Reversible reactions
- Created by: emews
- Created on: 14-11-17 18:12
View mindmap
- Reversible reactions
- Many reactions, such as burning fuel, are irreversible - they go to completion and cannot be reversed easily.
- Reversible reactions are different. In a reversible reaction, the products can react to produce the original reactantsagain.
- When writing chemical equations for reversible reactions, the usual one-way arrow is not used. Instead, two arrows are used, each with just half an arrowhead - the top one pointing right, and the bottom one pointing left.
- The reaction between anhydrous copper(II) sulfate and water is used as a test for water. The white solid turns blue in the presence of water.
- Equilibrium
- If a chemical reaction happens in a container where one or more of the reactants or products can escape, you have an open system.
- If a chemical reaction happens in a container where none of the reactants or products can escape, you have a closed system.
- Reversible reactions that happen in a closed system eventually reach equilibrium.
- At equilibrium, the concentrations of reactants and products do not change. But the forward and reverse reactions have not stopped - they are still going on, and at the same rate as each other.
- You can predict what happens to the amount of product in an equilibrium mixture of gases if the pressure is changed.
- If the pressure is increased, the position of equilibriummoves in the direction of the fewest moles of gas.
- You can predict what happens to the amount of product in an equilibrium mixture if the temperature is changed:
- if the temperature is increased, the position of equilibrium moves in the direction of the endothermic reaction
- if the temperature is reduced, the position of equilibrium moves in the direction of the exothermic reaction
- Many reactions, such as burning fuel, are irreversible - they go to completion and cannot be reversed easily.
Comments
No comments have yet been made