Problem 17 What happens to a chemical syste... [FREE SOLUTION] (2024)

FAQs

What will happen if a chemical reaction system is stressed by an increase in the concentration of reactants? ›

For example when the reactant concentration is increased, the equilibrium will shift in the forward direction so that more and more reactants will react. This will decrease the reactant concentration.

The standard free energy change (∆Gº') of a chemical reaction is the amount of energy released in the conversion of reactants to products under standard conditions.

Adding or Removing a Product or Reactant

If more A is added, the reaction will shift to the right to restore the equilibrium ratio. Adding B will shift the reaction left. Removing A shifts the reaction left; removing B shifts it right.

What can be said about a chemical system that has reached a minimum in free energy? The system has achieved equilibrium.

When you alter something in a reaction at equilibrium, chemists say that you put stress on the equilibrium. When this occurs, the reaction will no longer be in equilibrium and the reaction itself will begin changing the concentrations of reactants and products until the reaction comes to a new position of equilibrium.

Increasing the concentration of one or more reactants will often increase the rate of reaction. This occurs because a higher concentration of a reactant will lead to more collisions of that reactant in a specific time period.

Gibbs free energy, denoted G, combines enthalpy and entropy into a single value. The change in free energy, ΔG, is equal to the sum of the enthalpy plus the product of the temperature and entropy of the system.

Reactions that have a negative change in free energy and consequently release free energy are called exergonic reactions. Think: exergonic means energy is exiting the system. These reactions are also referred to as spontaneous reactions, and their products have less stored energy than the reactants.

Conclusions: The rate and direction of a chemical reaction depends on the free energy, entropy, and concentration of the reactants and products as well as the temperature and pH of the system. Chemical reactions progress in the direction of high to low energy.

Chemical reactions involve breaking chemical bonds between reactant molecules (particles) and forming new bonds between atoms in product particles (molecules). The number of atoms before and after the chemical change is the same but the number of molecules will change.

What happens when you remove reactions from a system? ›

Re: removing a reactant

When you remove a reactant, the reaction will shift to the left to bring the system back to equilibrium by replacing the reactant that was removed.

Chemical reactions that absorb (or use) energy are called endothermic. In endothermic reactions, more energy is absorbed when the bonds in the reactants are broken than is released when new bonds are formed in the products.

As per the laws of thermodynamics, when the free energy content of products is less than the free energy content of substrates, the process occurs spontaneously. Thus free energy of system decreases in a spontaneous process.

The change in Gibbs free energy (ΔG) equals zero when a system is at equilibrium. At equilibrium, the system has reached a state of balance where the forward and reverse reactions occur at the same rate, and there is no net change in the concentrations of reactants and products over time.

This is because some mixing always lowers the free energy (increased mixing leads to higher entropy leading to lower free energy). So the equilibrium point is always somewhere in between these two extremes.

If the concentration of reactants is increased, there are more reactant particles moving together. There will be more collisions and so the reaction rate is increased. The higher the concentration of reactants, the faster the rate of a reaction will be.

In the given equation, the concentration of the product is increased. The system will readjust itself to decrease the product concentration. A backward reaction will be favored. Hence, the new equilibrium mixture will contain a higher concentration of the reactant.

Increasing the concentration of the reactants will increase the frequency of collisions between the two reactants. When collisions occur, they do not always result in a reaction (atoms misaligned or insufficient energy, etc.). Higher concentrations mean more collisions and more opportunities for reaction.

Increasing the concentration of one or more of the reacting substances generally increases the reaction rate. When more particles are present in a given amount of space, a greater number of collisions will naturally occur between those particles.