Determining [H3O+), (OH), POH and pH in a Neutralization Reaction

Understanding the Neutralization Reaction

When 45mL of 0.20M HBr is mixed with 115mL of 0.25M KOH, a neutralization reaction occurs. In this reaction, the H+ ions from the acid (HBr) combine with the OH- ions from the base (KOH) to form water. The remaining ions after neutralization are used to determine the concentration of [H3O+), (OH), POH and pH.

Final Answer

The concentration of [H3O+), (OH), POH and pH can be determined by analyzing the neutralization reaction between HBr and KOH. With equal moles of H+ and OH- ions produced, the concentration of [H3O+] will be equal to that of KOH. Similarly, the concentration of (OH) will be equal to that of HBr. Lastly, the pH can be calculated using the equation pH + pOH = 14.

Explanation

To determine the [H3O+], we can use the concept of neutralization reaction between the acid (HBr) and the base (KOH). Since the mole ratio of HBr to KOH is 1:1, we have equal amounts of H+ and OH- ions produced. Therefore, the concentration of H3O+ will be equal to the concentration of KOH, which is 0.25 M.

To find the concentration of OH-, we can use the same reasoning. The concentration of OH- is equal to the concentration of HBr, which is 0.20 M.

Using the equation pH + pOH = 14, we can calculate the pH and pOH. The pOH is equal to -log[OH-], so pOH = -log(0.20) = 0.70. Therefore, the pH is 14 - 0.70 = 13.30.