# Buffer with Acid and Base Chem Question? Help Please?

A buffer contains significant amounts of ammonia and ammonium chloride.

a. Write an equation showing how this buffer neutralizes added acid (HI).

Here's what I have; where am I going wrong??

NH3+HI---->NH4+ + I-.

b.Write an equation showing how this buffer neutralizes added base (Ba(OH)2)

Again, apparently, I am going wrong; how?

Thanks.

BaOH2+2HCl----->BaCl2+2H2O

Thank you for any help!!!

Chemteam: Thanks but apparently they wanted HI NH3---- NH4I. I am STILL not sure why.

• Since HI is a strong acid, you could do this:

NH3+H+ ---->NH4+

Neutralizing the base is this reaction:

NH4+ + OH- ---> NH3 + H2O

The reaction you wrote:

Ba(OH)2+2HCl----->BaCl2+2H2O

is that of a strong base (the Ba(OH)2) reacting with a strong acid (the HCl).

Source(s): ChemTeam
• The solution contains NH4+ (ammonium chloride) and NH3 (ammonia). Adding the strong acid HI is adding H+ ions. The H+ ions will react with NH3 to produce more NH4+:

HI + NH3 ----> NH4+ + I-

this reduces the concentration of NH3 and increases the concentration of NH4+ The equation for a basic buffer is pOH = pKb + log[NH4+]/[NH3]. the log term increases, so the pOH increases and the pH decreases.

OH- from Ba(OH)2 reacts with the NH4+ ions in the buffer.

OH- + NH4+ ----> NH3 + H2O

[NH3] increases and [NH4+] decreases, the reverse of above