Q2A: Calculate the Equilibrium constant (Kea) for the following reaction: N2(g)+3H2(g)= 2NH;(g) When the equilibrium concentrations were found to be:[N2]=0.06 M ,[H2]=0.04 M and [NH3]=0.32 M . B: What are factors affecting on chemical equilibrium?

During an experiment with the Haber process, a researcher put 1 mol N2 and 1 mol H2 into a reaction vessel to observe the equilibrium formation of ammonia, NH3. N2(g)+3H2(g)2NH3(g) When these reactants come to equilibrium, assume that x mol H2 react. How many moles of ammonia form?

In Section 17.3 of your text, it is mentioned that equilibrium is reached in a closed system. What is meant by the term “closed system,” and why is it necessary for a system to reach equilibrium? Explain why equilibrium is not reached in an open system.

12.100 A reaction important in smog formation is O3(g)+NO(g)O2(g)+NO2(g)K=6.01034 (a) If the initial concentrations are [O3]=1.0106M,[NO]=1.0105M,[NO2]=2.5104M, and [O2]=8.2103M , is the system at equilibrium? If not, in which direction does the reaction proceed? (b) If the temperature is increased, as on a very warm day, will the concentrations of the products increase or decrease? (HINT: You may have to calculate the enthalpy change for the reaction to find out if it is exothermic or endothermic.)

Suppose a reaction has the equilibrium constant K = 1.3 108. What does the magnitude of this constant tell you about the relative concentrations of products and reactants that will be present once equilibrium is reached? Is this reaction likely to be a good source of the products?

12.108 A nuclear engineer is considering the effect of discharging waste heat from a power plant into a lake and estimates that this may warm the water locally to 25 °C. One question to be considered is the effect of this temperature change on the uptake of CO2 by the water. The equilibrium constant for the reaction CO2+H2OH2CO3 ; is K=1.7103 at 25 °C. Because bonds form, the reaction is exothermic. (a) Will this reaction progress further toward products at higher temperatures near the water discharge with its warmer water than it would in the cooler lake water? Explain your reasoning. (b) Carbonic acid has a Kaof 2.5104 at 25 °C. What is the equilibrium constant for the CO2+2H2OHCO3+H3O+? (c) What additional factor should the engineer be considering about CO2 gas, probably before considering this reaction chemistry?

When a mixture of hydrogen and bromine is maintained at normal atmospheric pressure and heated above 200. °C in a closed container, the hydrogen and bromine react to form hydrogen bromide and a gas-phase equilibrium is established. Write a balanced chemical equation for the equilibrium reaction. Use bond enthalpies from Table 6.2 ( Sec. 6-6b) to estimate the enthalpy change for the reaction. Based on your answers to parts (a) and (b), which is more important in determining the position of this equilibrium, the entropy effect or the energy effect? In which direction will the equilibrium shift as the temperature increases above 200. °C? Explain. Suppose that the pressure were increased to triple its initial value. In which direction would the equilibrium shift? Why is the equilibrium not established at room temperature?

Consider the system 4 NH3(g) + 3 O2(g) ⇌ 2 N2(g) + 6 H20(ℓ) ΔrH° = −1530.4 kJ/mol How will the amount of ammonia at equilibrium be affected by removing O2(g) without changing the total gas volume? adding N2(g) without changing the total gas volume? adding water without changing the total gas volume? expanding the container? increasing the temperature? Which of these changes (i to v) increases the value of K? Which decreases it?

12.101 An engineer working on a design to extract petroleum from a deep thermal reservoir wishes to capture toxic hydrogen sulfide gases present by reaction with aqueous iron(II) nitrate to form solid iron(II) sulfide. (a) Write the chemical equation for this process, assuming that it reaches equilibrium. (b) What is the equilibrium constant expression for this system? (c) How can the process be manipulated so that it does not reach equilibrium, allowing the continuous removal of hydrogen sulfide?

How does equilibrium represent the balancing of opposing processes? Give an example of an “equilibrium” encountered in everyday life, showing how the processes involved oppose each other.