 # When the solubility of a solute is s g at a certain temperature, the mass fraction of solute in saturated solution at that temperature () A. Greater than S% B. Equal to S% C. Less than S% D. Unable to judge

## When the solubility of a solute is s g at a certain temperature, the mass fraction of solute in saturated solution at that temperature () A. Greater than S% B. Equal to S% C. Less than S% D. Unable to judge

Solubility is the saturated solution of S. according to the concept of solubility, s is the mass of solute dissolved when saturation is reached in 100g solvent. Assuming that the solute mass fraction of saturated solution is a%, it means that 100g saturated solution contains Ag solute, that is, some solvents in this solution are less than 100g, the more solvents are at the same temperature, the more solutes are dissolved, so the value of S is greater than the value of A
So choose C

### When the mass fraction of solute in m g of a saturated solution is a% at t ° C, the solubility of the substance at temperature is?

The mass of a solid substance dissolved when it reaches saturation in 100g solvent at a certain temperature is called the solubility of this substance in this solvent
Solute mass = m * a%, solvent mass = m * (1-A%), solubility of the substance at t temperature = 100 * m * a% / m * (1-A%) = 100 * a% / (1-A%)

### At a certain temperature, the solubility of NaC1 is 36g. Calculate 2010g. The mass fraction of solute in the saturated solution at this temperature is% (accurate to 0.1%; calculation process is required)

2010g the mass fraction of solute in saturated solution at this temperature is 36 / 136 = 26.5%

### It is known that at 20 ℃, the solubility of NaCl is 36g. It is said that at 20 ℃, the mass fraction of solute in NaCl saturated solution is 36%. Is this statement right? It is known that at 20 ℃, the solubility of NaCl is 36g. Is it right to say that "at 20 ℃, the mass fraction of solute in NaCl saturated solution is 36%?"? Why?

No, it is known that at 20 ℃, the solubility of NaCl is 36 g. 36 g of sodium chloride is dissolved in 100 g of water, and the mass fraction of solute in the solution = 36 (36 + 100) = 26.4%

### If the mass fraction of solute in the saturated solution of potassium nitrate at T1 ℃ is 20%, the solubility of potassium nitrate at T1 ℃ is () g. the solubility of potassium nitrate at T2 ℃ is known Add the above: it is 3 times the solubility at T1 ℃, and the mass fraction of solute in potassium nitrate saturated solution at T2 ℃ is ()%

Potassium nitrate water
20 80
S 100
Solubility s = 25g
S2=75g
75/(75+100)=42.9%

### A substance can react with water. Now a small amount of this substance is added to saturated lime water, and the solution becomes turbid. The correct description is (a) A. The mass of solute must decrease after the reaction. B. the mass fraction of solute in the solution must remain unchanged before and after the reaction Ask why B is wrong?

If a substance can react with water, the water in the original solution is reduced
The original solution is a saturated solution. When there is less water, solutes naturally precipitate, so the mass of solutes must be reduced after the reaction
When the substance reacts with water, the product may be dissolved in the solution, so the solute mass fraction may change