A perchloric acid solution is titrated using barium hydroxide. if the complete neutralization of 50 ml of the HClO4 solution requires 37 ml of 0.125 M Ba(OH)2, what is the molarity of the HClO4?
The Correct Answer and Explanation is:
To solve this titration problem, we need to follow these steps:
Step 1: Write the balanced chemical equation for the neutralization reaction.
The reaction between perchloric acid (HClO4) and barium hydroxide (Ba(OH)2) is:
2 HClO4(aq)+Ba(OH)2(aq)→Ba(ClO4)2(aq)+2H2O(l)\text{2 HClO4} (aq) + \text{Ba(OH)2} (aq) \rightarrow \text{Ba(ClO4)2} (aq) + 2 \text{H2O} (l)2 HClO4(aq)+Ba(OH)2(aq)→Ba(ClO4)2(aq)+2H2O(l)
This equation tells us that 2 moles of HClO4 react with 1 mole of Ba(OH)2.
Step 2: Use the titration data to calculate moles of Ba(OH)2.
We are given that the volume of Ba(OH)2 solution is 37 mL (which is 0.037 L) and the molarity of Ba(OH)2 is 0.125 M.
To calculate the moles of Ba(OH)2 used in the reaction:moles of Ba(OH)2=M×V\text{moles of Ba(OH)2} = M \times Vmoles of Ba(OH)2=M×Vmoles of Ba(OH)2=0.125 mol/L×0.037 L=0.004625 mol\text{moles of Ba(OH)2} = 0.125 \, \text{mol/L} \times 0.037 \, \text{L} = 0.004625 \, \text{mol}moles of Ba(OH)2=0.125mol/L×0.037L=0.004625mol
Step 3: Calculate the moles of HClO4.
From the balanced chemical equation, we know that 2 moles of HClO4 react with 1 mole of Ba(OH)2. So, the moles of HClO4 will be double the moles of Ba(OH)2.moles of HClO4=2×0.004625 mol=0.00925 mol\text{moles of HClO4} = 2 \times 0.004625 \, \text{mol} = 0.00925 \, \text{mol}moles of HClO4=2×0.004625mol=0.00925mol
Step 4: Calculate the molarity of HClO4.
The molarity of the HClO4 solution is defined as:Molarity of HClO4=moles of HClO4volume of HClO4 solution in L\text{Molarity of HClO4} = \frac{\text{moles of HClO4}}{\text{volume of HClO4 solution in L}}Molarity of HClO4=volume of HClO4 solution in Lmoles of HClO4
We are given that the volume of HClO4 is 50 mL, which is 0.050 L.Molarity of HClO4=0.00925 mol0.050 L=0.185 M\text{Molarity of HClO4} = \frac{0.00925 \, \text{mol}}{0.050 \, \text{L}} = 0.185 \, \text{M}Molarity of HClO4=0.050L0.00925mol=0.185M
Final Answer:
The molarity of the HClO4 solution is 0.185 M.
Explanation:
By applying the principles of stoichiometry, we used the molarity and volume of the Ba(OH)2 solution to find the moles of Ba(OH)2 that were used. From the balanced equation, we then determined the moles of HClO4 that reacted. Finally, we divided the moles of HClO4 by the volume of the HClO4 solution to find its molarity.
