In which of the following values of kc,the reaction goes to completion in the forward direction;
Refer to the problem above where kc = unity. If the reaction goes to completion then P will be very large and R will be very small so that K is a large number. Think about it this way.
If P is 2 and R is 1, then K = 2/1 = 2 and that means products are twice reactants. That is a forward reaction but not all that forward.
If P is 1,000.000 and R is 0.000,001 then K = 1E6/1E-6 = 1E12 and that is a reaction that has gone far to the right or very near completion.
What following?
To determine the values of Kc at which a reaction goes to completion in the forward direction, we need to understand the concept of reaction quotient (Qc) and the relationship between Qc and Kc.
The reaction quotient, Qc, is calculated using the same formula as Kc, but it is calculated at any given point during a reaction rather than at equilibrium. Qc helps compare the ratio of product and reactant concentrations at a specific point in time to the equilibrium ratio described by Kc.
If Qc is smaller than Kc, it means that there are fewer products than at equilibrium, and the reaction will proceed in the forward direction to reach equilibrium. If Qc is larger than Kc, it means there are more products than at equilibrium, and the reaction will proceed in the reverse direction to reach equilibrium. Lastly, if Qc is equal to Kc, it means the reaction is at equilibrium and will not proceed in either direction.
So, if we want the reaction to go to completion in the forward direction, we need to consider values of Kc where the reaction quotient, Qc, is much smaller than Kc. This indicates that initially, there are significantly fewer products than the equilibrium concentration, prompting the reaction to proceed forward until equilibrium is reached.
Without specific values for Kc options or the reaction equation, I cannot provide an exact answer. However, you can calculate the reaction quotient (Qc) for each given value of Kc and determine which value of Kc has the smallest Qc. That would indicate the value at which the reaction goes to completion in the forward direction.
Here's an example of how you can calculate the reaction quotient (Qc) using an equation:
1. Write the chemical equation for the reaction.
2. Determine the stoichiometric coefficients of the reactants and products.
3. Assign variables (x, y, z, etc.) to represent the molar concentrations of the species involved.
4. Write the expression for Qc using the given variables and stoichiometric coefficients.
5. Substitute the known concentrations into the Qc expression and calculate the value.
By comparing the calculated values of Qc to the given values of Kc, you can identify the value of Kc at which the reaction goes to completion in the forward direction.