In an experiment determining the effect of a nonvolatile solute on boiling point, what is the independent variable?

In an experiment designed to explore the effect of a nonvolatile solute on the boiling point, the independent variable is the factor that is deliberately manipulated to observe its impact on the dependent variable. In this context, adding different amounts of a nonvolatile solute, such as salt, directly affects the boiling point of the solvent, typically water.

The nonvolatile solute influences boiling point elevation, which is a colligative property. By varying the amount of salt added, the researcher can determine how changes in solute concentration affect the boiling point. This direct manipulation allows the researcher to analyze the relationship between the concentration of the solute and the boiling point, culminating in a clearer understanding of how nonvolatile solutes alter physical properties of the solvent.

The other choices represent variables that would either remain constant or change as a consequence of the manipulation of the independent variable. For instance, the temperature of the water is the dependent variable measured in response to the solute, the size of the container is typically controlled to ensure consistent conditions, and the time of heating would also remain constant to allow for fair comparison of results. Thus, the amount of salt added is correctly identified as the independent variable.