Answer: The solubility of NaNO3 (sodium nitrate) in water increases as temperature increases. Therefore, we need to know the solubility of NaNO3 at different temperatures to determine the temperature at which 140 g of NaNO3 can be fully dissolved in water.
According to the solubility curve for NaNO3, the maximum solubility of NaNO3 in water is approximately 88 g per 100 g of water at 80°C. This means that at 80°C, we can dissolve 88 g of NaNO3 in 100 g of water to make a saturated solution.
To fully dissolve 140 g of NaNO3, we need to dissolve it in a sufficient amount of water that can dissolve at least 140 g of NaNO3. Using a proportion, we can calculate the amount of water required to dissolve 140 g of NaNO3 at 80°C:
88 g NaNO3 / 100 g water = 140 g NaNO3 / x g water
Solving for x, we get:
x = 159.1 g water
This means that at 80°C, we need to dissolve 140 g of NaNO3 in at least 159.1 g of water to make a saturated solution, in which all of the NaNO3 will be dissolved.
Therefore, the temperature at which 140 g of NaNO3 can be fully dissolved in water is approximately 80°C.
Step-by-step explanation: