If 20g of NaCl was used to form a 250cm3 of saturated solution of NaCl at 25oC. Calculate the solubility of the salt in mol/dm3 at that temperature. (Relative density of solution-1).
To calculate the solubility of NaCl in mol/dm³ at 25°C, we need to use the given information:
Mass of NaCl = 20g
Volume of solution = 250 cm³
Firstly, we need to convert the volume of the solution from cm³ to dm³. Since 1 dm³ is equal to 1000 cm³, we can calculate:
Volume of solution (in dm³) = 250 cm³ / 1000 = 0.25 dm³
Next, we can use the definition of molarity (M) to calculate the solubility. Molarity is defined as the number of moles of solute (NaCl) per liter of solution.
Molarity (M) = moles of solute (NaCl) / volume of solution (in liters)
We can calculate the moles of NaCl using its molar mass. The molar mass of NaCl is 58.44 g/mol.
Moles of NaCl = Mass of NaCl / Molar mass of NaCl = 20g / 58.44 g/mol
Now we can substitute the values into the equation for molarity:
M = (20g / 58.44 g/mol) / 0.25 dm³
Simplifying this equation gives us:
M = (20/58.44) / 0.25
By evaluating this expression, we find:
M = 0.137 mol/dm³
Therefore, the solubility of NaCl in mol/dm³ at 25°C is 0.137 mol/dm³.
To calculate the solubility of NaCl in mol/dm3, you need to determine the number of moles of NaCl dissolved in the 250 cm3 of saturated solution.
First, convert the mass of NaCl from grams to moles using the formula:
Number of moles = Mass / Molar mass
The molar mass of NaCl (sodium chloride) is 58.44 g/mol.
Number of moles of NaCl = 20 g / 58.44 g/mol ≈ 0.342 mol
Next, calculate the volume in dm3 (cubic decimeters) using the given volume of 250 cm3:
Volume in dm3 = 250 cm3 / 1000 cm3/dm3 = 0.25 dm3
Finally, calculate the solubility of NaCl in mol/dm3 by dividing the number of moles by the volume in dm3:
Solubility = Number of moles / Volume
Solubility = 0.342 mol / 0.25 dm3 ≈ 1.368 mol/dm3
Therefore, the solubility of NaCl in the saturated solution is approximately 1.368 mol/dm3 at 25°C.