Interpretation:
The function of a control in an experiment needs to be explained.
Concept introduction:
A set of controlled observations done to test the hypothesis is known as an experiment.

Answer to Problem 40A
Control is the standard for comparison. It is a variable that is constant, thus it is not considered as a variable.
Explanation of Solution
An experiment is set up carefully in order to change a variable at a time. A variable is a quantity or condition that may have one or more value. There are two types of variables, independent and dependent variable. An independent variable can be changed by the performer whereas dependent variable changes in response to a change in independent variable.
One of the factors is control that is an essential part of the experiment. A control is the standard for comparison. It is an observation that is designed to reduce the effects of variable except other than the independent variable. Due to control, the reliability of the results increases by comparing the control measurements and the other measurements.
Control is an important factor of an experiment. It is designed to reduce the effects of a variable other than the independent variable.
Chapter 1 Solutions
Chemistry: Matter and Change
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