Chemistry 3_ measuring energy.txt

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Chemistry 3_ measuring energy.txt
2012-05-23 17:36:48
chemistry measuring energy

chemistry 3 measuring energy
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    • author "me"
    • fileName "Chemistry 3: measuring energy"
    • tags ""
    • description ""
    • Energy is measured in...
    • Joules (J)
  1. How many joules in 1 calorie?
    4.2J = 1C
  2. Energy on food is measured in...
    kilocalories (kcal)
  3. What food provides large amounts of energy?
  4. What food provides some energy?
  5. What food provides little energy?
  6. How is excess energy stored?
    As fat
  7. If a person stores too much fat, they become..
  8. Obesity can lead to....
    Heart disease, diabetes
  9. How can the amount of energy produced be measured?
  10. A chemical change is usually accompanied by....
    An energy change
  11. List the steps of using calorimetry
    • Place exactly 100g of water in a calorimeter and measure its temp.
    • Measure the mass in grams of the fuel to be burned
    • Burn the fuel under the water in the calorimeter
    • Record the new temp to calculate the temp change
    • Weigh the fuel and calculate how much fuel has been used
  12. What is a calorimeter?
    A container made of glass or metal with a wooden lid.
  13. How can energy produced in chemical reactions be measured?
    By mixing reactants in an insulated container so the temp change can be measured before heat is lost
  14. When can measuring temp change in an insulated container be suitable?
    In neutralisation, and solid+water reactions
  15. When new substances are produced, what happens to bonds?
    They are broken and new can be made
  16. What does ENDOTHERMIC mean?
    Energy is being taken in
  17. What does EXOTHERMIC mean?
    Energy is being given out
  18. BREAKING a chemical bond requires a lot of energy. This makes the process..
  19. MAKING a chemical bond releases energy. This makes the process..
  20. If MORE energy is required to break old bonds than is released to make new bonds, the overall process is...
  21. If more energy is RELEASED in making new bonds than is required to break old bonds, the overall process is...
  22. How can energy changes be illustrated?
    Using an energy level diagram
  23. What would you see on an ENDOTHERMIC energy level diagram?
    The reactants would have less energy than the products
  24. What would you see on an EXOTHERMIC energy level diagram?
    the reactants would have more energy than the products
  25. How is activation energy lowered?
    Using a catalyst e.g. a transition metal
  26. What is activation energy?
    The energy needed to start a reaction.