which will become a buffer in 1L of H2O?
a) 0.3 mole KOH & 0.3 mole HBr
b) 0.5 mole NH3 & 0.5 mole HCl
c) 0.2 mole NaCl & 0.3 mole HCl
d) 0.2 mole NaOH & 0.2 mole HBr
e) 0.4 mole HC2H3O2 & 0.2 mole NaOH
I think that the answer is e. Is that correct?
yes.
To determine which solution will become a buffer in 1L of H2O, we need to identify a weak acid and its conjugate base, or a weak base and its conjugate acid. A buffer solution consists of a weak acid and its conjugate base, or a weak base and its conjugate acid. The ratio of these two components should be similar to maintain the pH of the solution.
Let's analyze each option:
a) 0.3 mole KOH & 0.3 mole HBr: This solution contains a strong base (KOH) and strong acid (HBr) and does not form a buffer.
b) 0.5 mole NH3 & 0.5 mole HCl: This solution contains a weak base (NH3) and a strong acid (HCl). It could potentially form a buffer.
c) 0.2 mole NaCl & 0.3 mole HCl: This solution contains a strong base (NaCl) and a strong acid (HCl) and does not form a buffer.
d) 0.2 mole NaOH & 0.2 mole HBr: This solution contains a strong base (NaOH) and a strong acid (HBr) and does not form a buffer.
e) 0.4 mole HC2H3O2 & 0.2 mole NaOH: This solution contains a weak acid (HC2H3O2) and a strong base (NaOH). It could potentially form a buffer.
Based on the analysis, option e) 0.4 mole HC2H3O2 & 0.2 mole NaOH is correct. This solution contains a weak acid (HC2H3O2) and its conjugate base (C2H3O2- from NaOH). The weak acid and its conjugate base allow the solution to resist changes in pH when an acid or a base is added.
Therefore, the correct answer is e) 0.4 mole HC2H3O2 & 0.2 mole NaOH.