Final answer:
Without a solubility curve or data point for 40°C, we cannot definitively answer how much potassium nitrate can dissolve in 300 g of water at that temperature. Solubility is proportional to the amount of solvent, so with the correct data, it would be a straightforward calculation.
Step-by-step explanation:
To determine how much potassium nitrate (KNO₃) can be dissolved in 300 g of water at 40°C, we need to refer to a solubility curve specific to KNO₃. Solubility curves typically provide the solubility of a solute in 100 g of water at various temperatures. As the scenario given in the question closely relates to the behavior described by solubility curves, we would extrapolate from the given data points.
Unfortunately, without the actual solubility curve or data table provided for 40°C, we can only describe the process and cannot provide an exact figure for the solubility of KNO₃ at 40°C in 300 g of water.
If, hypothetically, the solubility of KNO₃ at 40°C were provided as X g per 100 g of water, then to find the solubility in 300 g of water, we would perform the following calculation:
Amount of KNO₃ that can dissolve in 300 g of water = (X g / 100 g of water) × 300 g of water
This is done because solubility is directly proportional to the amount of solvent, assuming the system remains unsaturated. If the provided solubility data indicates that 200 g of KNO₃ is soluble in 1000 g of water at 40°C, for example, we could scale that number down to 200 g / (1000 g / 300 g) = 60 g for 300 g of water.
But without the specific solubility value at 40°C, we cannot confidently select an answer from the provided options (A, B, C, or D).