Which of the following mixtures will result in the formation of a buffer solution when dissolved in 1.00 L of water?
i) 0.50 mol NaOH and 0.50 mol HCl.
ii) 0.50 mol NaCl and 0.25 mol HCl.
iii) 0.50 mol NaF and 0.25 mol HF.
iv) 0.50 mol NaOH and 0.25 mol HF.
v) 0.25 mol NaOH and 0.50 mol HF.
iii and v
You are correct.
To determine which mixture will result in the formation of a buffer solution, we need to understand what constitutes a buffer solution.
A buffer solution is a solution that resists changes in pH when a small amount of acid or base is added to it. It consists of a weak acid and its conjugate base, or a weak base and its conjugate acid.
In this case, we have several mixtures of compounds, and we need to identify if any of them contain a weak acid and its conjugate base or a weak base and its conjugate acid.
Let's analyze each option:
i) 0.50 mol NaOH and 0.50 mol HCl.
NaOH is a strong base, and HCl is a strong acid. Both compounds dissociate completely in water, so they do not form a weak acid-base pair. Therefore, this mixture will not result in the formation of a buffer solution.
ii) 0.50 mol NaCl and 0.25 mol HCl.
NaCl is a salt formed by the reaction between a strong acid (HCl) and a strong base (NaOH). It does not possess any acidic or basic properties. Therefore, this mixture will not result in the formation of a buffer solution.
iii) 0.50 mol NaF and 0.25 mol HF.
NaF is a salt formed by the reaction between a strong acid (HF) and a strong base (NaOH). Similar to the previous option, it does not possess any acidic or basic properties. Therefore, this mixture will not result in the formation of a buffer solution.
iv) 0.50 mol NaOH and 0.25 mol HF.
NaOH is a strong base, while HF is a weak acid. This combination can potentially form a buffer solution if the weak acid (HF) is present in sufficient quantity. However, the ratio of NaOH to HF is 2:1, which means the weak acid is not present in sufficient quantity to form a buffer solution. Therefore, this mixture will not result in the formation of a buffer solution.
v) 0.25 mol NaOH and 0.50 mol HF.
Similar to the previous option, this combination consists of a strong base (NaOH) and a weak acid (HF). However, in this case, the ratio of NaOH to HF is 1:2, which means the weak acid is present in sufficient quantity to form a buffer solution. Therefore, this mixture will result in the formation of a buffer solution.
In conclusion, option (v) 0.25 mol NaOH and 0.50 mol HF is the mixture that will result in the formation of a buffer solution.