 0.902
g/mL) by the following reaction:
CH3COOH + CH3CH2OH CH3COOCH2CH3 + H2O
We combine 20.2 mL of acetic acid with 20.1 mL of ethanol.
(a) Which compound is the limiting reactant?
(b) If 27.5 mL of pure ethyl acetate is produced, what is the percent yield? [Hint: See Tables 1-2 and 1-9.]
V) The label on a bottle of concentrated ammonia says that the contents are 28.0% (by mass) NH3 and have a density of 0.898 g/mL. What is the
molarity of the concentrated ammonia?
AP Review Chp 4 Mon 10/7/2013
I) Magnesium oxide, marketed as tablets or as an aqueous slurry called “milk of magnesia,” is a common commercial antacid. What volume, in
milliliters, of fresh gastric juice, corresponding in acidity to 0.17 M HCl, could be neutralized by 104 mg of magnesium oxide?
II) Predict whether or not a solid is formed when we mix the following; identify any solid product by name and identify the reaction type:
(a) copper (II) nitrate solution and magnesium metal,
(b) barium nitrate and sodium phosphate solutions,
(c) calcium acetate solution with aluminum metal,
(d) silver nitrate and sodium iodide solutions.
III) Write total net ionic equations for the following unbalanced redox reactions occurring in aqueous solution or in contact with water. Identify the
species being oxidized and reduced in each reaction.
(a) H2(g) + Al2O3(s) Al(s) + H2O(l)
(b) Zn(s) + CoCl3(aq)  ZnCl2(aq) + Co(s)
(c) H2S + HNO3 H2SO4 + NO2(g) + H2O(l)