Physical and analytical chemistry

[rngz]

at 20 degree celcius, the solubility of a solid substance x in water is 42g/L. There are 3 solutions containing x kept at this temperature: S1 5.1g/L, S2 contains 39g/L, and S3 contains 57g/L.

if we want to make S1 saturated with x, is it possible that we can add an equal volume of S2 and S1 because the overall concentration will become about 44g/L. or is it we must add more S2? what equation should I use?

 

[chemisttree]

The answer is no. You cannot combine dilute solutions in any proportion to get a more concentrated one. You must use S3.

 

[oswaler]

I would like to clarify that the solubility of a substance in water is affected by various factors such as temperature, pressure, and the presence of other solutes. Therefore, the solubility of substance x in water at 20 degrees Celsius may not be the same under different conditions.

Based on the information provided, it seems that substance x has a solubility of 42g/L at 20 degrees Celsius. This means that at this temperature, 42 grams of substance x can dissolve in 1 liter of water. The three solutions mentioned, S1, S2, and S3, have different concentrations of substance x, and it is possible that they were prepared under different conditions.

To make S1 saturated with substance x, it would be helpful to know the volume of S1 and the amount of substance x that is already dissolved in it. If we assume that the volume of S1 is 1 liter and it currently contains 5.1 grams of substance x, then adding an equal volume of S2 (1 liter) would indeed result in a concentration of approximately 44g/L. This is because S2 contains 39 grams of substance x in 1 liter of solution, and when combined with S1, the total amount of substance x would be 44.1 grams in 2 liters of solution.

However, if the volume of S1 is less than 1 liter or if it already contains more than 5.1 grams of substance x, then adding an equal volume of S2 may not result in a saturated solution. In this case, more S2 would need to be added to reach the desired concentration of 42g/L.

To determine the exact amount of S2 needed to make S1 saturated, we can use the equation for molarity (M) which is M = moles of solute/volume of solution (in liters). By rearranging this equation, we can calculate the moles of substance x needed in S1 to reach a concentration of 42g/L, and then use this value to determine the amount of S2 required.

In conclusion, it is possible to make S1 saturated with substance x by adding an equal volume of S2, but the exact amount of S2 needed may vary depending on the initial concentration of substance x in S1. The equation for molarity can be used to determine the amount of S2 required to reach a concentration of 42