# Rates summary

• Created by: h98
• Created on: 24-11-15 18:02
• RATES
• change in concentration per unit time   (mol1dm-3)
• factors affecting rate
• surface area: larger surface area, more frequent and more successful collisions.
• catalyst: speeds up rate of reaction without being used up, lowers Ea by providing and altering the pathway
• temperature: higher temperature, more kinetic energy, more frequent and more successful collisions.
• concentration: higher concentration, more frequent collisions, more successful collisions.
• pressure: increase pressure, more particles per unit volume, more frequent and more successful collisions
• order of reaction
• first order: the rate of reaction is directly proportional to the concentration
• second order: the rate of reaction is proportional to the square of the change in concentration
• zero order: the rate of reaction is not affected by the change in concentration.
• rate equations
• rate = k [X][Y]2
• [X] first order [Y]2second orderdo not include zero order int this equation
• overall order: add the powers
• concentration-time graphs
• 1. label axis2.half life tells if its 1st order or not3.show minimum of 2 half lives4state the values of the half lives and the units
• calculation rate:1. draw tangent following curve 2.dy/dx include units 3.initial rate=0 seconds4.must cross line at time=0 seconds5.label axis, include units
• factors affecting rate
• surface area: larger surface area, more frequent and more successful collisions.
• catalyst: speeds up rate of reaction without being used up, lowers Ea by providing and altering the pathway
• temperature: higher temperature, more kinetic energy, more frequent and more successful collisions.
• concentration: higher concentration, more frequent collisions, more successful collisions.
• pressure: increase pressure, more particles per unit volume, more frequent and more successful collisions
• molar ratios:A+2B --> C+Dwhat is the rate of formation of the compound C if the rate of B is 10moldm-3?2:1 molar ratio, 10/2=5 moldm-3
• RATES
• change in concentration per unit time   (mol1dm-3)
• order of reaction
• first order: the rate of reaction is directly proportional to the concentration
• second order: the rate of reaction is proportional to the square of the change in concentration
• zero order: the rate of reaction is not affected by the change in concentration.
• rate equations
• rate = k [X][Y]2
• [X] first order [Y]2second orderdo not include zero order int this equation
• overall order: add the powers
• concentration-time graphs
• 1. label axis2.half life tells if its 1st order or not3.show minimum of 2 half lives4state the values of the half lives and the units
• calculation rate:1. draw tangent following curve 2.dy/dx include units 3.initial rate=0 seconds4.must cross line at time=0 seconds5.label axis, include units