Final answer:
The solubility of caffeine in water increases with temperature, but specific values require experimental data. The molarity of caffeine in a coffee can be determined by dividing the mass of caffeine by its molar mass and the volume of the solution in liters. Solubility at a specific elevation is not provided and cannot be determined with the information given.
Step-by-step explanation:
The solubility of caffeine in water can vary based on temperature, but specific values at 25 °C and 80 °C are not directly provided in the reference materials. However, understanding how solubility generally behaves with temperature can help. Typically, for many solids like caffeine, solubility will increase with temperature. The third condition mentioned in the question, '670 m,' does not correspond with a temperature or pressure setting and therefore cannot be used to determine solubility.
Now, to calculate the molarity of a caffeine solution, you can use the given data from Exercise 9.6.5. Given a 350 mL cup of coffee contains 0.150 g of caffeine (C8H10N4O2), its molarity is calculated as follows:
- Convert the mass of caffeine to moles by dividing by the molar mass (194.19 g/mol for caffeine): moles = 0.150 g / 194.19 g/mol.
- Convert the volume of coffee from mL to L by dividing by 1000: volume = 350 mL / 1000.
- Calculate the molarity (moles per liter) using the formula: molarity = moles / volume.
For Example 16.2.2, regarding CaF2, the solubility is used to calculate the solubility product constant (Ksp), which can be a bit more complex as it involves the stoichiometry of the dissociation in water. Reference to the solubility product constant or Henry's law is not directly applicable to the solubility of caffeine.