1) Calculate the frequency, in s-1, of light with a wavelength of 650nm. 

2) How much energy is released from a hydrogen atom when an electron moves from ni = 4 to nf = 2?  Where RH is the Rydberg constant, 2.18 x 10-18 J, n represents the principal quantum number, and the subscripts i and f, represent the initial and final states. 

3) 4.98 g of copper is produced when 2.92 g of Al are reacted with excess copper (II) sulfate.

2Al + 3CuSO4 Al2(SO4)3 + 3Cu    5pts.  Ea.

A) What is the theoretical yield?

B) What is the actual yield?

C) What is the Percent yield?

4) What mass of CO2 could be formed by the reaction of 15.0g of CH4 with 38.0g of O2.  This is the balanced equation CH4 +2O2 →CO2 + 2H2O. 5pts.  Ea.

A) Find mass of CO2 produced

B) Find mass of excess reactant left unreacted

5) How many liter of CO2 at STP will be produced from the complete combustion of 23.2g C2H6:

A) Find the balance combustion reaction equation.

B) Find the liters of CO2 produced at STP.

C) Find the liters of O2 required.

6) How many milliliters of 1.0 M NaOH are needed to make 100ml of 0.4M NaOH.

7) If 3.0ml of distilled water is added to 2.0 ml of 0.35M CoCl2 solution, what is the concentration of the resulting solution? 5pts.

8) How would you prepare 1 liter of 0.4M NaOH from solid NaOH. (GMW 40 gmol) 10pts

9) Find the percent composition of N2O3.

10) How many moles of helium gas, He, are contained in a balloon that has a volume of 12.8 liters?

11) If 12.1g of Fe are added to a solution of Copper(II) Sulfate, how much solid copper would form.   2Fe + 3CuSO4 →Fe2(SO4)3 + 3Cu

12) If 3.0ml of distilled H2O is added to 2.0ml of 0.35M CoCl2 solution. What is the concentration of the resulting solution?

13) Find the empirical formula for a compound consisting of 81.7% C and 18.3% H.