For this experiment, which of the following would be correct?

Question

A person wanted to determine the average pH of soft drinks.

The pH is the IV.

Water is used as the control.

The volume of the soda needs to be constant.

The type of soda would be placed on the Y-axis of the graph.

Answer 1

The type of soda is the independent variable and, as such, goes on the Y axis of the graph (horizontal).  The pH is the dependent variable and goes on the X axis (vertical) of the graph.