Name:  _____________________                              date:  __________________               period: _______

 Ch. 2, 5, 11   conversion factor / density, light, mole / empirical formula                  50 points          honors chemistry

In problems involving any calculation, show your work in an organized manner, include (i) any relevant equation (or formula), (ii) conversion factor(s), (iii) put the proper units in your calculations and answer, and (iv) have the proper number of significant figures in your answer.

1. A carboxylic acid, which contains carbon, hydrogen, and oxygen, has a molar mass of 88 g / mole.  The complete combustion of 1.0 g of the carboxylic acid generates 2.00 g of carbon dioxide and 0.818 g of water.  What is the chemical formula of the carboxylic acid ?  [weekly quiz question; 15 points]


2. Light:  pick one problem.  Clearly identify the problem chosen; no extra credit for doing both problem; if you do both problems, will score the second choice.  [15 points]

3. A hypothetical metal has a minimum frequency of 5.56 * 10 14 Hz for the photoelectric effect to occur.  An incident light with a wavelength of 500.0 nm is shone onto the metal.  What is the kinetic energy of the emitted electron ?  [weekly quiz question]

4. Based on the phet simulation, a hypothetical atoms has 3 different electron energy levels.  Sketch / label these electron energy levels and its corresponding emission spectrum with all possible signals and identify the electron energy level transition for each signal in its spectrum.

5.  Solve.  [20 points]

a.  275 cm 2 / second  =  ___  m 2 / minute

b. 275 mmoles of calcium phosphate =  __ g calcium phosphate

c. A rectangular solid with dimensions of 5.0 cm x 2.0 cm x 16.0 cm has a density of 8.0 g / mL; what is its volume?

d. 25.0 g of sodium sulfate  =  __ moles of sodium sulfate