KQ: How can we carry out graphical analysis? LO: To be able to draw graphs and carry out graphical analysis of experimental data.

Volume of Gas Produced by Yeast at varying Temperatures  The effects of varying temperatures on the amount of gas produced can be tested using everyday school equipment.  The yeast and glucose solution can be left in water baths of varying temperatures and volume of gas produced recorded.

Hypothesis  What factors are likely to affect the amount of gas produced by the yeast? Make a quick list!  How might changing the temperature affect the amount of gas? Use your research to come up with a hypothesis!

David’s results Temp ( o C)Volume of gas (cm 3 ) What is wrong with this table? What sort of graph should we plot? Can we tell how long the reactions were allowed to run for?

What is good about this graph? What is bad about this graph? Why is there a big drop at 25 o C? Is it a large drop? What does the graph not show? David’s Graph

Rules for graphing  We need to fully label the graph so that others know what it is about! A title  What was changed to find out its effect? A variable What was measured to find out the effect? Another variable  What are the units? (cm/km etc.)

Graphing The thing that was changed (independent variable) to find out its effect has been put on a horizontal axis. (X axis) The thing that was measured (dependent variable)to find out the effect has been put on a vertical axis (Y axis) Temp ( o C) Volume of gas (cm 3 )

Drawing Graphs  This activity requires you to match the graph with the data it represents.  You can ring the data in a colour coordinated way  Or put corresponding letters/numbers for a table and the graph representing the data.

Mass of paper clips picked up (g) Number of turnsExperiment 1Experiment 2Experiment 3Average mass (g)

Distance from power station pH of water sample sample 1sample 2sample 3Average pH

Resistance (ohms) length of wireTest 1Test 2 Average resistance (Ω)

Temp ( o C)Volume of gas (cm 3 ) Drawing Graphs Use the data in the table on the left to produce a graph.  What are you going to put on you y axis?  Which data will you put on the x axis? Hint! What are you changing?  Make sure you remember the rules for graph drawing!

David’s Analysis: “The volume of gas went up and then dropped at 25 O C “  Based on David’s graph, what information has he missed out?  Does the volume of gas rise again?  In your pairs use the yellow sheet provided to improve upon David’s analysis

Task  You will have in front of you two yellow sheets. One sheet has some graphs drawn whilst the other has some descriptive words.  Whilst one of you (student a) studies the pattern on the graphs the other one (student b) is to use the descriptive words to describe a graph. Student a’s job is to work out which graph is being described.  You then swap roles and have two goes each.

Describing Graphs a) b) c) d) e) f) vertical axis (y axis) Horizontal axis (x axis) Origin

Describing Graphs Vocabulary list Adjectives (words used to describe something) Slightly, suddenly, sharply, steeply, gradually, slowly, gently, steadily, a little, a lot. Comparative Adjectives (descriptive words that are used to compare) Bigger, larger, smaller, lower, higher, shorter, taller, steeper, steadier, colder, warmer, lighter, darker, faster, slower. When a line moves upIncreased, rose up, went up, grew, incline. When a line moves downDecreased, fell, went down, dropped, declined. When there is no movementRemained steady, constant, unchanged, stable. When the line reaches the top and stops or hits the bottom and stops Peaked, reached the highest point, reached the lowest t point, reached the bottom, bottomed out, reached the lowest/highest level. Originally produced by S. jones SLCEE