Final answer:
To find the mass of glucose required to lower the freezing point to -5.1°C, calculate the freezing point depression, determine the molality, find the moles of glucose, and then convert these moles to mass. As the freezing point depression constant for water is not provided, a numerical answer cannot be given.
Step-by-step explanation:
To determine the mass of glucose (C6H12O6) that should be dissolved in water to lower the freezing point to -5.1°C, the following steps should be taken:
- Calculate the freezing point depression (ΔTf) using the formula ΔTf = i * Kf * m, where i is the van't Hoff factor (which is 1 for glucose, a nonelectrolyte), Kf is the freezing point depression constant for water, and m is the molality of the solution.
- Determine the molality (m) by rearranging the formula to m = ΔTf / (i*Kf).
- Find the moles of glucose needed using the molality formula, m = moles of solute / kg of solvent.
- Convert the moles of glucose to mass using the molar mass of glucose.
However, without the freezing point depression constant (Kf) for water, we cannot provide a numerical answer to this question.