C3 Chemical economics

Question 1

What are the two types of bonds that hold atoms together?

Answer 1

Covalent bonds

Ionic bonds

Question 2

How is an ionic bond is formed?

Answer 2

When a positive ion and negative ion are attracted to each other

Question 3

How is a covalent bond formed?

Answer 3

Share of electrons

Question 4

Give an example of a slow and fast reaction

Answer 4

Rusting

Explosion and burning

Question 5

What apparatus is needed to measure the amount of gas produced?

Answer 5

Flask

Gas syringe

Question 6

Explain why a reaction stops

Answer 6

A reaction stops because the limiting reactant is all used up

Question 7

Define rate of reaction

Answer 7

The amount of product produced in a given amount of time period

Question 8

The amount of product produced is directly proportional to the amount of limiting reactant used

Answer 8

-

Question 9

Why is this true?

Answer 9

The reaction will stop as soon as all the limiting reacted is used up

Question 10

When do chemical reactions take place?

Answer 10

When reacting particles collide

Question 11

Describe the effect of changing temperature on rate of reaction

Answer 11

The rate of reaction increases because particles will have more energy and the chances of successful collision which initiate the reaction occurring will increase, the frequency of collisions will also increase

Question 12

Describe the effect of increasing concentration on the rate of reaction

Answer 12

The more concentrated a solution is, the more solute is dissolved in the solvent. The rate of reaction will increase as the particles are crowded , having more collisions. They don’t gain any extra energy

Question 13

Describe the effect of having a greater pressure on the rate of reaction

Answer 13

Same particles in smaller area. No extra energy is added, frequency on collisions increase

Question 14

What does the rate of reaction depend on?

Answer 14

• collision frequency of reacting particles

- whether the energy is transferred ( successful or unsuccessful)

Question 15

Describe the term explosion

Answer 15

A very fast reaction which releases a large volume of gaseous products

Question 16

Describe the term catalyst

Answer 16

Catalyst is a substance that increases rate of reaction yet remains unchanged at theme of the reaction

Question 17

Explain the dangers of fine combustible powders in factories

Answer 17

Can cause naked flames or sparks

Question 18

Explain the principle of conservation of mass

Answer 18

Mass is conserved because no atoms are created or destroyed

Question 19

Possible ways why percentage yield isn’t 100%

Answer 19

Filtration 
Evaporation 
Not all reactants react to make the product 
Transferring liquids 
Heating

Question 20

Why does the industry want the atom economy to be high as possible

Answer 20

To reduce the production of unwanted products

To make the process more sustainable

Question 21

Describe a simple calorimetric method

Answer 21

Use of spirit burner
Heating water in a copper calorimeter
Measuring the temperature change and amount of fuel burnt
Fair tests:

Question 22

List factors of cost whilst making medicines

Answer 22

Research and testing
Raw materials 
Development 
Labour costs
Energy costs 
Marketing

Question 23

Describe how chemicals are extracted from plants

Answer 23

Crushing
Boiling and dissolving in solvent
Chromatography

Question 24

Why are batch processes used to make pharmaceutical drugs and continuous processes used to ammonia?

Answer 24

Pharmaceutical drugs’ supply varies at times and uses special chemicals which are of high value

Question 25

Explain why diamond, Buckminster fullerene and graphite are all forms of carbon

Answer 25

They are all allotropes of carbon- different forms of carbon in the same physical state. Although diamonds and graphite differ in structure

Question 26

List the physical properties of diamond

Answer 26

Lustrous
Colourless 
Transparent
Hard 
High melting point 
Insoluble in water
Doesn't conduct electricity

Question 27

List the physical properties of graphite

Answer 27

Black 
Lustrous 
Opaque 
Slippery 
Insoluble in water
Conducts electricity

Question 28

Nanotubes can be used to strengthen graphite in tennis rackets

Answer 28

-

Question 29

Nanotubes can be used as semiconductors in electrical circuits

Answer 29

-

Question 30

Explain why diamond, graphite and buckminster fullerene are allotropes of carbon

Answer 30

They are in the same state at room temperature , but their carbon atoms are arranged differently

Question 31

Explain in terms of structure why diamond is used in cutting tools and jewellery

Answer 31

They are used as cutting tools because they are hard and have a high melting point
They are used in jewellery because there lustrous appearance makes them highly valued gemstones

Question 32

Explain in terms of properties why graphite is used:

• in pencil leads
• in lubricants

Answer 32

Graphite is used as pencil leads because it is slippery and wears off easily on paper leaving a fine black line which is readable
It is also used in lubricants as it works at high temperature and is slippery

Question 33

Explain in terms of structure and bonding why:

• Diamond has a high melting point and is hard
• Diamond doesn’t conduct electricity

Answer 33

• Doesn’t contain delocalised electrons so it can’t conduct electricity
• Contains a lot of covalent bonds
• why is it hard?

Question 34

Explain in terms of structure and bonding why Graphite:

• conducts electricity
• has a high melting point
• is slippery

Answer 34

• conducts electricity because it has delocalised electrons
• is slippery because graphite is a layered structure where each carbon atom is joined to 3 others by covalent bonds. There are only weak forces between the layers, so the layers can slide over each other
• has a high melting point because the carbon atoms have strong covalent bonds

Question 35

Explain why diamond and graphite have a giant molecular structure

Answer 35

Each molecule contains very many atoms joined together by covalent bonds. As covalent bonds are very strong, and there are many of them in each molecule, the melting and boiling points of substances with giant molecular structures are high.

Question 36

Explain why fullerenes can be used in new drug delivery systems

Answer 36

Scientists have discovered how to ‘cage’ radioactive metal atoms and drug molecules inside fullerenes. These fullerenes have potential use as new drug delivery systems. For example, they can be coated with chemicals that cause them to gather next to cancer cells after being injected into the body. In this way, the drug can be delivered to its target without damaging normal cells.

Question 37

Explain how the structure of Nanotubes enables them to be used as catalysts

Answer 37

Nanotubes can act as catalysts, especially when they are stacked side by side. They have a huge surface area compared to their volume, allowing a high collision frequency with reactant molecules. Their properties are modified to make them effective catalysts by attaching other substances, such as nitrogen or iron, to their surface.