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Chemistry > C3: Chemical Economics > Flashcards

C3: Chemical Economics Flashcards

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1
Q

What is the formula of magnesium sulfate?

A

MgSO4

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2
Q

Which two factors can determine the rate of reaction?

A
  1. The collision frequency of reacting particles

2. The energy transferred in each of the collisions (i.e. whether each collision is successful)

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3
Q

In terms of the reacting particle model, why does increasing the temperature increase the rate of reaction?

A
  1. At a higher temperature the particles are vibrating and moving more quickly. As a result, it is more likely that they will collide.
  2. Furthermore, the increased temperature mean that the particles are moving with a greater amount of energy. Therefore, particles will be colliding with greater energy, meaning there will be more successful collisions per second.
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4
Q

In terms of the reacting particle model, why do increases in concentration cause an increase in the rate of reaction?

A
  1. If the concentration is increased, there will be more particles of the reactant in the same volume of solution
  2. Therefore, it is more likely particles will successfully collide with each other each second.
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5
Q

In terms of the reacting particle model, why do increases in pressure result in an increase in the rate of reaction?

A
  1. If the pressure is greater, the particles are more crowded and closer together
  2. As a result, they are more likely to collide with each other.
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6
Q

What is a catalyst?

A

A substance that increases the rate of reaction without being chemically changed in the reaction. There are specific catalysts for specific reactions, and are usually only needed in small quantities.

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7
Q

Why do catalysts increase the rate of reaction?

A
  1. They provide a surface for the reacting particles to stick to
  2. This reduces the energy needed by particles to react
  3. As a result, the number of successful collisions increases
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8
Q

Why do powdered substances react faster than large solids and lumps?

A
  1. Chemicals made up of smaller pieces (powders) have a greater total surface area
  2. As a result, particles have a greater area to collide with
  3. Therefore, there will be more successful collisions every second
  4. So rate of reaction increases
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9
Q

Why are fine powders of combustible material dangerous to handle in factories?

A
  • Fine powders have a very large surface area, so they combust extremely quickly
  • As a result a single spark can cause a huge explosion
  • Factories need to be very careful when handling custard powder, flour and powdered sulfur
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10
Q

What is meant by the principles of the conservation of mass?

A

The total mass of the reactants at the start of the reaction is equal to the total amount of product made at the end of the reaction.

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11
Q

What is percentage yield?

A

The amount of product made (actual yield) compared to the amount of scientifically predicted product made (predicted yield). Percentage yield = actual yield (grams)/predicted yield (grams)*100

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12
Q

Why is percentage yield usually less than 100%?

A
  • Loss in filtration
  • Loss in evaporation
  • Loss in transferring liquids
  • Not all reactants react to make product (other/different/unintended reactions happening)
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13
Q

What is atom economy?

A

The amount of desired product produced compared to the total amount of product produced.
atom economy= total Mr of desired products/total Mr of all products * 100

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14
Q

Why do manufacturers want high percentage yields?

A
  • To reduce wastage of reactants

- To reduce costs (and increase profits)

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15
Q

Why do manufacturers want a high atom economy?

A
  • To reduce the production of unwanted products, therefore reducing the amount of waste materials that need to be disposed.
  • By reducing wastage, the process becomes more sustainable
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16
Q

Describe a simple calorimetric method for comparing the energy transferred in combustion reactions.

A
  1. Spirit burner or bottle gas burner used
  2. Water heated in copper calorimeter
  3. Fuel is weighed before and after. Mass of fuel burned recorded
  4. Temperature change recorded
  5. Fair and valid test carried out
17
Q

How can the purity of drugs be tested?

A
  • Pure substances won’t be separated by chromatography - it will all move as one blob
  • Pure substances will have a specific melting and boiling point. Therefore, if the substance is impure, it will have a lower melting point and a boiling point higher than expected
18
Q

Explain why batch processes are used to make pharmaceutical drugs but continue as processes are used to produce chemicals such as ammonia.

A

Pharmaceutical drugs:

  • Involved skilled labour intensive work which can’t be automated
  • Low demand, so less needed

Ammonia:

  • product needed all year round
  • it can be automated as not very labour intensive
19
Q

Describe the advantages and disadvantages of batch and continuous manufacturing.

A

Batch:

  • Flexible (different products can be made using same equipment)
  • Start up costs are relatively low
  • It is labour intensive; equipment needs to be manually controlled
  • It can be tricky to produce the exact same product over and over again

Continous:

  • Production never stops; time not wasted restarting react
  • It runs automatically; lower labour costs
20
Q

Why is it expensive to make and produce drugs?

A
  • Huge research and development costs; highly paid scientist need to find chemical compound
  • Trialling; lengthy human and animal trials need to be carried out. Legal requirements need to be met
  • Manufacturing by batch is labour intensive and can’t be automated
  • Raw materials from plants can sometimes be expensive
21
Q

Explain why it is difficult to test and develop new pharmaceutical drugs that are safe to use.

A
  1. Strict legal requirements need to be made
  2. Lengthy animal and human trials need to be conducted; extremely expensive
  3. If drug has unwanted side affects, whole investment may have been wasted
  4. Many years of testing needed to check for long term impacts
22
Q

Describe how chemicals are extracted from plant sources.

A
  1. Plant material is crushed
  2. Next, it is boiled and dissolved in a suitable solvent
  3. Chromatography strip is used to separate the different chemicals.
23
Q

Why are diamond, graphite and fullerenes all allotropes of carbon?

A

They are just different structural forms of carbon

24
Q

Why is diamond used in cutting tools and jewellery?

A
  • In a diamond, each carbon atom is bonded with 4 other carbon atoms in a giant covalent structure.
  • This rigid covalent structure is what makes the diamond extremely hard
  • The strong covalent bonds take a lot of energy to break, giving diamond a very high melting point.
  • This is also why it is useful as a cutting tool
  • Diamonds are lustrous and colourless
25
Q

Why don’t diamonds conduct electricity?

A

It has no free (delocalised) electrons.

26
Q

Why is graphite used in pencil leads and lubricants

A
  1. Each carbon atom only forms 3 covalent bonds, creating sheets/layers of carbon atoms that can slide over each other
    2 There are weak intermolecular forces between these layers meaning they can be rubbed off onto the paper to leave a black mark
  2. The slipperiness of graphite makes it great to use as a lubricant
27
Q

Why does graphite have a high melting point?

A

Graphite contains lots of strong covalent bonds. Lots of energy is needed to break these bonds meaning that it has a high melting point.

28
Q

Why does graphite conduct electricity?

A

Each carbon atom only forms 3 covalent bonds, leaving each atom with a spare electron - together, they form a sea of delocalised electrons. This is why graphite is a good electrical conductor.

29
Q

Explain why diamond and graphite have a giant molecular structure?

A

Carbon atoms are joined in lattices via covalent bonding. They are described as giant due to the large number of covalent bonds involved.

30
Q

Why can fullerenes be used in drug delivery systems?

A
  1. Their structure forms around another atom or molecule
  2. This molecule is trapped inside the fullerene
  3. This is ideal for a slow release of the drug within a body
31
Q

Explain how the structure of nanotubes enable them to be used as catalysts.

A

Nanotubes have an extremely large surface area, meaning they would be used as a base for catalysts. A catalyst can be painted in a thin layer over the nanotube, providing the catalyst with a huge surface area to catalyse the reactants.

32
Q

What is the formula for sulfuric acid?

A

H2SO4

33
Q

What is the formula of calcium chloride?

A

CaCl2

34
Q

What is the formula of magnesium chloride?

A

MgCl2

Chemistry (6 decks)

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