given 9.5 g of KBr (molar mass is 119 g/mol) dissolved in water to make a 175 mL solution, what would the molarity be?
mols KBar = grams/molar mass
M = mols/L soln.
thanks!
To find the molarity (M) of a solution, you need to know the moles of solute (KBr) and the volume of the solution (in liters).
First, let's find the number of moles of KBr in 9.5 g. We can do this using the formula:
moles = mass / molar mass
moles = 9.5 g / 119 g/mol
moles = 0.0798 mol (rounded to four decimal places)
Next, we convert the volume of the solution from milliliters (mL) to liters (L). Since there are 1000 mL in 1 L:
volume = 175 mL / 1000
volume = 0.175 L
Now that we have the moles of KBr and the volume of the solution in liters, we can calculate the molarity:
M = moles / volume
M = 0.0798 mol / 0.175 L
M = 0.455 M (rounded to three decimal places)
Therefore, the molarity of the KBr solution is 0.455 M (mol/L).