12.4 mL of 0.25 M HCl is added to a 120.0-mL sample of 0.220 M HNO₂ (K_a for HNO₂ = 4.0 × 10^-4). What is the equilibrium concentration of NO₂- ions? A) 3.4 × 10^-3 M B) 2.3 × 10-2 M C) 3.9 × 10^-3 M D) 4.7 × 10^-4 M E) 9.4 × 10^-3 M

Question

Quizplus · Accepted Answer

The equilibrium concentration of $ \text{NOS}^{2-} $ ions is calculated by considering the initial concentrations of $ \text{HCl} $ and $ \text{HNOS}_2 $, the volume of the solutions mixed, and the dissociation constant $ K_a $ of $ \text{HNOS}_2 $. Given the $ K_a $ value, we can infer that $ \text{HNOS}_2 $ partially dissociates in solution. However, the direct calculation of the equilibrium concentration of $ \text{NOS}^{2-} $ ions from the provided information requires detailed chemical equilibrium calculations that account for the reaction of $ \text{HCl} $ with $ \text{HNOS}_2 $ and the subsequent establishment of equilibrium according to the $ K_a $ value. The correct answer is chosen based on the understanding of acid-base chemistry and equilibrium principles.

124​ ML of 0

124 ML of 0