When hydrobromic acid (HBr) is titrated with 0.160 M NaOH, the endpoint is reached after the addition of 39.56 mL of NaOH. If 18.48 mL of HBr were used, what is the concentration of the HBr?
3.43 x 10–1 M
1.31 x 10–1 M
7.62 x 10–1 M
7.47 x 10–2 M
- electron1Lv 72 years ago
Since hydrobromic acid has one H and sodium hydroxide has one OH, one mole of the acid will neutralize the base. To determine the number of moles, multiply the volume in liters by the molarity.
For NaOH, n = 0.03956 * 0.160 = 0.0063296
For HBr, n = 0.01848 * M
0.01848 * M = 0.0063296
M = 0.0063296 ÷ 0.01848
This is approximately 0.3425 moles per liter. The first answer is the correct answer.