An aqueous solution of hydrobromic acid can be formed by dissolving 12.5 L of HBr gas at 25.0 °C and 1 atm in 500 mL of water. Calculate the number of moles (in 3 s.f.) of HBr in the solution if all the gas solute dissolves in the water.

• A. 0.125 mol
• B. 0.511 mol
• C. 1.00 mol
• D. 1.02 mol

Answer: (B)