C3 Chemical economics Flashcards
What are the two types of bonds that hold atoms together?
Covalent bonds
Ionic bonds
How is an ionic bond is formed?
When a positive ion and negative ion are attracted to each other
How is a covalent bond formed?
Share of electrons
Give an example of a slow and fast reaction
Rusting
Explosion and burning
What apparatus is needed to measure the amount of gas produced?
Flask
Gas syringe
Explain why a reaction stops
A reaction stops because the limiting reactant is all used up
Define rate of reaction
The amount of product produced in a given amount of time period
The amount of product produced is directly proportional to the amount of limiting reactant used
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Why is this true?
The reaction will stop as soon as all the limiting reacted is used up
When do chemical reactions take place?
When reacting particles collide
Describe the effect of changing temperature on rate of reaction
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
Describe the effect of increasing concentration on the rate of reaction
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
Describe the effect of having a greater pressure on the rate of reaction
Same particles in smaller area. No extra energy is added, frequency on collisions increase
What does the rate of reaction depend on?
- collision frequency of reacting particles
- whether the energy is transferred ( successful or unsuccessful)
Describe the term explosion
A very fast reaction which releases a large volume of gaseous products
Describe the term catalyst
Catalyst is a substance that increases rate of reaction yet remains unchanged at theme of the reaction
Explain the dangers of fine combustible powders in factories
Can cause naked flames or sparks
Explain the principle of conservation of mass
Mass is conserved because no atoms are created or destroyed
Possible ways why percentage yield isn’t 100%
Filtration Evaporation Not all reactants react to make the product Transferring liquids Heating
Why does the industry want the atom economy to be high as possible
To reduce the production of unwanted products
To make the process more sustainable
Describe a simple calorimetric method
Use of spirit burner
Heating water in a copper calorimeter
Measuring the temperature change and amount of fuel burnt
Fair tests:
List factors of cost whilst making medicines
Research and testing Raw materials Development Labour costs Energy costs Marketing
Describe how chemicals are extracted from plants
Crushing
Boiling and dissolving in solvent
Chromatography
Why are batch processes used to make pharmaceutical drugs and continuous processes used to ammonia?
Pharmaceutical drugs’ supply varies at times and uses special chemicals which are of high value
Explain why diamond, Buckminster fullerene and graphite are all forms of carbon
They are all allotropes of carbon- different forms of carbon in the same physical state. Although diamonds and graphite differ in structure
List the physical properties of diamond
Lustrous Colourless Transparent Hard High melting point Insoluble in water Doesn't conduct electricity
List the physical properties of graphite
Black Lustrous Opaque Slippery Insoluble in water Conducts electricity
Nanotubes can be used to strengthen graphite in tennis rackets
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Nanotubes can be used as semiconductors in electrical circuits
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Explain why diamond, graphite and buckminster fullerene are allotropes of carbon
They are in the same state at room temperature , but their carbon atoms are arranged differently
Explain in terms of structure why diamond is used in cutting tools and jewellery
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
Explain in terms of properties why graphite is used:
- in pencil leads
- in lubricants
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
Explain in terms of structure and bonding why:
- Diamond has a high melting point and is hard
- Diamond doesn’t conduct electricity
- Doesn’t contain delocalised electrons so it can’t conduct electricity
- Contains a lot of covalent bonds
- why is it hard?
Explain in terms of structure and bonding why Graphite:
- conducts electricity
- has a high melting point
- is slippery
- 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
Explain why diamond and graphite have a giant molecular structure
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.
Explain why fullerenes can be used in new drug delivery systems
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.
Explain how the structure of Nanotubes enables them to be used as catalysts
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.
