Which of the following statements is not true?
1.Chemical equilibria are examples of reversible processes.
2.When multiple reaction steps are in equilibrium, then the equilibrium constant for the net reaction is the product of the individual reactions.
3.The equilibrium constants are unitless (according to the book).
4. The value of Keq for the forward reaction equals 1-Keq for the reverse reaction.
#4 is not true; the others are true. I why #3 has that "according to the book". There are many posts I see and even a few texts that claim to show units for Keq, Ksp, Kc, Kp. etc. but in fact according to the book or not there are no units for these constants. The reason there are no units is because activities go there for concentrations and activities have no units. For #4, the correct statement is that the value of Keq for the forward reaction equals 1/keq for the reverse reaction.
To determine which of the statements is not true, we can individually analyze each statement:
1. Chemical equilibria are examples of reversible processes: This statement is true. Chemical equilibria occur when the rates of the forward and reverse reactions are equal, indicating a reversible process.
2. When multiple reaction steps are in equilibrium, then the equilibrium constant for the net reaction is the product of the individual reactions: This statement is not true. When multiple reaction steps are in equilibrium, the equilibrium constant for the net reaction is the ratio of the rate constants of the forward and reverse reactions for the overall balanced equation.
3. The equilibrium constants are unitless (according to the book): This statement is true. Equilibrium constants are ratio constants and do not possess any units. They are determined by using the concentration of the reactants and products, and their units cancel out during the calculation.
4. The value of Keq for the forward reaction equals 1-Keq for the reverse reaction: This statement is not true. The equilibrium constant (Keq) for the forward reaction is not equal to 1 minus the equilibrium constant for the reverse reaction. Keq values for the forward and reverse reactions represent the ratio of the products to reactants at equilibrium under specific conditions of temperature and pressure.
Therefore, statement 2 is not true as the equilibrium constant for the net reaction is not the product of the individual reactions.