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physical chemistry - Coggle Diagram

- - - - chemical reactions in which heat energy is given out
    - - chemical reactions in which heat energy is taken in
  - - - exothermic
    - - exothermic or endothermic
    - - can be endothermic or exothermic
    - - exothermic
- - - - Anhydrous copper(II) sulfate + water ⇌ hydrated copper(II) sulfate
      - White solid turns blue in presence of water
      - Forward reaction add water
      - Reverse reaction heat the hydrated copper(II) sulfate (water evaporates)
    - - Ammonium chloride ⇌ ammonia + hydrogen chloride
      - The white solid (ammonium chloride) breaks down into ammonia and hydrogen chloride (colourless gases) using heat
      - These gases can then react to form ammonium chloride
  - - - if the forward reaction produces more molecules of gas
        
        an increase in pressure decreases the amount of products formed
        
        a decrease in pressure increases the amount of products formed
      - if the forward reaction produces fewer molecules of gas
        
        an increase in pressure increases the amount of products formed
        
        a decrease in pressure decreases the amount of products formed
      - when there are equal numbers of molecules of gas on both sides of the equation, changing the pressure has no effect on the composition of the equilibrium mixture. increasing the pressure will speed up both reactions by the same amount
    - - if the forwards reaction is exothermic
        
        an increase in temperature decreases the amount of products formed
        
        a decrease in temperature increases the amount of products formed
      - if the forward reaction is endothermic
        
        an increase in temperature increases the amount of products formed
        
        an decrease in temperature decreases the amount of products formed
- - - - Add dilute hydrochloric acid to the conical flask. Use a delivery tube to connect this flask to an inverted measuring cylinder upside down in a water trough. Add calcium carbonate chips into the conical flask and close the bung and measure the volume of gas produced in a fixed time using the measuring cylinder. Repeat with different sizes of calcium carbonate chips
    - - Add sodium thiosulfate solution to a flask with dilute hydrochloric acid into a measuring cylinder. Draw a cross on a piece of paper and put it underneath the flask, then add the acid into the flask and immediately start the stopwatch. Look down at the cross from above and stop the stopwatch when it can no longer be seen and repeat using different concentrations of sodium thiosulfate solution.
    - - Dilute hydrochloric acid is heated to a set temperature using a water bath. Add the dilute hydrochloric acid into a conical flask. Add a strip of magnesium and start the stopwatch. Stop the time when the magnesium fully dissolves. Repeat at different temperatures and compare results
    - - Add hydrogen peroxide into a conical flask. Use a delivery tube to connect this flask to a measuring cylinder upside down in water trough. Add the catalyst manganese(IV) oxide to the conical flask and close the bung. Measure the volume of gas produced in a fixed time using the measuring cylinder. Repeat experiment without the catalyst of manganese(IV) oxide and compare result
  - - - more particles exposed when the surface area is increased, therefore, there is more collisions per unit time, increasing rate of reaction.
    - - higher concentration means more reactant particles within the same volume, meaning the probability of random collisions is increased and there are more collisions per unit time, increasing the rate of reactiom
    - - higher pressures means same number of reactants in smaller volumes, meaning particles are closer together so more collisions occur per unit time, increasing the rate of reaction
    - - at higher temperatures, particles have more energy and rate is increased because particles move more, resulting in more collisions per unit time, as more particles have the minimum energy required to react, meaning particles collide with greater intensity meaning successful collisions are more frequent