Chemistry C2B

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Rates of reaction: Marble Chips and HCL Acid [3]
Gas is formed.Collected by gas syringe to measure volume of gas produced. Look at reaction in mass to see the rate of reaction - mass is lit over a period of time
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Rate of Reaction: Magnesium strips
Time taken for Mg to disappear. The mg reacts with dilute HCL, Faster it dissolved, faster it disappears
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Rate of Reaction: Sodium thiosulfate and acid
Clear to CLOUDY Solution // measure time taken for cross to disappear underneath on tile due to cloudiness
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Rate of reaction formals [2]
Amount of reactant used/ Time Amount of reactant produced / Time
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When do chemical reactions occur
when the reacting particles collide with enough energy, the minimum amount of energy required is the activation energy
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Changing rate of reaction factors
Temp, concentration, pressure, surface area
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Concentration
increase concentration = faster rate of reaction. Increasing concentration increases the frequency of SUCCESSFUL collisions so the rate of reaction increases as particles are packed more closely together
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Temperature
Raising the temp = gives the particles MORE ENERGY. This increases the speed of the particles so they collide more FREQUENTLY and more ENERGETICALLY with the activity energy
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Pressure
Increasing pressure reduces sp[ace for particles so the particles get closer together ... Increases frequency of SUCCESSFUL collisions which increases rate of rate of reaction
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Surface area
same concentration concentration and temp (control variables) Increasing surface area increases frequency of collisions
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What is a catalyst
substances which speed up chemical reactions without being changed or used up during the reaction.
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Example of use of catalyst
Hydrogen peroxide --- water + oxygen // This reaction is VVVVV SLOW!!
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How to speed up this reaction of hydrogen peroxide
Use manganese oxide catalyst -- Oxygen is produced much more rapidly and so syringe is filled up faster with oxygen until all Hperoxide has reacted and broken down
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Catalysts [2[]
can be used to change the rate of a reaction and different catalysts are used diff reactions
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Advantages of catalyst [6]
less energy/pressure/temp used, money is saved because the plant doesn't need to run machinery for as long, Reusable, speeds up reactions, allow reactions to happen at lower temps so good for sustainable development as it saves energy, Lower produc
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Disadvantages of catalyst [3]
V expensive to buy, Catalysts can be poisoned by impurities an stop working, can be toxic
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what happens when chemical reactions occur
energy is transferred to/from its surroundings
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Other cards in this set

Card 2

Front

Rate of Reaction: Magnesium strips

Back

Time taken for Mg to disappear. The mg reacts with dilute HCL, Faster it dissolved, faster it disappears

Card 3

Front

Rate of Reaction: Sodium thiosulfate and acid

Back

Preview of the front of card 3

Card 4

Front

Rate of reaction formals [2]

Back

Preview of the front of card 4

Card 5

Front

When do chemical reactions occur

Back

Preview of the front of card 5
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