Which of the following solutions result in a buffer ?

[SamTsui86]

Homework Statement

2. [1pt]

Which of the following solutions result in a buffer ?



a) 0.100 L of 0.250 M NH3 + 0.050 L of 0.250 M HCl


b) 0.100 L of 0.250 M NH3 + 0.100 L of 0.250 M HCl


c) 0.100 L of 0.250 M NH4Cl + 0.050 L of 0.250 M NaOH


d) 0.100 L of 0.250 M NH4Cl + 0.150 L of 0.250 M NaOH

Homework Equations

M = mol/V

The Attempt at a Solution

so I got the mol for each one, they are

1) .025 mol and .0125 mol
2) .025 mol and .025 mol
3) .025 mol and .0125 mol
4) .025 mol and .0375 mol

I don't know how to do it, please help help

 

[symbolipoint]

Simply check which situation conforms to the definition of a pH buffer. You first know that ammonium and chloride are "completely" ionized in water solution. Now, in which solution exists either a weak base and salt of that base; or an weak acid and a salt of that acid?