Making a solution at 100•C
What would be the smallest volume of water needed to dissolve 12.0g of KNO3 at 100•C
To determine the smallest volume of water needed to dissolve 12.0g of KNO3 at 100°C, we need to consider the solubility of KNO3 at this temperature. The solubility of KNO3 generally increases with temperature.
To find the solubility of KNO3 at 100°C, we can consult a solubility table or use a reliable source such as the CRC Handbook of Chemistry and Physics.
According to a reliable source, the solubility of KNO3 at 100°C is approximately 247 grams per 100 grams of water (g/100g H2O). This means that at 100°C, 100 grams of water can dissolve 247 grams of KNO3.
To find the volume of water required to dissolve 12.0g of KNO3 at 100°C, we need to calculate the necessary mass of water based on the solubility.
First, convert the given mass of KNO3 to grams:
12.0g of KNO3
Next, use the solubility ratio to calculate the mass of water needed:
Mass of water = (mass of KNO3 / solubility ratio)
Mass of water = (12.0g / 247g) * 100g = 4.86g
Now that we have the mass of water required, we can convert it to volume.
To convert mass to volume, we need to know the density of water at the given temperature. At 100°C, the density of water is relatively close to 0.998 g/mL.
Convert the mass of water to volume:
Volume of water = (mass of water / density of water)
Volume of water = 4.86g / 0.998g/mL ≈ 4.87mL
Therefore, the smallest volume of water needed to dissolve 12.0g of KNO3 at 100°C is approximately 4.87 mL.