Q4. A beta emission has a wavelength of 1,280 nm, what energy level (n) did the electron fall from?

Q5. The gamma Lyman emission of hydrogen corresponds to an electron dropping from which which energy level to which other energy level?

Q6. What is the wavelength of em radiation emitted from a n=4 to n=2 transition of hydrogen? What is the name of this transition?

1. A mixture containing 2.81 g each of CH4 (g), C2H4 (g) and C4H10 (g) is contained in a 1.50 L flask at a temperature of 35 oC. What is the partial pressure (in atm) of C4H10 (g)?

2. A sample of gas contains 62.0 moles at 327 K in 4.00 L of volume. What is the pressure (in atm) of the gas?

3. What is the molar mass of 572 mg of vapor in 0.500 L at 824 torr and 298 K?

A mixture of 6.92e-02 mol of Cl2, 2.15e-02 mol of H2O, 6.78e-02 mol of HCl, and 5.04e-02 mol of O2 is placed in a 1.0-L steel pressure vessel at 1447 K.

The following equilibrium is established: 2 Cl2(g) + 2 H2O(g) 4 HCl(g) + O2(g)

At equilibrium 1.43e-02 mol of H2O is found in the reaction mixture.

Calculate the equilibrium pressures of all gases in the reaction vessel and the value of KP for the reaction.

Pick the correct statement from the multiple choices.

Use the value R = 0.0821 L-atm/mol-K for the gas constant.

a) The equilibrium constant is KP = 2.7e-03 .

b) The equilibrium pressure of O2 is PO2 = 6.42 atm.

c) The equilibrium pressure of HCl is PHCl = 6.34 atm.

d) The equilibrium pressure of Cl2 is PCl2 = 9.07 atm.

e) The equilibrium constant is KP = 7.4e+01 .

At 25 ^oC a 0.50 g sample of polyisobutylene (a polymer used in synthetic rubber) in 100.0 mL of benzene solution has an osmotic pressure that supports a 5.1 mm column of solution (p = 0.88 g/mL). What is the molar mass of the polyisobutylene? (For Hg, p = 13.6 g/mL)

You want to prepare 450.0 mL of a 145 ppm K+ ion solution. The density of the solution is 1.01 g/mL. You have at your disposal a solution that is 0.728 M in K2SO4. How many mL of the K2SO4 solution do you need to use?

how many kj of heat are absorbed when 455g of water at 80.0C are heated to 100.0C and then completely evaporated at this tempertature? The Specific heat of water 4.184j/C, g and the molar heat of evaporation for water is 40.7kJ/mol.

A student ran the following reaction in the laboratory at 684 K: N2(g) + 3H2(g) 2NH3(g) When she introduced 3.26×10-2 moles of N2(g) and 6.07×10-2 moles of H2(g) into a 1.00 liter container, she found the equilibrium concentration of H2(g) to be 5.83×10-2 M. Calculate the equilibrium constant, Kc, she obtained for this reaction.

Kc = __

20 g of CaCl2 is added to a small amount of water in the flask. Additional water is added to bring the total volume of solution to 0.75 L.

(a) Calculate the concentration of calcium chloride in units of mg/L.

(b) Calculate the concentration of calcium chloride in units of Molarity.

(c) Calculate the concentration of calcium chloride in units of Normality.

(d) Calculate the concentration of calcium chloride in units of mg/L as CaCO3.

(e) 5 g of NaCl is added to the above CaCl2 solution. Calculate the total concentration (mg/L) of chloride in the solution.

Consider the following reaction: H2(g)+I2(g)⇌2HI(g) A reaction mixture in a 3.74 L flask at a certain temperature initially contains 0.767 g H2 and 96.8 g I2. At equilibrium, the flask contains 90.2 g HI.calculate the equillibrium constant (Kc) for the reaction at this temperature.

please show work

Briefly compare and contrast the S N 1 and S N 2 mechanisms in terms of kinetics, steric effect, nature of the nucleophile, and the nature of the leaving group.

 A wastewater contains 8 mg/L O2, 10-3 mol/L NO3 - , and 10-2 mol/L organic matter [CH2O] (no significant exchanges with atmosphere occur) After bacterial metabolism is complete, which of the following statements will be true? a) No [CH2O] remains b) Some O2 remains c) Some NO3 - remains d) Denitrification consumed more [CH2O] than respiration e) The composition of water remains unchanged

1) Offer a reasonable explanation of why nitration of 1,4-dichlorobenzene yields mononitro derivative while N,N'diacetyl- 1,4Phenylene- diamine forms dinnitro compound.

2) Explain why p- nitrophenol is a stronger acid than phenol itself. Would P-methoxyphenol be a stronger or weaker acid than phenol? Expain.

16. A solution is made by adding 0.500 mols of NaF and 0.500 mols of KCN to 0.75L of water. What will the pH of this solution be? You may need to refer to the Ka/Kb table attached to this exam for this problem. Give your answer to two decimal places.                   

Consider the formation of hydrogen fluoride:

H₂(g) + F₂(g) ↔ 2HF(g)

If a 3.8 L nickel reaction container (glass cannot be used because it reacts with HF) filled with 0.0054 M H₂ is connected to a 3.6 L container filled with 0.036 M F₂. The equilibrium constant, K_p, is 7.8 x 10¹⁴ (Hint, this is a very large number, what does that imply?) Calculate the molar concentration of HF at equilibrium.