Potassium bromide has a solubility of 80g/100ml of H20 at 50º C. A saturated solution would be equivalent to a ____________-molar solution?
80 g KBr is how many moles? moles = grams/molar mass.
M = moles/0.1L = ??
To find the molarity of a solution, we need to know the number of moles of solute dissolved in a given volume of solvent. In this case, we are given the solubility of potassium bromide (KBr) as 80 g/100 ml of water at 50º C.
To convert the given solubility from grams to moles, we need to know the molar mass of KBr. The molar mass of KBr is calculated by adding the atomic masses of potassium (K) and bromine (Br). The atomic mass of K is 39.10 g/mol, and the atomic mass of Br is 79.90 g/mol.
So, the molar mass of KBr is:
Molar mass of KBr = (39.10 g/mol) + (79.90 g/mol) = 119.00 g/mol
Next, we can calculate the number of moles of KBr in 80 g of KBr:
Number of moles = Mass / Molar mass = 80 g / 119.00 g/mol
Using this calculation, we find that there are approximately 0.67 moles of KBr in 80 g.
Now, let's consider the volume of the solution. A saturated solution contains the maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature. In this case, the solubility is given as 80 g/100 ml of water. Therefore, we have 80 g of KBr dissolved in 100 ml of water.
To find the molarity, we need to convert the volume from milliliters (ml) to liters (L). There are 1000 milliliters in 1 liter, so:
Volume in liters = 100 ml / 1000 = 0.1 L
Now we can calculate the molarity of the solution by dividing the number of moles of KBr by the volume in liters:
Molarity = Number of moles / Volume in liters = 0.67 moles / 0.1 L
Using this calculation, we find that the molarity of the saturated solution is approximately 6.7 M (mol/L).
Therefore, a saturated solution of potassium bromide would be equivalent to a 6.7-molar solution.