11.2 Graphical Techniques

When plotting a graph to determine the relationship between two variables, which of the following is the most important factor to consider?

A. Colour of the graph

B. Size of the graph paper

C. Proper scaling and labelling of axes

D. The brand of the pen used

Which type of graph is most suitable for representing categorical data?

A. Scatter plot

B. Line graph

C. Bar graph

D. Pie chart

In the context of an experiment, what does the gradient of a graph typically represent?

A. The initial value of the dependent variable

B. The change in the independent variable per unit change in the dependent variable

C. The total change in the dependent variable

D. The average value of the independent variable

If a graph of volume (V) against temperature (T) for a gas gives a straight line with a negative y-intercept, what does the y-intercept represent?

A. Absolute zero in Celsius

B. Absolute zero in Kelvin

C. Boiling point of the gas

D. Melting point of the gas

Why is it important to include error bars in a graph?

A. To make the graph look more professional

B. To indicate the precision of the data

C. To show the range of possible values for each data point

D. To indicate the accuracy of the data

a) Describe the importance of proper scaling and labelling of axes when plotting a graph in a chemistry experiment. [3]

b) Explain the difference between a scatter plot and a bar graph, and provide a scenario in a chemistry context where each would be most appropriate. [3]

a) Define the terms "gradient" and "y-intercept" in the context of a linear graph. [2]

b) How can the gradient and y-intercept of a graph be used to make predictions about an experiment? Provide an example. [3]

a) What is the significance of including units and error bars in a graph? [3]

b) Describe a scenario in a chemistry experiment where transforming non-linear data into a linear form would be beneficial. [2]

a) Explain the difference between systematic and random errors in the context of a chemistry experiment. [3]

b) How can systematic errors be identified and corrected? [3]

c) Describe a scenario where random errors might be more prevalent and suggest ways to minimise them. [3]

a) What is the importance of choosing the appropriate graph type in representing data from a chemistry experiment? [3]

b) Describe a situation where a bar graph would be more appropriate than a scatter plot. [2]

c) How does the interpretation of the gradient differ between a distance-time graph and a concentration-time graph in a reaction experiment? [3]