C8 - Rates and equlibrium.

C8 - Rates and equlibrium.

• you can find out the rate of reaction by monitering amount of reactants used over time or products made over time.
• Gradient tells you the rate of reaction. Steeper gradient = faster reaction. 
• To calculate ROR at specific time draw the tangent to the curve, then calculate its gradient.

• Particles must collide with a minimum amout of energy before they react. 
• Activation energy =  minimum amout of energy before they react
• Rate increases if surface area to volume ratio of any solid reactants are increased, this increases the frequency of collisions between reacting particles.

• temperature increase = quicker reactions. 
• increasing temp increases the frequency particles collide at and they move more frantically.
• More collisions in a given time result in a reaction as the particles have a higher energy that is larger than the activation energy.

• Increasing concentration = increases frequency of particle collision.
• Increasing pressure = increases frequency of particle collision.

• Speeds up rate of reaction but it is not used up itslef during the reaction. Chemically unchanged.
• Different catalysts needed for different reactions. 
• Used in industry to increase ROR and reduce energy costs.

• One reaction exothermic and one reaction endothermic. 
• In a reversible reaction the amount of energy transferred one way is exactly the same the other way.

• In a closed system the rate of forward and reverse reactions is equal at equilibrium. 
• Changing reaction conditions can change amount of products and reactants in a mixture at equilibrium.

• Increasing pressure favours reaction that forms less moleules of gas. 
• Deacrising pressure favours reaction that forms more molecules of gas.
• Incraeasing temperature - favours endothermic reaction. 
• Decreasing temperature - favours exothermic reaction.