A 0.115-L sample of an unknown HNO3 solution required 31.1 mL of 0.100 M Ba(OH)2 for complete neutralization. What was the concentration of the HNO3 solution?
2HNO3 + Ba(OH)2 ==> Ba(NO3)2 + 2H2O
mols Ba(OH)2 = M x L = ?
convert mols Ba(OH)2 to mols HNO3 using the coefficients in the balanced equation. That is mols HNO3 = 2*mols Ba(OH)2
Then M HNO3 = mols HNO3/L HNO3.
Thank you very much Dr. Bob for your help. I didn't post the original question, but was working on a similar problem. It probably would have taken me an hour to figure this out without your help. Thanks again!
To find the concentration of the HNO3 solution, we can use the concept of stoichiometry and the equation for the neutralization reaction between HNO3 and Ba(OH)2.
The balanced chemical equation for the reaction is:
2 HNO3 + Ba(OH)2 → 2 H2O + Ba(NO3)2
From the equation, we can see that it takes 2 moles of HNO3 to react with 1 mole of Ba(OH)2.
Given:
Volume of HNO3 solution = 0.115 L
Volume of Ba(OH)2 solution = 31.1 mL = 0.0311 L
Concentration of Ba(OH)2 = 0.100 M
First, let's convert the volume of Ba(OH)2 solution to moles using its concentration:
0.100 mol/L * 0.0311 L = 0.00311 mol
Since the reaction stoichiometry states that 2 moles of HNO3 react with 1 mole of Ba(OH)2, we can calculate the moles of HNO3:
0.00311 mol Ba(OH)2 * (2 mol HNO3 / 1 mol Ba(OH)2) = 0.00622 mol HNO3
Finally, we can find the concentration of the HNO3 solution by dividing the moles of HNO3 by the volume of the solution:
0.00622 mol / 0.115 L = 0.0541 M
Therefore, the concentration of the HNO3 solution is approximately 0.0541 M.
To find the concentration of the HNO3 solution, we can use the concept of stoichiometry.
Step 1: Write the balanced chemical equation for the reaction between HNO3 and Ba(OH)2.
HNO3 + Ba(OH)2 -> Ba(NO3)2 + H2O
Step 2: Determine the molar ratio between HNO3 and Ba(OH)2 from the balanced equation. From the equation, we can see that 1 mol of HNO3 reacts with 2 mol of Ba(OH)2.
Step 3: Calculate the number of moles of Ba(OH)2 used in the reaction.
Using the equation: moles = (volume in liters) x (concentration in mol/L)
moles of Ba(OH)2 = 0.0311 L x 0.100 mol/L = 0.00311 mol
Step 4: Use the molar ratio to find the number of moles of HNO3.
Since 1 mol of HNO3 reacts with 2 mol of Ba(OH)2, we can set up a ratio:
moles of HNO3 / moles of Ba(OH)2 = 1 / 2
moles of HNO3 = (0.00311 mol) x (1 mol HNO3/2 mol Ba(OH)2) = 0.00155 mol
Step 5: Calculate the concentration of the HNO3 solution.
The concentration of HNO3 (in mol/L) is given as moles divided by the volume in liters.
Concentration of HNO3 = (0.00155 mol) / (0.115 L) ≈ 0.0135 M
Therefore, the concentration of the HNO3 solution is approximately 0.0135 M.