Answer :
Final Answer:
The concentration of the original Ba(OH)₂ solution.
B: 0.625 M
Explanation:
To find the concentration of the original Ba(OH)₂ solution, we can use the concept of stoichiometry and the equation for neutralization reactions. The balanced equation for the reaction between Ba(OH)₂ and HBr is:
Ba(OH)₂ + 2HBr → BaBr₂ + 2H₂O
From the balanced equation, we see that one mole of Ba(OH)₂ reacts with two moles of HBr. Using the given volumes and concentration of HBr, we can determine the moles of HBr used in the reaction. Then, we use stoichiometry to find the moles of Ba(OH)₂ initially present in the solution. Finally, we divide the moles of Ba(OH)₂ by the volume of the original solution to find its concentration.
The volume of Ba(OH)₂ solution is given as 25.0 mL. The moles of HBr used can be calculated from its concentration and volume used. With the stoichiometry, we find that 0.0158 moles of Ba(OH)₂ are present in the original solution. Dividing this by the volume of the original solution (25.0 mL converted to liters), we find the concentration to be 0.625 M. Therefore, the correct answer is option B: 0.625 M.
