If 5.6 grams of potassium hydroxide is added to enough water to make 950 ml of solution, what is the concentration of the potassium?
Well, to be a smart aleck, I would say it's 5.6g/950 mL since you didn' specify %, M, m, or what.
If you want molarity, M, then
mols KOH = grams/molar mass
and M = mols/L solution.
To find the concentration of potassium in the solution, we need to calculate the molarity of the potassium hydroxide (KOH) solution.
First, we need to convert the mass of potassium hydroxide (KOH) to moles. The molar mass of KOH is the sum of the atomic masses of potassium (K), oxygen (O), and hydrogen (H). The atomic masses are approximately:
Potassium (K): 39.10 grams/mol
Oxygen (O): 16.00 grams/mol
Hydrogen (H): 1.01 grams/mol
We can use these atomic masses to find the molar mass of KOH:
Molar mass of KOH = (39.10 g/mol) + (16.00 g/mol) + (1.01 g/mol) = 56.11 g/mol
To determine the number of moles of KOH, we divide the given mass of KOH (5.6 grams) by its molar mass (56.11 g/mol):
Number of moles = Mass / Molar mass
Number of moles = 5.6 g / 56.11 g/mol
Now, let's calculate the molarity of the solution. The molarity (M) is defined as the number of moles of solute (KOH) divided by the volume of the solution in liters (L):
Molarity (M) = Moles of solute / Volume of solution (L)
Since the volume of the solution is given in milliliters (ml), we need to convert it to liters by dividing by 1000:
Volume of solution (L) = 950 ml / 1000
Now, we can substitute the values into the equation:
Molarity (M) = (5.6 g / 56.11 g/mol) / (950 ml / 1000)
Simplifying further:
Molarity (M) = (5.6 / 56.11) / (0.950)
Calculating:
Molarity (M) = 0.1 M
Therefore, the concentration of potassium in the solution is 0.1 M.