If the solubility of KNO\(_3\) at 30\(^0\)C is 3.10 mol/dm\(^3\) a solution containing 303g/dm\(^3\) KNO\(_3\) is likely to be
- saturated
-
unsaturated
- supersaturated
- at saturation point
The correct answer is: B
Explanation
To determine whether the solution is saturated or unsaturated, we need to compare the actual concentration of the solution (g/dm³) with the solubility of KNO₃ at the same temperature (mol/dm³).
First, let’s convert the given mass concentration to mol/dm³ using the molar mass of KNO₃.
Molar mass of KNO₃ = (39 g/mol) + (14 g/mol) + (3 x 16 g/mol) = 101g/mol
Molar Concentration (mol/dm³)\} = \(\frac{mass concentration}{Molar mass}\)
= \(\frac{303}{101}\)
= 3.00moldm\(^3\)
Comparing, the concentration (3.00 mol/dm³) with the solubility of KNO₃ at 30°C (3.10 mol/dm³).
If the concentration is less than the solubility, the solution is unsaturated because more solute can dissolve. If the concentration is equal to the solubility, the solution is saturated because no more solute can dissolve. If the concentration is greater than the solubility, the solution is supersaturated, but this case is not relevant to our comparison.
In this case, the concentration (3.00mol/dm³) is less than the solubility (3.10 mol/dm³). Therefore, the solution is unsaturated at 30°C because more KNO₃ can dissolve in the solution.
There is an explanation video available .