Chemistry Final Review

Unit 1

100

Which of the following include all intensive properties? a) mass, density, color b) volume, boiling point, hardness c) boiling point, density, color d) length, temperature, hardness

C- Intensive properties are independent of the amount of substance

200

PERC (C2Cl4) vapors often escape to the atmosphere. The current permissible exposure limit for this substance is in air is an average of 100 ppmv in an 8-hr period. Express this concentration in mg/m^3. (assume STP conditions). 1 m^3=1000 L

740 mg/m^3

300

How would the kinetic energy and potential energy of a molecule change as it changes from gas to liquid?

The average kinetic energy of the molecules increases as T increases until the phase change point. At that point the average KE remains constant until the phase change is complete. Further heating then increases the average KE of the liquid. The potential energy of the gas decreases as the gas is pressurized due to the molecules being on average closer together, and continues to decreases throughout the phase change from gas to liquid. The PE should change a little bit (lower) upon further pressurization of the liquid but not as much as the change in the pressurization of the gas.

400

http://www.cem.msu.edu/~mantica/cem152/prep2/syrupvp.html Using the liquid gas transition line estimate the temperature at which this substance will boil at 3 atm of pressure.

135 degrees Celsius

500

Combustion analysis reveals that the substance contains 12.79% C, 2.14% H, and 85.07% Br. (Molar mass according to mass spec is about 188 g/mol) a) What is the empirical formula? b) What is the molecular formula?

a) CH2Br b) C2H4Br2

Unit 2

100

http://www2.lbl.gov/MicroWorlds/ALSTool/EMSpec/ a) Which of these has a higher frequency a or b? b) Which of these has a higher energy a or b?

a) B- wavelength and frequency are inversely proportional b) B- wavelength and energy are also inversely proportional

200

Draw the molecular structure for C2H7N ( bonds: N-H, C-H, C-C, and C-N)

https://www.google.com/search?q=molecular+structure+for+C2H7N&espv=2&biw=1158&bih=541&source=lnms&tbm=isch&sa=X&ei=3caJVNH_JYSoyQTK74LICg&ved=0CAYQ_AUoAQ#facrc=_&imgdii=_&imgrc=AnBgw79EIfj9DM%253A%3BPEwasjJTfc1oYM%3Bhttp%253A%252F%252Fwww.worldofchemicals.com%252Fwoclite%252Ftmp%252Fchem%252Fp%252F0019cbc0-8e5e-11df-8bdb-3744afa52ae1_9611975ac96415125dcc22fb772b315a.png%3Bhttp%253A%252F%252Fwww.worldofchemicals.com%252Fchemicals%252Fchemical-properties%252Fethylamine.html%3B120%3B80

300

Predict the molecular shape and angle of: a) Methane (CH4) b) Carbon Dioxide (CO2) c) Carbonate ion (CaO3) 2- d) Sulfite ion (SO3) 2-

a) Tetrahedral, 109 degrees b) Linear, 180 degrees c) Trigonal Planar, 120 degrees d) Trigonal Pyramidal < 109 degrees

400

Build the electron configuration for: a) C b) Al c) Br

a) 1s^2 2s^2 2p^2 or [He] 2s^2 sp^2 b) 1s^2 2s^2 2p^6 3s^2 3p^1 or [Ne]3s^2 3p^1 c) 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^5 or [Ar] 4s^2 3d^10 4p^5

500

Draw the molecular structure for: a) Carbonyl b) Aldehyde c) Carboxyl d) Ether e) Amine f) Phenyl g) Hydroxyl

a) C double bonded to an O with two R on either side b) C double bonded to an O, single bonded to an H, and one R c) C double bonded to an O, then bonded to OH d) R-O-R e) N single bonded to three R f) diamond with C g) C-O-H

Unit 3

100

Strong intermolecular forces will result in which of the following (more than one answer): a) High boiling point b) High vapor pressure c) High surface tension d) High viscosity

a, c, d

200

Which of the following organic compounds is the least soluble in water? a) CH3CH2CH2COOH, butanoic acid b) CH3CH2CH2OH, 1-propanol c) CH3CH2CH2NH2, propyl amine d) C6H14, hexane e) C6H12O6, glucose

d because it has no polar functional groups.

300

Describe how the following will differ in boiling point, density, flexibility, and viscosity. a) Long, linear chain b) Short, branched chain

a) Higher boiling point, higher density, not flexible, high viscosity. b) Low boiling point, low density, flexible, low viscosity

400

a) What is the chemical formula for the compound formed between iron(III) and chlorine? b) What is the chemical formula for the compound formed between iron(III) and selenium?

a) FeCl3 b) Fe2Se3

500

Rank these compounds in order of increasing lattice energy. a) KBr b) KI c) KF d) KCl Rank these compounds in order of increasing melting point: a) SrF2 b) CsBr c) RbF d) SrO

KI, KBr, KCl, KI CsBr, RbF, SrF2, SrO

Unit 4

100

Write the balanced chemical equation for the reaction of zinc metal and hydrochloric acid produces hydrogen gas and zinc chloride.

Zn + 2HCl -----> H2 + ZnCl2

200

When heated, KClO3 decomposes into KCl and O2. a) Write the balanced chemical equation. b) If this reaction produced 50.8 g of KCl, how much O2 was produced (in grams)?

a) 2 KClO3-----> 2KCl + 3O2 b) 32.7 grams

300

Nitrogen and hydrogen combine at high temperature, in the presence of a catalyst, to produce ammonia. a) Write the balanced chemical equation b) Assume 0.230 mol of N2 and 0.749 mol of H2 are present initially.After complete reaction, how many moles of ammonia are produced? c) How many moles of H2 remain?

a) N2 + 3H2-----> 2NH3 b) .46 mol NH3 c) .059 mol H2

400

a) Write the balanced chemical equation for the decomposition of water vapor. b) Estimate the heat of reaction using bond energies. ( O-H: 464, H-H: 436, O=O: 498)

a) 2 H2O ----> 2 H2+ O2 b) 243 kJ/mol

500

a) Balance the following chemical equation: Co2 + H2 ----> CH3COOH + H2O b) Estimate the amount of energy generated per mole of acetic acid (CH3COOH) that is produced.(C=O (in CO2): 799, H-H: 436, C-H: 414, C-C: 347, C=O: 736, C-O: 360, O-H: 464

a) 2 CO2 + 4 H2-----> CH3COOH + 2 H2O b) -65 kJ/mol

Misc.

100

An open flask sitting in a lab fridge looks empty, but we know that actually it is filled with a mixture of gases called air. If the flask volume is 3.00 L, and the air is at standard temperature and pressure, how many gaseous molecules does the flask contain?

8.07 X 10^22 molecules

200

A certain shade of blue has a frequency of 7.18 × 1014 Hz. What is the energy of exactly one photon of this light?

4.76 X 10^-19

300

Calculate the energy for one mole of photons (an einstein) for light absorbed at 7.00 × 102 nm.

171000 J

400

There are two naturally occurring isotopes of rubidium. 85Rb has a mass of 84.9118 amu. 87Rb has a mass of 86.9092 amu. Determine the abundance of each isotope.

85Rb= 72.06% 87Rb= 27.94%

500

Select the correct value for the indicated bond angle in each of the following compounds: a) O-O-O angle of O3 b) O-S-O angle of SO3 c) Cl-S-Cl angle of SCl2 d) Cl-S-O angle of SOCl2 e) H-C-H angle of CH4

a) < 120 degrees b) 120 degrees c) < 109 degrees d) < 109 degrees e) 109 degrees