Reference no: EM132418311

1. When a reaction contains a gas why is it important that the heat of the reaction is measured under constant pressure vs. constant volume conditions?
2. NH3(g) + HCl(g)--> NH4Cl(s) If you run the reaction starting with ammonia and hydrogen chloride in a 2.00 L closed container at a constant temperature of 298 K, would you expect the pressure in the container to increase, decrease, or stay unchanged as the reaction proceeds?
3. 6Li(s) +N2(g)-->2Li3N(s) What mass of Li is required to react with 18.7 L of N2 gas at 2.68 atm and 21.0 degrees C?
4. You have an unknown that is a mixture of NaCl and Na3PO4 solids. You add 10.0 grams of the unknown solid to 190.0 grams of 2.000M HCl solution with an initial temperature of 18.92 degrees C in a coffee cup calorimeter. Na3PO4(s) + 3 HCl(aq) --> 3 NaCl(aq) + H3PO4(aq) ?H = -499 kJ After the reaction is complete, you find the temperature in the cup to be 37.13 degrees C. What percent of the solid mixture is Na3PO4?
5. Light with a frequency (ν) = 2.37 x 1015 s-1 has sufficient energy to break the bond in N2. Calculate ?H (in kJ/mol) for the reaction: N2(g)--> 2N(g) ?H=?
6. Determine the energy, wavelength ,and frequency for the photon emitted when an electron in a hydrogen-like atom moves from an n= 6 to n = 3 level
7. In a single atom, how many electrons can have n=3 and l=2?
8. What is the quantum number that describes the energy of the electron in an H atom?