Question

Which of the following mixtures would result in buffered solutions when 1.0 L of each of the two solutions are mixed?

a) 0.10 M NaCl and 0.10 M NaNO2
b) 0.10 M NaCl and 0.10 M NH4Cl
c) 0.10 M CH3NH2 and 0.15 M CH3NH3Cl
d) 0.10 M HCl and 0.05 M NaNO2
e) 0.10 M HCL and 0.20 M NaC2H302
f) 0.1 M CH3COO and 0.15 M NaC2H5OO

Please explain i have a final tomorrow.

I know the a buffer is a mixture of a weak acid or base ans its conjugate base.

So d and e have HCl which is a strong acid so they are not one of the right answers i think.

Answer 1

c is a buffered solution. CH3CH2NH2 is a weak base (ethyl amine) and the salt. I don't think any of the other will qualify.
a is a salt and a salt.
b is a salt and a salt.
c is buffered.
d and e, as you correctly point out, contain a strong acid so they are out.