(a) Differentiate between a saturated and an unsaturated solution. How will you test whether a given solution is saturated or not?
(b) How would you prepare a saturated solution of sodium chloride in water at 25∘C ? What will happen if this solution is cooled to 10∘C ?
(a) Differentiate between a saturated and an unsaturated solution. How will you test whether a given solution is saturated or not?
(b) How would you prepare a saturated solution of sodium chloride in water at 25∘C ? What will happen if this solution is cooled to 10∘C ?
(a) Saturated solution: A solution in which no more of the solid (solute) can be dissolved at a given temperature and pressure is called a saturated solution.
Unsaturated solution: A solution in which more of the solid can be dissolved at the given temperature and pressure is called an unsaturated solution.
When referring to solutions, there are three degrees of saturation—unsaturated, saturated, and supersaturated. If a solution is unsaturated, the solvent is capable of dissolving more solute. When the solution is saturated, the solvent has dissolved the maximum amount of solute that it can at the given temperature. Raising the temperature of a solution may even turn a saturated solution into an unsaturated one. Or, lowering the temperature of a solution may change it from unsaturated to saturated.
(b) To prepare the saturated solution of NaCl at 25∘C , take a measured volume of water (say 100 ml.) in a beaker and warm it up to 25∘C . Then add NaCl pinch by pinch at constant stirring and observe the point when no more NaCl is dissolving in water. At that point, the added pinch of NaCl will appear at the bottom of the beaker and your saturated solution is prepared. On cooling, crystals (particles) of NaCl separate from the solution. This separation technique is known as crystallization.
(a) Saturated solution: A solution in which no more of the solid (solute) can be dissolved at a given temperature and pressure is called a saturated solution.
Unsaturated solution: A solution in which more of the solid can be dissolved at the given temperature and pressure is called an unsaturated solution.
When referring to solutions, there are three degrees of saturation—unsaturated, saturated, and supersaturated. If a solution is unsaturated, the solvent is capable of dissolving more solute. When the solution is saturated, the solvent has dissolved the maximum amount of solute that it can at the given temperature. Raising the temperature of a solution may even turn a saturated solution into an unsaturated one. Or, lowering the temperature of a solution may change it from unsaturated to saturated.
(b) To prepare the saturated solution of NaCl at 25∘C , take a measured volume of water (say 100 ml.) in a beaker and warm it up to 25∘C . Then add NaCl pinch by pinch at constant stirring and observe the point when no more NaCl is dissolving in water. At that point, the added pinch of NaCl will appear at the bottom of the beaker and your saturated solution is prepared. On cooling, crystals (particles) of NaCl separate from the solution. This separation technique is known as crystallization.
