APPARATUS REQUIRED:
Conical flask / Beaker, Weighing balance, Evaporating dish,Pipette.
CHEMICAL REQUIRED:
Barium chloride, Water
THEORY:
Solubility is often expressed as the number of milliliters of solvent needed to dissolve 1 gram of solute to make a saturated solution. Solubility refers to the ability of a substance to dissolve in a given amount of solvent to form a saturated solution for solids, solubility is often described in terms of how much of the solid can dissolve in a specific volume of solvent, such as water Solubility serves as a measure of how much of a substance can dissolve in a specific amount of solvent to form a saturated solution, providing valuable information about the substance’s behavior in solution.
Term | Parts of solvent required to dissolve 1 part of solute |
very soluble | less than 1 part |
freely soluble | 1 to 10 parts |
Soluble | 10 to 30 parts |
Sparingly soluble | 30 to 100 parts |
Slightly soluble | 100 to 1000 parts |
very slightly soluble | 1000 to 10,000 parts |
Practically insoluble | More than 10,000 parts |
PROCEDURE:
An increasing amount of barium chloride was added to about 50 ml water in a conical flask/beaker with shaking/stirring until the solution was saturated and a part of solid was left undissolved (around 20gm barium chloride was required). The solution was filtered and 10ml of the filtrate was pipetted out into a tared (preweighed) evaporating dish. The dish containing 10 ml filtrate was weighed. The filtrate was evaporated to dryness & further dried at about 100°C in an oven. Then it was cooled and weighed. Drying was continued till a constant weight was obtained.
OBSERVATION:
Room temperature: °C
i) Weight of empty dish (W₁) = 85.01gm
ii) Weight of dish + 10ml solution (W2) = 97.55gm
iii) Weight of dish + dry solution in gm/powder remaining after drying (W3) = 88.44gm
CALCULATION:
weight of solute in 10 ml solution = W3-W1
= 88.44-85.01
= 3.43gm
weight of solvent in 10 ml solution = W2-W3
= 97.55-88.44
= 9.11gm
volume of solvent in ml = weight of solvent/density of solvent (water)
= 9.11/1
= 9.11 ml
Solubility is the parts of solvent required for 1 part of solute.
3.43gm of solute requires 9.11 ml of water
1gm of solute requires 9.71/3.43 ml of water
i.e. 2.65 ml of water
RESULT
The solubility of barium chloride in water at room tempeture is 1 in 2.65ml. Hence, the given sample of barium chloride is freely soluble in water.