A 250.0 ml sample of gaseous hydrogen bromide,measured at 22.9 °C and 0.930 atm,was dissolved in sufficient pure water to form 250.0 ml of solution.What was the pH of that solution?
A)1.42
B)2.58
C)3.83
D)4.18
E)5.68

Question

Quizplus · Accepted Answer

The pH of the solution can be calculated by first determining the concentration of hydrogen bromide (HBr) in the solution. Since HBr is a strong acid, it will dissociate completely in water, and the concentration of HBr will be equal to the concentration of H+ ions, which determines the pH.1. Use the ideal gas law (PV = nRT) to find the number of moles of HBr. P = 0.930 atm, V = 0.250 L, R = 0.0821 L·atm/(mol·K), T = 22.9°C + 273.15 = 296.05 K.$$ n = \frac{PV}{RT} = \frac{0.930 \times 0.250}{0.0821 \times 296.05} \approx 0.0093 \, \text{mol} $$2. The concentration of HBr in the solution is the number of moles divided by the volume of the solution in liters, which is 0.250 L.$$ \text{Concentration of HBr} = \frac{0.0093}{0.250} = 0.0372 \, \text{M} $$3. Since HBr is a strong acid, it dissociates completely, and the concentration of H+ ions is the same as the concentration of HBr. The pH is calculated using the formula:$$ \text{pH} = -\log[\text{H}^+] $$$$ \text{pH} = -\log[0.0372] \approx 1.42 $$Therefore, the pH of the solution is approximately 1.42.

A 2500 Ml Sample of Gaseous Hydrogen Bromide,measured at 22