A 500.0-mL buffer solution is 0.100 M in HNO₂ and 0.150 M in KNO₂. Determine if each addition would exceed the capacity of the buffer to neutralize it. d. 1.35 g HI

Verified step by step guidance

1. Calculate the moles of HNO_2 and KNO_2 in the buffer solution using the formula: moles = concentration (M) \times volume (L).
2. Determine the moles of HI added by converting the mass of HI to moles using its molar mass.
3. Identify the buffer components: HNO_2 is the weak acid and NO_2^- (from KNO_2) is the conjugate base.
4. Assess the buffer capacity by comparing the moles of HI added to the moles of the buffer components. A buffer can typically neutralize an amount of strong acid or base that is less than or equal to the moles of the weak acid or conjugate base present.
5. Conclude whether the addition of HI exceeds the buffer capacity by checking if the moles of HI are greater than the moles of NO_2^- available to neutralize it.

Key Concepts

Buffer Solutions

Buffer solutions are mixtures that resist changes in pH when small amounts of acid or base are added. They typically consist of a weak acid and its conjugate base or a weak base and its conjugate acid. In this case, the buffer is composed of HNO2 (a weak acid) and KNO2 (its conjugate base), which helps maintain the pH of the solution despite the addition of HI.

Buffer Capacity

Buffer capacity refers to the amount of acid or base that a buffer can neutralize before a significant change in pH occurs. It is influenced by the concentrations of the weak acid and its conjugate base in the solution. To determine if the addition of HI exceeds the buffer's capacity, one must calculate how much H+ ions are introduced and compare it to the buffer's ability to neutralize them.

Stoichiometry of Acid-Base Reactions

Stoichiometry involves the calculation of reactants and products in chemical reactions. In the context of the buffer solution, it is essential to understand the molar relationships between HI and the components of the buffer. By converting the mass of HI to moles and comparing it to the moles of HNO2 available, one can assess whether the buffer can effectively neutralize the added acid without exceeding its capacity.