Chemistry GCSE OCR Gateway C4 Revision Cards

Chemistry GCSE OCR Gateway C4 Revision Cards- Chemical Economics

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  • Created by: Pheebie
  • Created on: 08-06-11 13:41

Acids and Bases

Acid, Weak acid, Neutral, Weak alkali, Alkali. 

0             3              7          10              14

  • Indicator and dye that changes colour and indicating pH. 
  • Acids and based neutralise each other.
  • Acid + base ---> salt + water e.g. H+ +OH- ---> H20.
  • Modern industry uses lots of Sulfuric acid e.g. for car batteries, fertilisers, detergents, dry cleaning and prepareing metak surfaces.


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Reactions of Acid

  • 1.Acid + metal-oxide ---> salt + water.
  • 2.Acid + metal-hydroxide --->  metal + salt +water.
  • (1 and 2 are neutralisation reactions)
  • 3.Acid + Carbonate ---> salt + water + carbon dioxide.
  • 4.Acid + ammonia ---> ammonia salt.
  • (4 makes ammonia products such as fertilisers.)


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Relative Formula Mass

  • Relative atomic mass:- Helium= 4
  • It's how heavy an atom is.
  • RFM= bottom two numbers you add or times the numbers together.


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Calculating Masses in Reactions

  • 1. Write a balanced equation.
  • 2. Work out the Mr.
  • 3. Then use the equation of dividing by one and multiplying by the other to get the RFM for the exact amount. e.g.
  •  48g of Mg .... 80g of Mg
  • 1g of Mg    ....1.67g MgO
  • 60g of Mg  .... 100g Mg O


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Percentage Yields

  • Compares actual and predicted yields.
  • Percentage yield= (actual yield/ predicted yield) x 100
  • (It will always give you a number between 0-100)
  • Not normally 100 because:- evaporating, heating, filtering and transferring liquid. 


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  • Plants need NPK to grow:- Nitrogen, Phosphorus and Potassium. 
  • They replace missing elements increasing crop yields, e.g.
  • Ammonia + Nitric acid ---> Ammonia nitrate.
  • They can be made in the lab by titration methods.
  • Percentage Mass= ((Ar x # of Atoms) / Mr) x 100
  • Fertilisers can damage lakes and rivers by eutophication e.g. algal blooms.


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Minimising Production Costs


  • Price of energy.
  • Cost of raw materials.
  • Labour costs.
  • Equipment costs.
  • Rate of production.

Reducing Costs:-

  • Optimum conditions chosen to get lower costs.
  • Low percentage yields are okay if starting materials can be recycled, but sufficient enough to make a high amount each day.


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The Haber Process

  • The Haber process is a reversible reaction. 
  • N2 + 3H2 <----> 2NH3


  • 200 atmospheres of pressure.
  • 45c temperature.
  • Iron catalyst.
  • Continuous process 


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Allotrope's of Carbon

  • Diamonds:- Jewellery, cutting tools, rigid, covalent, doesn't conduct electricity, no free electrons, 4 covalent bonds.
  • Graphite:- Each Carbonate has covalent bonds which slide over each other, conduct electricity.
  •  Buckminsterfullerene:- Carbon (C60) 3 covalent bonds, can form nano tubes.


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Batch Process

Key Points:- It's flexible, low start up costs, labour sensitive- each batch is man-made, they're are times when it's not making anything, contamination is likely, it's more cost effective to make small drugs orders.

Factors effecting Costs of Drugs:- Market research, research and development, drugs trialling, market, advertising and manufacturing costs, the price per dose.

Extract drugs by:- Crushing the plant, then dissolving it in a suitable solvent, chromatography extracts the substance. 


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  • Washing at low temperatures saves energy, but high temperatures melt greasy deposits so detergents can break it down easily, but some fabrics such as wool shrink.
  • Biological washing detergents contain enzymes, if they get washed in over 40c they denature and stop working. The low temperatures use less energy, less CO2 and don't contribute to the green house effect.  
  • Detergents work by sticking to both grease and water.
  • Most detergents are salts.
  • Different solvents dissolve different stains.


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Dry Cleaning

  • Uses solvents such as trichloroethene.
  • It doesn't use water.
  • The solvent is strongly attracted to oily molecules and it breaks them down.


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Water Purity

  • There are a variety of water sources in the UK e.g. Surface water (reservoirs, lakes and rivers) and groundwater (aquifers).
  • Water is Purified in plants by: being put through a mesh filter, then sand filtered, then sedimentation filtered, and finally chlorinated.
  • Tap water contains impurities:- Nitrates (residue from fertilisers 'run off'), Lead Compounds (from old lead pipes), Pesticides residues ('run off').
  • You can distil sea water, it's expensive, but good for dry coastal countries such as Kuwait. 


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Annie R

good cards thanks! its C4 though isn't it?


Yes it is! All this revision is really getting to me! Thank you :)


THANK YOU SOOOOOOOOO MUCH! This is so perfect for revising! I am also going to use all of your other GCSE science ones...Thank you!!!!!


Thank you so much! You have no idea how much these help!


Thanks for the feedback :-)


really helpful thankyou. please do a C5 one these cards make everything so much easier!

Sam Jeal

really good, thanks

on the harber process isnt it 450c?

Jordan Peacock



This is fantastic!


This has helped me so much, thank you! Any C5 ones?


Please could you do some for C5?? These are amazing by the way!!


Thanks so much for all the science revision resources, really helping!

One question what does Mr stand for in calculating masses?x




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