Summary Chemical ideas

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ISBN-10 0435631497 ISBN-13 9780435631499
263 Flashcards & Notes
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This is the summary of the book "Chemical ideas". The author(s) of the book is/are central Chris Otter. The ISBN of the book is 9780435631499 or 0435631497. This summary is written by students who study efficient with the Study Tool of Study Smart With Chris.

Summary - Chemical ideas

  • 1 Agriculture and Industry

  • How do you calculate the atom economy?

    (Mr of useful product/ Mr of reactants) x 100

  • How would you calculate percentage yield?

    (actual mass/theoretical mass) x 100

  • 1.1 Green chemical process

  • What are potential benefits of using a certain industrial method?

    - high percentage yield

    - solvent can be recycled = does not damage the environment through waste disposal 

    - no toxic products

    - high atom economy

  • How can chemists help farmers improve food?

    - pesticides

    - control soil pH

  • Suggest two reasons why CO isn't released into the atmosphere?

    - it's toxic

    - it can be burnt as a fuel

  • What are the environmental hazards of making benzophenone? 

    - HCl is produced = toxic

    - aluminium compounds are wasted

    - benzene is toxic and hazardess 

  • What are the benefits of recycling?

    - minimise waste

    - reduce energy consumption

    - reduce feedstock consumption

  • What difficulties arise when recycling plastics?

    Sorting different types of plastics as they have similar properties. As a result, most recycled plastics are mixtures of different polymers.

  • Why does recycling aluminium mean a large saving of emitted carbon dioxide compared to other materials e.g. glass?

    The process of extracting aluminium consumes a large amount of energy which is produced from burning fossil fuels. Less fuel is needed to recycle aluminium.

  • What hazard arises when using sodamide? How is it minimised? 

    Reacts violently with water

    Keep under anhydrous conditions 

  • What hazard arises when using pyridine? How is it minimised? 

    Highly flammable

    Keep in  a sealed container & incinerate excess gas 

  • What hazard arises when using hydrogen? How is it minimised? 

    Explosive

    Control the rate of addition of pyridine to sodamide so the hydrogen can be incinerated in the thermal oxidiser

  • What hazard arises when using ammonia? How is it minimised? 

    Toxic

    Use it in solution

  • Give two advantages and two disadvantages of the batch process.

    Advantages - cost effective for small quantities

                             - range of products can be made in the same vessel

     

    Disadvantages - exothermic reactions are more difficult to control

                                   - charging and emptying the reactor is time consuming 

  • Give two advantages and two disadvantages of the continuous process. 

    Advantages - suited to high tonnage production

                             - contamination risk is low

     

    Disadvantages - higher capital cost before any production can occur + not cost effective when run below full capacity

                                   - contamination risk is higher when used for two or more products

  • What is the formula of ammonium sulfate?

    (NH4)2SO4

  • 1.2 Bonding, structure and properties

  • What type of particles do covalent network substances have?

    Atoms

  • What type of particles do metallic substances have?

    positive ions surrounded by delocalised electrons

  • What are the typical properties of ionic compounds in terms of Mpt/Bpt, Hardness, Conductivity, Solubility in water, Solibility in non-polar solvents?

    Mpt/Bpt = high

    Hardness = hard but brittle

    Conductivity = conducts in molten or dissolved in water

    Solubility in water = often soluble

    Solibility in no-polar solvents = generally insoluble

  • What are the typical properties of covalent network compounds in terms of Mpt/Bpt, Hardness, Conductivity, Solubility in water, Solibility in non-polar solvents?

    Mpt/Bpt = very high

    Hardness = very hard 

    Conductivity = does not conduct

    Solubility in water = insoluble

    Solibility in no-polar solvents = insoluble

  • What are the typical properties of metallic compounds in terms of Mpt/Bpt, Hardness, Conductivity, Solubility in water, Solibility in non-polar solvents?

    Mpt/Bpt = high (except mercury)

    Hardness = hard but malleable 

    Conductivity = conduct when solid or liquid

    Solubility in water = insoluble

    Solibility in no-polar solvents = insoluble

  • What are the typical properties of simple molecular compounds in terms of Mpt/Bpt, Hardness, Conductivity, Solubility in water, Solibility in non-polar solvents?

    Mpt/Bpt = low

    Hardness = soft 

    Conductivity = do not conduct

    Solubility in water = usually insoluble, unless molecules contain groups which can hydrogen bond with water

    Solibility in no-polar solvents = usually soluble

  • What type of particles do simple molecular compounds have? What are they held together by?

    Small molecules held together by weak intermolecular forces

  • Explain why many ionic substances are soluble in water, naming the bonds broken and made.

    - ionic bonds broken

    - ion dipole bonds formed

    - hydrogen bonds in water are broken

    - similar strength between bonds broken and made

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Latest added flashcards

Give the systematic name of HCO3-

Hydrogen carbonate

Explain why many ionic substances are soluble in water, naming the bonds broken and made.

- ionic bonds broken

- ion dipole bonds formed

- hydrogen bonds in water are broken

- similar strength between bonds broken and made

Explain how the gas/liquid chromatogram could be used to determine the % composition of each component in the mixture.

- measure the area under the peak

- Find the total area

- % = (area of one peak / total area) x 100

What name is given to the process by which components in a mixture are separated during g.l.c?

Adsorption 

What is the Rf value?

The distance travelled by the substance divided by the distance traveled by the solvent.

Compare the different reactivities of benzene and alkenes towards chlorine. 

In benzene the electrons are delocalised/ spread out. In alkenes electrons are concentrated between two carbons - electrophiles are attracted more to greater electron density in alkenes.

How does a halogen carrier (e.g. AlCl3) allow the reaction between benzene and chlorine to take place?

It can form a dipole with the chlorine gas to form Cl+

Name two types of commercially important material whose manufacture involves the nitration of benzene.

- Dyes

- Explosives

Which enthalpy change in a Born-Haber cycle is the best measure of the stability of the compound concerned? 

Enthalpy change of formation

As time goes by why would a pigment not fade?

It is not affected by sunlight/oxygen/water (just need to remember one)