Describing graphs

What should you include when describing a graph?

Mention the overall trend, specific data points, shape of the graph, and any anomalies.

How to describe a graph that goes up

"As [independent variable] increases, [dependent variable] increases" – a positive correlation.

How to describe a graph that goes down

"As [independent variable] increases, [dependent variable] decreases" – a negative correlation.

How to describe a flat graph

"The [dependent variable] stays constant as [independent variable] increases" – no change.

What does a curve that levels off mean?

It suggests the reaction is slowing down or reaching equilibrium/completion.

What is a steep gradient on a graph?

A fast rate of change – the dependent variable is changing quickly.

What is a shallow gradient on a graph?

A slow rate of change – the dependent variable is changing slowly.

How to identify the rate of reaction from a graph

Look at the steepness of the slope – steeper = faster rate.

How to describe an anomalous point on a graph

"This point does not follow the general trend; it may be an anomaly."

How to compare two lines on the same graph

Compare their gradients (steepness), where they start, and where they level off.

How to describe the shape of a temperature vs time graph when heating a substance

Line rises steadily (heating), flattens during melting/boiling (no temperature change while changing state), then rises again.

How to describe a graph showing mass of product over time

Mass increases at first, then levels off as the reaction completes.

How to describe a graph showing gas volume over time

Gas volume increases, then levels off when all reactants are used.

How to interpret a line that goes through the origin

Directly proportional relationship – doubling one doubles the other.

How to describe fluctuations in a graph

Use terms like “increases then decreases”, “peaks at”, or “drops suddenly”.