Chemistry
A solution was prepared by dissolving 0.62 g of KOH(s) to form 500 mL of solution.
The pH of the potassium hydroxide solution is
The pH of a solution of KOH can be calculated using the formula:
pH = -log10([OH-])
First, we need to find the concentration of hydroxide ions ([OH-]) in the solution. We can do this by first finding the number of moles of KOH and then dividing by the volume of the solution in liters.
Molar mass of KOH = 39.10 g/mol + 16.00 g/mol + 1.01 g/mol = 56.11 g/mol
Number of moles of KOH = mass of KOH / molar mass of KOH = 0.62 g / 56.11 g/mol = 0.011 mol
Volume of the solution in liters = 500 mL / 1000 mL/L = 0.5 L
Concentration of hydroxide ions = number of moles of KOH / volume of the solution = 0.011 mol / 0.5 L = 0.022 M
Now, we can calculate the pH using the formula:
pH = -log10(0.022) ≈ 1.66
Therefore, the pH of the potassium hydroxide solution is approximately 1.66.
are you sure?
I apologize, there was a mistake in my previous response. Since KOH is a strong base, it dissociates completely in water, producing an equal concentration of hydroxide ions (OH-). Therefore, the concentration of hydroxide ions in the solution is equal to the concentration of KOH.
Concentration of KOH = 0.62 g / 56.11 g/mol / 0.5 L = 0.022 M
pH = -log10(0.022) ≈ 1.66
Therefore, the correct pH of the potassium hydroxide solution is approximately 1.66.
To determine the pH of the potassium hydroxide (KOH) solution, we need to understand that KOH is a strong base. When a strong base dissolves in water, it completely dissociates into its constituent ions - in this case, potassium (K⁺) and hydroxide (OH⁻) ions.
Since the hydroxide ions are responsible for the basicity of the solution, we can use the concentration of hydroxide ions to find the pH. The formula to calculate the hydroxide ion concentration ([OH⁻]) is:
[OH⁻] = moles of KOH / volume of solution
First, we need to determine the moles of KOH using its molar mass. The molar mass of potassium (K) is approximately 39.10 g/mol, and the molar mass of hydroxide (OH) is approximately 17.01 g/mol. So, the molar mass of KOH is:
Molar mass of KOH = molar mass of K + molar mass of OH
= 39.10 g/mol + 17.01 g/mol
= 56.11 g/mol
Now, we can calculate the moles of KOH using the given mass. Since 0.62 g of KOH was dissolved, the moles of KOH can be found using the formula:
moles of KOH = mass of KOH / molar mass of KOH
= 0.62 g / 56.11 g/mol
Next, we need to determine the volume of the solution. It is given that the solution was prepared by dissolving the KOH in 500 mL of solution.
Now, we can substitute the values into the equation to calculate the hydroxide ion concentration ([OH⁻]):
[OH⁻] = moles of KOH / volume of solution
= (0.62 g / 56.11 g/mol) / 500 mL
To convert the volume from milliliters (mL) to liters (L), we divide the volume by 1000:
[OH⁻] = (0.62 g / 56.11 g/mol) / (500 mL / 1000 mL/L)
Simplifying the equation gives us the hydroxide ion concentration [OH⁻] in moles per liter (M):
[OH⁻] = (0.62 g / 56.11 g/mol) / (0.5 L)
Finally, we can use the hydroxide ion concentration [OH⁻] to find the pOH. The pOH is the negative logarithm of the hydroxide ion concentration:
pOH = -log([OH⁻])
Once we have the pOH, we can calculate the pH using the formula:
pH = 14 - pOH
By following these calculations, we can obtain the pH of the potassium hydroxide solution.