Investigating chemicals/ identifying substances

Task 1 Your company has asked you to research methods of identification for various chemicals – in other words, how could you tell what they are from looking at their properties? Fill in the excel spreadsheet after finding out about each chemical. If you complete this task correctly, you will meet grading criterion P1. Task 2 Your company has asked you to investigate the conductivity of copper wire. This means how well it conducts (allows to flow) electricity. You can find this out by looking at the electric current through a sample of wire. A strong/high/fast current (Amps) means high conductivity. A weak/low/slow current means low conductivity. Use different lengths of wire and different numbers of strands to investigate, and draw graphs to show your findings. Discuss the type of graph needed with your teacher. If you complete this task correctly, you will meet grading criterion P2.

Task 3 The air that makes up the atmosphere surrounding us contains various gases including the oxygen that we need to live. Is air an element, a compound or a mixture? How could you show this? Name 2 elements and 1 compound found in air. Make a poster showing the above information, and include a pie chart showing the composition of air.  If you complete this task correctly, you will meet grading criterion M1.

Task 4 The table shows some properties of metals used in overhead power lines. Metal Density (kg/m3) Electrical conductivity Cost per kg (£) Aluminium 2700 3700 2.00 Steel 7800 1000 0.20 a)    Give two reasons why aluminium is better suited than steel to make overhead power lines. b)    Give one reason why steel is often mixed in with aluminium in overhead power lines. If you complete this task correctly, you will meet grading criterion M2.

Task 5 Many metals melt at quite low (for chemists!) temperatures e.g 300-1000oC. What is it about the structure of the chemicals in Task 1 which makes their melting points so much higher? If you complete this task correctly, you will meet grading criterion D1.