Name ______

Chemistry 103: General Chemistry I

FinalExamination

December 11, 2007

Instructions:

  1. Relax. An equation sheetand a Periodic Table are provided.
  2. Boxthe answers to calculations.Be sure to have the correct sig. figs and units!
  3. Be sure to keep the proper units during your calculations and show all work for full credit.
  4. Good Luck!!!!!!!!!!

Part 1: New material

  1. (9 pts.)

a) Assume the hydrogen filled balloon used by Charles in his historic flight over Paris in 1783 was filled with 4.20 x 104 L of H2 (g). Let’s assume that the temperature that day was 18.0 C and the pressure was 700.0 mm Hg. How many moles of hydrogen gas filled the balloon? Start by writing the equation needed to solve the problem.

b) How many molecules of H2 would this have been?

  1. (6 pts.) Assuming that the initial pressure was 700.0 mmHg, and the temperature was 18.0 °C, let’s assume that when the 4.20 x 104 L balloon in question 1 went up to 3,000 ft. the temperature was -42.0 C and the pressure was 0.25 atm. What was the volume of the balloon at 3,000 ft.? Start by writing the equation needed to solve the problem.
  1. (10 pts.) Assume you are a chemist working to develop automobile air bags. The decomposition reaction to produce N2 is below:

2NaN3 (s)  2 Na (s) + 3 N2 (g)

Calculate the volume of nitrogen generated at 70.0oC and 456.0 mm Hg (Pike’s peak) bythe decomposition of 35.0 g of NaN3 (MM= 65.02 g/mol).

  1. (2 pts.) Which compound has the strongestintermolecular forces?
  1. C6H14b. CH3OH
  1. C2H4d. SF4
  1. (2pts.) Which compound is the least likely to be miscible or soluble in water?

a. HClc. KNO3

b. NH3d. CCl4

  1. (4 pts.) Which has the highest boiling point? Circle correct answer for each pair.

CH3-CH2-CH3 or CH4CH2=O or CH3OH

CH4 or NH3F2 or I2

  1. (12 pts.) The density of thallium chloride is 7.00 g/cm3. It has a cell edge of 385.0 pm. Does TlCl (FW=239.83 g/mol) have a fcc unit cell geometry? Demonstrate through calculation if this is the correct geometryand answer Yes or NO (circle).

Is this the correct geometry? Yes or no (circle the correct answer)

  1. (10 pts.)

a)Draw the phase diagram for water. Label regions solid, liquid or gas.Label the freezing and boiling points at 1 atm.

b)Explain in terms of intermolecular forces why water boils at 100 C whereas carbon dioxide sublimes at room temperature.

  1. (12 pts.) Assume concentrated HCl (molar mass 36.46 g/mol) is37.0% by weight and its density is 1.19 g/mL. What is the molar concentration of concentrated HCl?
  1. (21pts.)

a)A protein (not ionized) obtained from crabs is hemocyanin. If you prepared a solution of 7.50 g hemocyanin in 0.400 L of water, the solution has an osmotic pressure of 0.00562 atm at 298.0 K. What is the molar mass of hemocyanin? Start by writing the equation needed to solve the problem.

b)Assuming the molality of the solution is 2.30 x 10-4 m and Kf = 1.86 C/m for water, what is the freezing point of the solution?

  1. (12 pts.)

a)Assume you have 434.0 g of ethylene glycol (MW= 62.07 g/mol) dissolved in 2.59 Kg of water (MW=18.02 g/mol) at 26.0 C, what is the PH2Oin atmif PH2O=525.8 mm Hg at 26.0C? Start by writing the equation needed to solve the problem.

b)Comparing this value to the partial pressure of pure water, what is the change in vapor pressure?

Part 2: Comprehensive.

