CC14
- Created by: Lottie Deutsch
- Created on: 02-12-17 16:24
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- C14a
- rates of reaction
- you can change the rate of reaction by changing variables
- size of pieces of solid reactant used
- concentration of solutions
- we can measure the rate of reaction by checking the volume of mass of the reactants
- FOR EXAMPLE
- THE CHANGE IN RATE OF REACTIONS BETWEEN MAGNESIUM STRIPS AND GRANULES REACTION WITH SULPHURIC ACID
- USE A GAS SYRINGE TO MEASURE THE AMOUNT OF GAS ESCAPING - THIS WAY NONE IS LOST AS THERE IS A BUNG PREVENTING IT
- WE CAN SEE THE RATE OF REACTION IS FASTER FOR THE GRANULES AS THE GRAPH LINE IS STEPPER
- THIS HAPPENS BECAUSE THE GRANULES ARE SMALLER PIECES THAN THE STRIPS
- OR
- PUT THE CONICAL FILLED WITH CALCIUM CARBONATE AND HYDROCHLORIC ACID ON A WEIGHING SCALE
- AS IT'S MASS DECREASES WE KNOW CO2 IS ESCAPING SHOWING A REACTION IS OCCURING
- THE CHANGE IN RATE OF REACTIONS BETWEEN MAGNESIUM STRIPS AND GRANULES REACTION WITH SULPHURIC ACID
- FOR EXAMPLE
- the steeper the line on a graph the faster the rate of reaction (REFER TO GRAPH ON PG. 250)
- you can change the rate of reaction by changing variables
- factors that affect rate of reaction
- activation energy is the amount of energy needed for there to be a successful collision
- a successful collision occurs when to particles hit each other with enough energy and the right orientation to break others bonds so they can rearrange to form and new substance
- higher the frequency (no. of collisions in a certain amount of time)
- and higher the energy (no, of particles that have the right amount of activation energy) more reactions occur
- and high temp. affect rate of reaction
- high pressure of gases
- large surface area
- how high concentration
- increases RoR - there are more particles to react with so collisions occur more frequently
- the particles can access more parts of the substance meaning more collisions and higher rate of reaction
- how high concentration
- increases rate of reaction because more particles are squeezed closer together meaning bigger chance they collide
- large surface area
- increases rate of reaction as gives reactant particles more energy and so they speed up and collide more often
- Untitled
- high pressure of gases
- CORE PRATICAL
- METHOD
- 1. PLACE MARBLE CHIPS IN A BEAKER WITH A PIECE OF PAPER WITH A CROSS UNDER-NEATH
- 2. ADD THE DILUTE HYDRO-CHLORIC ADIC
- 3. TIME HOW LONG IT TAKES FOR THE CROSS TO NO LONGER BE VISIBLE
- REPEAT WITH POWDER AND SMALL MARBLE CHIPS
- 3. TIME HOW LONG IT TAKES FOR THE CROSS TO NO LONGER BE VISIBLE
- 2. ADD THE DILUTE HYDRO-CHLORIC ADIC
- 1. PLACE MARBLE CHIPS IN A BEAKER WITH A PIECE OF PAPER WITH A CROSS UNDER-NEATH
- METHOD
- activation energy is the amount of energy needed for there to be a successful collision
- catalysts affect on rate of reaction
- catalysts are substances that speed up a rate of reaction without being changed themselves or effecting the product of that reaction
- catalysts are useful in business because it means high temps aren't needed and reaction occur faster - they are also not used up
- catalysts lower the activation energy meaning particles require less energy for a reaction to occur
- refer to graph on pg. 257 - it shows us that the overall energy change is the same but the catalyst just lowers the activation energy
- Ea - activation energy Ec - activation energy with catalyst
- you know enzymes - large protein molecules which have a specific active site nd if temp gets too high they denature no longer have specific active site
- refer to graph on pg. 257 - it shows us that the overall energy change is the same but the catalyst just lowers the activation energy
- catalysts lower the activation energy meaning particles require less energy for a reaction to occur
- rates of reaction
- Conclusion: the powder and the small marble chips have faster reactions as they have a larger surface area
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