Chapter One Chemical Foundations

Document Sample
Chapter One Chemical Foundations Powered By Docstoc
					General instructions: all math problems require work – complete
setups labeled with units and attention paid to significant figures!

                         Chapter One: Chemical Foundations
1.         An ancient cylindrical gold coin is 2.2 cm in diameter and 3.0 mm thick. If the density of
           gold is 19.3 g/cm3, what is the mass of the coin in grams? Assuming the price of gold is
           $410 per troy ounce, how much is the gold in the coin worth? (1 troy ounce = 31.10
           grams)


2.         The density of a solution of sulfuric acid is 1.285 g/cm3 and it is 38.08% (by weight)
           acid. How many milliliter of the acid solution do you need to supply 125 grams of
           sulfuric acid?


3.         Copper has a density of 8.94 g/cm3. If a factory has an ingot of copper with a mass of
           125 pounds and the ingot is drawn into a wire with a diameter of 9.50 mm, how many
           feet of wire can be produced? (454 grams = 1 pound)




                     Chapter Two: Atoms, Molecules, and Ions
Complete the following chart:

     Symbol              # protons         # neutrons         # electrons       Net charge
      238
      92
            U
                             20                20                                    2+
                             23                28                 20
      89
       39
           Y
                             35                44                 36
                             15                16                                    3-
Refresh your chemical nomenclature. When a formula has been given, write the name.
When the name has been given, write a balanced formula.

                                        Binary Compounds

Metal and Nonmetal – a salt
NaBr _____________________________                CdS      _____________________________
Zn3N2 _____________________________               SrCl2 _____________________________
CuCl _____________________________                Ag2O _____________________________
AlI3    _____________________________             FeO      _____________________________
Magnesium phosphide            ___________        potassium nitride            ___________
Lead(IV) sulfide               ___________        nickel(III) chloride         ___________

Two Nonmetals
SiO2    _____________________________             BF3      _____________________________
N2O5 _____________________________                AsBr5 _____________________________
Sulfur hexafluoride            ___________        tetraphosphorus heptoxide    ___________
Carbon tetrachloride           ___________        diphosphorus pentoxide       ___________

Binary Acids – you’ll get to these in a bit

                                       Ternary Compounds

Metal Cation (or ammonium) and a Polyatomic Ion
K2SO4            ___________________________      Ag2CrO4____________________________
Ca(OH)2          ___________________________      Zn(ClO3)2___________________________
Al2(S2O3)3       ___________________________      Cu2CO3 ____________________________
Sn(SCN)4         ___________________________      Li3PO4 _____________________________
KMnO4            ___________________________      NaClO______________________________
magnesium dichromate           _______________    ammonium carbonate __________________
barium oxalate                 _______________    lead(II) nitrite       __________________
zinc phosphate                 _______________    tin(II) cyanide        __________________
cobalt(III) sulfite            _______________    aluminum acetate       __________________

Oxyacids – see next section
                     Acids are named based on their anion ending
   -IC FROM –ATE
                    -OUS FROM –ITE
                                                 HYDRO-, -IC , -IDE




 Name of Acid              Formula of Acid                         Name of Anion

hydrochloric acid                       HCl                           chloride

  sulfuric acid                       H2SO4                            sulfate

                                          HI

                                                                       sulfite

  chlorous acid

                                                                       nitrate

                                   HC2H3O2

hydrobromic acid

                                                                       sulfide

                                      HNO2

  chromic acid

                                                                      phosphate
       Chapter Three: Stoichiometry
Write, complete and balance equations for the following reactions:

1.     Diphosphorus trioxide is formed from the direct combination of its elements.


2.     Aluminum replaces hydrogen when the metal is placed in hydrochloric acid.


3.     Barium hydroxide solution is neutralized with sulfuric acid.


4.     Propane, C3H8, burns in air to produce carbon dioxide and water.


5.     Ammonium nitrate may be decomposed into nitrogen and water.


6.     Barium carbonate precipitates when solutions of barium chloride and ammonium carbonate are
       combined.


7.     Ammonium sulfate is the only product of the reaction between ammonia (NH3) and sulfuric acid.


8.     Potassium chlorate decomposes into potassium chloride and oxygen.


9.     Zinc replaces lead when it reacts with lead(II) nitrate solution.


10.    Lithium oxide reacts with water to form lithium hydroxide solution.


11.    Carbon dioxide and water are two of the three products of a reaction between magnesium
       carbonate and hydrochloric acid.


12.    Carbon disulfide is oxidized to produce both carbon dioxide and sulfur dioxide.


13.    Butanal, C3H7CHO, is burned completely in air.
1.   Magnesium is commonly extracted from seawater. Magnesium-24 is its most abundant isotope
     (78.70%); its exact mass is 23.985 amu. If the atomic weight of magnesium is 24.305 amu, what
     are the relative abundances of magnesium-25 (mass of 24.986 amu) and magnesium-26 (mass of
     25.983 amu)?

2.   The Statue of Liberty is made up of 2.00 X 105 pounds of copper sheets bolted to an iron
     framework. How many atoms of copper make up the fair lady of the New York harbor?

3.   Monosodium glutamate, MSG, is a common food additive that serves as a flavor enhancer. Its
     formula is HOOCCH2CH2CH(NH2)COONa.
     (a) Calculate the molar mass of MSG.
     (b) How many moles are there in 2.00 g (about 1 teaspoonful) of MSG?
     (c) How many atoms of O are there in 2.00 g (about 1 teaspoonful) of MSG?

4.   The most common beryllium-containing mineral is beryl, which occurs mostly as large blue-
     green crystals with the formula Be3Al2(SiO3)6.
     (a) What is the molar mass of beryl?
     (b) How many moles are there in a 0.25 g crystal?
     (c) How many grams of beryl must you have in order to have 10. g of beryllium?

5.   A major oil company has used a gasoline additive called MMT to boost the octane rating of its
     gasoline. What is the empirical formula of MMT if it is 49.6% C, 3.20% H, 22.0% O, and
     25.2% Mn?

6.   Vanillin is a common flavoring agent. It has a molar mass of 152 g/mol and is 63.15% carbon,
     and 5.20 % hydrogen. The remainder is oxygen. Determine the molecular formula of vanillin.

7.   Over the years the thermite reaction has been used for welding railroad rails, in incendiary
     bombs, and to ignite solid fuel rocket motors. The reaction is
                    Fe 2 O 3 (s)  2Al(s)  2Fe(l)  Al 2 O 3 (s)
     (a) What masses of iron(III) oxide and aluminum must be used to produce 15.0 g iron?
     (b) What is the maximum mass of aluminum oxide that could be produced?

8.   Calculate the masses of Cr2O3, N2, and H2O produced from the decomposition of 10.8 g
     ammonium dichromate.

9.   Mercury and bromine will react with each other to produced mercury(II) bromide.
                             Hg(l)  Br2 (l)  HgBr 2 (s)
     (a) What mass of mercury(II) bromide can be produced from the reaction of 10.0 g Hg and 9.00
           g Br2? What mass of which reactant is left unreacted?
     (b) What mass of mercury(II) bromide can be produced from the reaction of 5.00 mL of mercury
           (density 13.6 g/mL) and 5.00 mL (density 3.10 g/mL)?