Question

a student was performing a spectrophotometric analysis of a colored compound. their data is given in the table below and in the corresponding graph. choose the appropriate axes titles, units, and sig figs. hint: think about what variable is under the experimenters control in this lab. absorbance molar concentration 0.062 4.0×10⁻⁴ 0.126 8.0×10⁻⁴ 0.183 1.2×10⁻³ 0.459 2.9×10⁻³ 0.631 4.1×10⁻³ y = 154.96x + 0.0009 r² = 0.9995 y - axis title: select y - axis units: select y - axis number of sig figs: select x - axis title: select x - axis units: select x - axis number of sig figs: select

Explanation:

Step1: Identify independent variable

The experimenter controls the molar - concentration of the colored compound. So, molar concentration is the independent variable and should be on the x - axis. Absorbance is the dependent variable and should be on the y - axis.

Step2: Determine y - axis details

The y - axis represents absorbance. The unit of absorbance is dimensionless. The values of absorbance in the data have 3 significant figures.

Step3: Determine x - axis details

The x - axis represents molar concentration. The unit of molar concentration is molar (M). The values of molar concentration in the data have 2 significant figures.

Answer:

y - axis title: Absorbance
y - axis units: None (dimensionless)
y - axis number of sig figs: 3
x - axis title: Molar Concentration
x - axis units: M (molar)
x - axis number of sig figs: 2