Final answer:
At 70°C, the mass of KNO3 that will dissolve in 100mL of water can be calculated using the solubility data. The solubility of KNO3 in water at 70°C is approximately 155 grams per 100 mL of water.
Step-by-step explanation:
The solubility of a substance in a solvent, such as water, changes with temperature. In this case, at 70°C, the solubility of KNO3 in water is known to be 155 grams per 100 mL of water. This means that at this temperature, 100mL of water can dissolve up to 155 grams of KNO3.
Solubility is often expressed as grams of solute per 100 mL of solvent. In the given scenario, the solubility data specifically states that 155 grams of KNO3 can dissolve in 100mL of water at 70°C. Therefore, if 100mL of water is available, it can dissolve a maximum of 155 grams of KNO3 at this temperature.
It's essential to note that the solubility of substances is influenced by temperature changes. As temperature increases, the solubility of many solids in liquids also increases. Hence, knowing the solubility data at a particular temperature is crucial for determining the maximum amount of solute that can dissolve in a given volume of solvent.