Question

16

options to choose from are

pKa

OH^-

H2O

NH3

concentration

NH4Cl

H3O^+

Question 16 Tries remaining 1 Points out of 1.00 P Flag question Select the correct answer to the questions below with regards to the NH3/NH4Cl buffer. Multiple tries are permitted; however, 25% (1/4) point will be deducted for each incorrect response. What characteristic of this buffer will improve its buffer capacity? What component of the buffer will NaOH react with when added to the buffer mixture? What component of the buffer will HCl react with when added to the buffer mixture? Choose. Choose. Choose. Check

Answer 1

Question are regarding buffer NH₃/NH₄Cl :

It is buffer of weak base and salt of its conjugated acid (called basic buffer ).

1. Buffer capacity of a solution is defined in terms of buffer index (concentration of buffer acid /base required to change its pH value by one).

pH of this buffer solution is defined by ratio of concentration of salt and base : so concentration will improve its buffer capacity.

2.

When NaOH added to this buffer mixture , ammonium ion (from NH₄Cl component ) reacts with hydroxide ions introduced by NaOH (strong base) :

NH₄⁺ (aq) + OH^-(aq) $\rightleftharpoons$  NH₄OH $\rightarrow$ NH₃(aq) + H₂O(l)

3.

When HCl added to this buffer mixture , NH₃ molecules reacts with protons introduced by HCl (strong acid) :

NH₃ (aq)+ H⁺(aq)  $\rightarrow$   NH₄⁺ (aq)