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16 Cards in this Set
- Front
- Back
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Name the forces between Ca2+ and water molecule in a hydrated calcium ion |
-ion-dipole bonds /forces |
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Why is a non polar molecule (e.g. octan-1-ol) more soluble in a triglyceride oil than in water? |
- main intermolecular bonds between non-polar molecules is id-id - main intermolecular bonds in triglycerides is also id-id - Main intermolecualr bonds between water molecules = H bonds - non - polar molecules only able to form weak id-id bonds to water, much weaker H-bonds - Dissolving only favoured if weaker bonds replaced by stronger/similar bonds - cant happens in water as H-bonds are so strong, but possible in oil as id-id bonds similar in strength - More energy should not be used to break bonds than is released in making bonds if dissolving is to be favourable |
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Describe a hydrogen bond |
- lone pair on O(N or F) forms attractions to delta-positive H atoms - joined to O (N or F)- hydrogen is delta positive due to large electronegativity difference between H and O ( N or F) |
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What is the intermolecular bond between non-polar molecules and how is it formed? |
- Non-polar molecules only have instantaneous dipole -induced dipole intermolecular bonds - Random movement of electrons in molecules creates uneven distribution of charge - This induces a dipole in a neighbouring molecule leading to an attraction - molecules with more electrons will form stronger intermolecular bonds - more energy will needed to overcome/break the stronger intermolecular bonds so boiling points is higher |
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Why would increasing pressure change the equilibrium position in N2(g) +3H2(g) = 2NH3(g) give a reason |
- Equilibrium position will move to the right/products - because there are more moles/molecules (particles ) on the left |
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Why is very high pressure used in a reaction where it would not increase equilibrium ? |
- Faster rate of reaction - As more successful collisions per unit of time/ more frequent collisions |
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Glycerin is a co-product in the manufacture of biodiesel from vegetable oil . Explain what is meant by the term co-product distingiushing it from the by-product |
-co-product is formed in the same reaction that makes the main product - by-product is formed by side/other/unwanted reactions |
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Explain why an exothermic equilibrium process is actually carried out a high temperature |
- must make clear that the increase in rate makes up/ compensates for fall in yield |
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Why is the molecule CF3CL polar? |
- C-CL bonds and C-F bonds have different polarities - The dipoles/charges do not cancel out |
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Describe the stationary and middle phase in Gas-liquid chromatography |
- Stationary phase = high billion liquid on solid support - Mobile phase - inert carrier gas such as N2 or Ar |
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A reaction involves the dehydration of an organic molecule. Give another name for this type of reaction |
- Elimination |
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Disadvantage/advantage of adding N nitrates to the soil |
- N is essential nutrient for plant growth - nitrates can be leached/ washed out of soil into rivers where they can cause eutrophication |
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Describe the importance of the environment having industrial reactions with high atom economies |
-little waste/ most atoms or reagents used |
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What does the 'V' in the Calcium ntirate (v) indicate |
- oxidation sate/number of nitrogen |
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Why is Calcium nitrate (V) used as fertiliser |
- Contains nitrogen which crops plants need |
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How will feasibility of a reaction with known entropy change of system be affectedas temperature rises if the enthalpy change of reaction is exothermic? |
State : ΔS total= ΔS system + ΔS surroundingsΔS surroundings = - ΔH / T will be positive as ΔH is negative.As temp (T) rises the value of - (ΔH / T) decreases (value of ΔH is constant )(assume - unless told otherwise- that ΔS system is independent of temperature) soΔS total becomes smaller and reaction becomes less feasible. |
