what mass of potassium hydroxide is required to produce 2.00L of a solution mthat has a pOH of 4.5?
pOH = 4.5. Convert to (OH^-) in units of molarity.
Then M = moles/L.
Substitute M and L, solve for moles.
Then moles = grams/molar mass. Solve for grams.
To determine the mass of potassium hydroxide (KOH) required, we need to follow a series of steps. Let's break it down:
Step 1: Understand the problem.
We aim to find the mass of KOH required to produce a 2.00L solution with a pOH of 4.5.
Step 2: Gather the necessary information.
To solve this problem, we need a few pieces of data:
- The equation for the dissociation of potassium hydroxide: KOH(s) → K⁺(aq) + OH⁻(aq)
- The relationship between pOH, pH, and pKw (the ion product of water): pOH + pH = 14 and pKw = 14
- The definition of pOH: pOH = -log[OH⁻]
Step 3: Calculate the concentration of OH⁻ ions.
We know that pOH = -log[OH⁻]. Rearranging the equation, we get [OH⁻] = 10^(-pOH). Plugging in the value of pOH = 4.5, we find [OH⁻] = 10^(-4.5).
Step 4: Determine the moles of OH⁻.
To find the moles of OH⁻, we need to multiply the concentration ([OH⁻]) by the volume of the solution. Since we have 2.00L of solution, we can multiply that by [OH⁻] to find the moles of OH⁻.
moles of OH⁻ = [OH⁻] × volume of solution
Step 5: Calculate the moles of KOH.
Referencing the balanced chemical equation for the dissociation of KOH, we know that one mole of KOH produces one mole of OH⁻ ions. Therefore, the moles of KOH will be the same as the moles of OH⁻.
moles of KOH = moles of OH⁻
Step 6: Convert moles to grams.
To convert moles of KOH to grams, we will multiply the moles by the molar mass of KOH (which can be found in the periodic table).
mass of KOH = moles of KOH × molar mass of KOH
By following these steps, you will be able to calculate the mass of potassium hydroxide required to produce a solution with a pOH of 4.5.