Which solution is a buffer? which solution is a buffer? a solution that is 0.100 m in hno3 and 0.100 m in nano3 a solution that is 0.100 m in hno2 and 0.100 m in nano2 a solution that is 0.100 m in hno2 and 0.100 m in hcl a solution that is 0.100 m in hno2 and 0.100 m in nacl?

Hello!

The solution that is a buffer is a solution that is 0.100 M in HNO₂ and 0.100 M in NaNO₂  

The condition for a buffer solution is that it needs to be formed of a weak acid and its conjugate base, or a weak base and its conjugate acid. From the list, the only set of compounds that is an Acid and its conjugate base is HNO₂ (Weak Acid) and NaNO₂ (Conjugate Base). The pH of this solution would be the same as the pKa of HNO₂ (3,15) since both concentrations are equal.

Have a nice day! 

Well to my expert knowledge and my exquisite calculations i think the the negative ion # 412 is the key to sucess