Answer:
d.) 1.0 M HNO2, 1.0 M NaNO2
Step-by-step explanation:
A buffer is a mixture that is capable of tolerating addition of a strong acid or base without altering the pH substantially.
A buffer is the mixture of a WEAK ACID AND ITS CONJUGATE BASE or a WEAK BASE AND ITS CONJUGATE ACID
In the problems:
a) HCl is a strong acid and NaCl a salt. NO buffer
b) NH3 is a weak base and NaCL a salt. NO buffer
c) HF is a weak acid and NaCl a salt. NO buffer.
d) HNO2 is a weak acid and NaNO2 its conjugate base. A BUFFER