What is the pH of a solution prpared by mixing 50.0 ml of .200 M HCLO4 with 10.0 ml of .100 M KOH
To find the pH of the solution prepared by mixing hydrochloric acid (HClO4) with potassium hydroxide (KOH), you need to first determine the number of moles of each compound present in the solution. Then you can use the principles of acid-base neutralization to determine the resulting pH.
Here's how to calculate the pH step by step:
Step 1: Calculate the number of moles of HClO4.
To find the number of moles, use the formula:
moles = concentration (M) x volume (L)
moles HClO4 = 0.200 M x (50.0 ml / 1000 ml/L)
moles HClO4 = 0.010 mol
Step 2: Calculate the number of moles of KOH.
Using the same formula as above:
moles KOH = 0.100 M x (10.0 ml / 1000 ml/L)
moles KOH = 0.001 mol
Step 3: Determine the limiting reagent.
To determine the limiting reagent, compare the number of moles of both compounds. The compound with the smaller number of moles is the limiting reagent. In this case, KOH is the limiting reagent because it has fewer moles.
Step 4: Determine the excess reagent.
The excess reagent is the compound leftover after the reaction. In this case, HClO4 is the excess reagent because it had more moles initially.
Step 5: Calculate the moles of excess reagent remaining.
To determine how many moles of the excess reagent remain after the reaction, you need to subtract the moles of the limiting reagent used from the initial moles of excess reagent.
moles HClO4 left = moles HClO4 initial - moles KOH used
moles HClO4 left = 0.010 mol - 0.001 mol
moles HClO4 left = 0.009 mol
Step 6: Calculate the concentration of the excess reagent remaining.
To find the concentration of HClO4 after the reaction, divide the moles of HClO4 remaining by the new total volume of the solution (50.0 ml + 10.0 ml).
concentration HClO4 = moles HClO4 left / total volume in liters
concentration HClO4 = 0.009 mol / [(50.0 ml + 10.0 ml) / 1000 ml/L]
concentration HClO4 = 0.150 M
Step 7: Determine the pH.
Since HClO4 is a strong acid and KOH is a strong base, a neutralization reaction occurs between them, resulting in the formation of water. Therefore, the resulting solution will be neutral, and the pH will be 7.
So, the pH of the solution prepared by mixing 50.0 ml of 0.200 M HClO4 with 10.0 ml of 0.100 M KOH is 7.