• Created by: Bonnie
  • Created on: 07-06-14 13:54
What is rate of reaction?
Time taken between starting and stopping
1 of 45
What does reaction measure?
Measures rate of disappearance of reactant
2 of 45
What is an example of a slow reaction?
3 of 45
What is an example of a fast reaction?
4 of 45
An example to suggest?
Magnesium and Hydrochloric Acid (Mg + 2HCl -> MgCl2 + H2
5 of 45
How to do this...
1) Clean magnesium ribbon 2) Place in test tube 3) Set up apparatus 4) Shake flask to mix 5) Start stopwatch 6) Record volume of hydrogen in gas syringe every half minute
6 of 45
Methods to measure rates
Colour changes, temperature changes, formation of precipitate and time taken to react
7 of 45
Amount of product formed is..
directly proportional with amount of limiting reactant
8 of 45
What do manufactures use powder instead of lumps?
Powder has larger surface area as particles that were inside the lump become exploded and crushed.
9 of 45
What are explosions?
Very fast reactions in which a large volume of hot gases are released in a short amount of time
10 of 45
What is an example of an explosion?
Hydrogen beings ignoted (2H -> O(2) + 2H(2)O
11 of 45
What is the collision theory?
The principle that reaction only occurs when particles collide with each other, and that reactions have sufficient minimum energy called Activation Energy
12 of 45
What is a catalyst?
Substance which increases that rate, not yield. And remains unchanged throughout reaction.
13 of 45
Why is a catalyst used?
To reduce costs.
14 of 45
What is an example of a catalyst?
Iron in haber process, hydrogen peroxide in bleach
15 of 45
What does A(r) mean?
Relative atomic mass
16 of 45
What does M(r) mean?
Relative formula mass
17 of 45
Why is mass conserved?
No atoms are created or detroyed
18 of 45
Equation for percentage yield?
(actual yield / predicted yield) x 100
19 of 45
What does increasing the amount of reactants do?
Increases amount of product produced, but percentage yield stays the same under the same conditions
20 of 45
Why will percentage yield never be 100%?
Reaction may not go to completion because it is reversible, some product may not be lost when it being prepared, reactants react differently
21 of 45
Why is it important in industry?
To avoid wasting reactant (reducing costs)
22 of 45
Equation for atom economy?
(m(r) of desired products / total m(r) of all products) x 100
23 of 45
Why is waste bad in industry?
Have to be disposed of, contributes to pollution, raises costs of production, make ineffective use of resources
24 of 45
What does low atom economy mean?
Low atom economy means few atoms in reactants have been converted into the desired product
25 of 45
What is an exothermic reaction?
Energy is transferred into the surroundings (energy is released) (temperature rise) (bond making)
26 of 45
What is an endothermic reaction?
Energy is taken from surroundings (energy absorbed) (temperature fall)
27 of 45
Examples of exothermic reactions?
combustion, oxidation reactions, neutralisation reactions
28 of 45
Examples of endothermic reactions?
photosynthesis, thermal decomposition
29 of 45
What is calorimetry?
Method used to measure the energy transferred in chemical reactions
30 of 45
1) Fuel is put into spirit burner, then weighed. 2) Calorimeter is filled with known mass of water. 3) Temperature of water is measured. 4) Wick of spirit burner is lit so flame warms up water 5) Spirit burner weight and water temperature is recorded
31 of 45
Equation for energy transferred.
Mass of water heated x Temp change x 4.2
32 of 45
Equation for energy/gram
Energy transferred / mass of fuel burnt
33 of 45
What are the variables in calorimetry?
Volume of water used, starting temperature, height of calorimeter from spirit burner
34 of 45
Examples of continuous processes?
Ammonia (haber process), sulfuric acid, chlorine
35 of 45
Examples of batch processes?
Pharmaceuticals, wine, specialty chemicals
36 of 45
What are factors that affect cost in r&d?
Raw materials, development, research and testing, labour costs, energy costs, marketing
37 of 45
What is purity tested by?
Thin layer chromotography
38 of 45
Characteristics of diamond?
Insoluble in water, lustrous, colourless and clear, high melting point, does not conduct electricity
39 of 45
Why does diamond not conduct?
Electrons are used in covalent bonds
40 of 45
What is diamond used for?
Cutting tools, as it is hard and has a high melting point. Jewellery, as it is lustrous.
41 of 45
Characteristics of graphite?
Black, lustrous, opaque, high melting point, soft and slippery, can conduct electricity.
42 of 45
Why can graphite conduct?
Carbon atoms are in layers therefore there are delocalized electrions
43 of 45
What are graphites and diamonds ...... of carbon?
44 of 45
What does allotropes mean?
Different forms of the same element in the same physical state
45 of 45

Other cards in this set

Card 2


What does reaction measure?


Measures rate of disappearance of reactant

Card 3


What is an example of a slow reaction?


Preview of the front of card 3

Card 4


What is an example of a fast reaction?


Preview of the front of card 4

Card 5


An example to suggest?


Preview of the front of card 5
View more cards


No comments have yet been made

Similar Science resources:

See all Science resources »See all c3 resources »