# chemistry

What is the pressure change for the reaction below at 25 C in the process of reaching equilibrium if there is initially enough ammonium hydrogen sulfide to reach equilibrium?

Kp= 4.0*(10^4)

NH3(g)+H2S(g) ---><--- NH4HS(s)

Answer: 1.0*[10(-2)]

Not sure what to do here; I know the the Qc expression is:

Qc= 1/([NH3][H2S])

and Kp=Kc[(RT)^(delta n)]

but I'm not sure how to advance.

Is "delta n" -1 (1 mole product - 2 mole reactant)

OR

-2 (0 mole gaseous product - 2 mole gaseous reactant)

And how do I factor in the change? What is changing?

Thank you.

1. 👍 0
2. 👎 0
3. 👁 44
asked by l
1. Call pNH3 = p, then at equilibrium, partial pressure H2S must be p also, then
Kp = 4E4 = (1/pNH3*pH2S)
4E4 = (1/p2)
Solve for p which will give you partial pressure H2S and partial pressure NH3. Add them together to find the total pressure change. 1E-2 is the correct answer.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Chemistry

Which of the following is the best definition of Hess' Law? A. Since enthalpy is a state function, it will be different if a reaction takes place in one step or a series of steps. B. Heat is always released by the decomposition of

asked by Anonymous on February 24, 2008
2. ### Chemistry

Which of the following is the best definition of Hess' Law? A. Heat is always released by the decomposition of 1 mole of a compound into its constitute elements. B. The enthalpy of a process is the difference between the enthalpy

asked by Anonymous on February 20, 2008
3. ### Chemistry

Which of the following is the best definition of Hess' Law? A. Heat evolved in a given process can be expressed as the sum of the heats of several processes that, when added, yield the process of interest. B. The enthalpy of a

asked by Jared on May 7, 2007
4. ### Hess' law

Which of the following is the best definition of Hess' Law? A. Heat is always released by the decomposition of 1 mole of a compound into its constitute elements. B. Since enthalpy is a state function, it will be different if a

asked by christine on February 9, 2007
5. ### physical chemistry

I tried working out this problem but am unsure of a few steps. Please help me if you can. Consider O3 --->1.5O2 At 210degrees Celsius and an initial gas pressure of 0.23atm, it is found that the rate of reaction is 1.8E-2

asked by ajones on January 17, 2007
6. ### Chemistry

The reaction b/t H2 and O2 yield water vapor and has a change of heat =-484kJ.Ho much PV work is done and what is the value of the change of E in kJ for the reaction of 0.50 mol of H2 with 0.25 mol of O2 amd atmospheric pressure

asked by Angie on June 30, 2013
7. ### Chemistry

I need to calculate the mass of CO2 produced in the reaction of NaHCO3 + HCl Data Mass of NaHCO3 = .05g Mass of system before reaction 117.9 g Mass of system after reaction 117l98 Maxium pressure 1.4094 initial pressure 1.0094

asked by Sarah on June 24, 2014
8. ### Chemistry

A gaseous reaction occurs at a constant pressure of 50.0 atm and releases 69.8 kJ of heat. Before the reaction, the volume of the system was 8.80 L . After the reaction, the volume of the system was 2.80 L . Calculate the total

asked by Brittany on March 5, 2012
9. ### physics

A monoatomic ideal gas has Cp= 5R/2 a) four moles of the gas undergoes a process in which the temperature of the gas increases from 300 K to 500 K while the pressure is kept constant at 2.00 x 105 Pa. What is the change in the

asked by Julie on April 24, 2017
10. ### Physics

An ideal gas in a rigid container (constant volume) has its pressure cut in half slowly. In the process, 265 kJ of heat left the gas. (a) How much work was done during the process? (b) What was the change in internal energy of the

asked by Andrea on October 6, 2010
11. ### Chemistry

The oxidation of copper(I) oxide, Cu2O(s), to copper(II) oxide, CuO(s), is an exothermic process, 2 Cu2O + O2 --> 4CuO The change in enthalpy upon reaction of 75.30 g of Cu2O(s) is -76.83 kJ. Calculate the work, w, and energy

asked by chemgeek on November 4, 2013

More Similar Questions