What volume of a 0.332 M hydrobromic acid solution is required to neutralize 29.6 mL of a 0.155 M calcium hydroxide solution ?
Ca(OH)2 + 2HBr ==> CaBr2 + 2H2O
mols Ca(OH)2 = M x L = ?
mols HBr = twice that (from the coefficients in the equation).
M HBr = mols HBr/L HBr. You know M and mols, solve for L HBr and convert to mL.
To calculate the volume of the hydrobromic acid solution required to neutralize the calcium hydroxide solution, you can use the concept of molar equivalence.
Step 1: Write the balanced chemical equation for the reaction between hydrobromic acid (HBr) and calcium hydroxide (Ca(OH)2):
2 HBr + Ca(OH)2 → CaBr2 + 2 H2O
Step 2: Determine the molar ratio between HBr and Ca(OH)2 from the balanced equation. In this case, the ratio is 2:1. This means that 2 moles of HBr are required to react with 1 mole of Ca(OH)2.
Step 3: Calculate the number of moles of Ca(OH)2 in the given volume (29.6 mL) and concentration (0.155 M) using the formula:
moles = volume (in L) × concentration (in mol/L)
moles of Ca(OH)2 = 29.6 mL × 0.155 mol/L = 4.588 × 10^-3 mol
Step 4: Use the molar ratio from step 2 to determine the number of moles of HBr required to neutralize the given amount of Ca(OH)2. Since the ratio is 2:1, twice the number of moles of Ca(OH)2 are required:
moles of HBr = 2 × moles of Ca(OH)2 = 2 × 4.588 × 10^-3 mol = 9.176 × 10^-3 mol
Step 5: Finally, calculate the volume of the hydrobromic acid solution required to contain the calculated moles of HBr at its given concentration (0.332 M):
volume (in L) = moles / concentration (in mol/L)
volume of HBr solution = 9.176 × 10^-3 mol / 0.332 mol/L = 0.0276 L
To convert the volume to milliliters,
volume (in mL) = volume (in L) × 1000 = 0.0276 L × 1000 = 27.6 mL
Therefore, approximately 27.6 mL of the 0.332 M hydrobromic acid solution is required to neutralize 29.6 mL of the 0.155 M calcium hydroxide solution.