  1. (3 pts.) Write the formula for the ionic compounds that form between the following.

the potassium ion and the nitrate ion ______

the aluminum ion and the chloride ion ______

copper (II) perchlorate ______

  1. (6 pts.) Write the formulaor name the following compounds:

potassium dichromate ______barium carbonate ______

KOH ______Ca(NO3)2 ______

N2O ______sulfur dioxide ______

  1. (13 pts) You think that you have extracted glucose from a blood sample in the lab. Using mass spectrometry you determine that this unknown compound is 40.0 % carbon, 6.72% hydrogen, and 53.3% oxygen. Determine the empirical formula of the unknown compound.
  1. (5 pts.) The wavelength of the radio station KRCC is 3.28 m. What is the frequency of the broadcast (in MHZ if 1 MHz= 106 Hz)? Start by writing the equation needed.
  1. (5 pts.) Many buildings in some parts of the country are built using rock chalk, or CaCO3. Acid rain is acidic somewhat like HCl. If you add these two together you get the following reaction:

CaCO3 (s) + 2 HCl (aq)  CaCl2 (aq) + H2O (l) + CO2 (g)

How many grams of CaCO3 (FW= 100.09 g/mol) will react with 14.00 mL of 0.600 M HCl?

  1. (2 pts.) Circle the species in each pair with the largerfirst ionization energy:

Br or CaAl or Cl

  1. (2 pts) We are learning about ionization energy because…

a)It allows us to predict which species will be cations and which may be anions, and therefore chemical reactions

b)It allows us to calculate energies of reactions

c)It allows us to determine volumes of gases

d)It allows us to determine which species will be transition metals

  1. (5 pts.) How much heat (in kJ) does it take to raise the temperature of 344.0 g of water from room temperature (22.0 C) to boiling (100.0 C)? Assume that the specific heat of water is 4.18 J/g C. Start by writing the equation that you’ll need to solve the problem.
  1. (4 pts.)Testosterone is a steroid hormone (C19H28O2, molar mass 288.42 g/mol ). You want to prepare a 250.0 mL solution of 24.0 mM testosterone for use in the hospital.

a)Calculate how much testosterone (in grams) that you need to weigh out.

  1. (5 pts) Let’s say that you need a 10.0 mM solution of testosterone. How much of the 24.0 mM solution do you need to make 10.00 mL of this solution?
  1. (12 pts.) Write the spectroscopic notation for the electron configurations of the following. Include the noble gas configuration in brackets.

Fe2+ ______Cu ______

B ______C ______

Which of the above is/are paramagnetic?

  1. (17 pts.) Write the following reactions between aqueous barium chloride and aqueous sodium sulfate. Be sure to write the state for each species for full credit.

Molecular Equation:

Ionic Equation:

Net Ionic Equation:

  1. (12 pts.) Draw the most stable Lewis structures for the following compounds in the correct geometry.

AmmoniaHCO2 – (the formate ion)

Sulfur tetrafluorideXeF4

WaterXeF2

  1. (4 pts) Which of the species in the previous question is/are not polar?
  1. (6 pts) Determine the molecular geometry of the following compounds

PF5SO42-BCl3

Formulas:

Psolvent = Xsolvent PsolventTb = iKb mTf =iKf mTb = Tb- Tb

= cRT Tf = Tf - TfC=kP

R= 0.0821 L atm/mol KE= h where h= 6.63 x 10-34 Js

1/= R [1/n12-1/n22] where R= 1.097 x 107 m-1 E= - RH/n2 where RH= 2.18 x 10-18 J

b.o= (# shared pairs in x/y link)/ # x-y links

b.o.= ½ (#e- in bonding m.o. – # e- in antibonding m.o.) C=3.00 x 108 m/s = 

E= RH (1/ni2-1/nf2)1 km= 1000 meters1 kilogram = 1000 grams

H°rxn = Σ D(bonds broken)-Σ D(bonds formed)M1V1=M2V2

oF= (9 oF/ 5 oC) oC + 32 oFK= oC + 273.15q= mCT

oC= (5 oC/ 9 oF) (oF-32 oF)H=qp

Formal charge= # valence electrons – [# nonbonding e- + ½ # bonding e-]

H°rxn = Σ n H° f (Products)-Σ m H° f (Reactants)M1V1=M2V2

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