[dellanebbia]

1. The first step in industrial nitric acid production is the catalyzed oxidation of ammonia. Without a catalyst, a different reaction predominates:

4NH3(g) + 3O2(g) ⇔ 2N2(g) + 6H2O(g)

When 0.0210 mol NH3(g) and 0.0150 mol O2(g) are placed in a 1.00 L container at a certain temperature, the N2 concentration at equilibrium is 2.90×10-3 M. Calculate Keq for the reaction at this temperature.

2. If the equilibrium constant for the reaction:

2HCl(g) <==> H2(g) + Cl2(g)

is 6.8x10-54 at 25oC, calculate the concentration of hydrogen gas in equilibrium with 0.012 mol of HCl in a 1.00-L container, assuming that only HCl was present originally.

3. At a particular temperature assume that the equilibrium constant for the reaction:

H2(g) + F2(g) <==> 2HF(g)

is K = 100.0. A reaction mixture is prepared in a 1.000 liter flask with 2.7 moles each of hydrogen and fluorine gas plus for some unexplained reason 4.7 moles of HF. What is the equilibrium concentration of hydrogen from this initial mixture?

4. The rate constant for a certain chemical reaction is 98.0 s-1 at a temperature of 20.0°C. If the activation energy for this reaction is 52. kJ/mole, what is the rate constant at a temperature of 30.0°C?

5. A certain batch of fireflies were observed to "flash" at the rate of 12.4 times per minute at 25°C and at the lower rate of 5.1 times a minute at a temperature of 15°C. Assume that the flashing is the result of an overall chemical reaction that has a single rate limiting step with the highest activation energy. Use this data to estimate the activation energy for this slowest step. You can assume that the concentrations of "reactants" in the fireflies do not depend on temperature.

[Astrokel]

You have to show some attempts so we know where you have went wrong.