To determine whether a 0.1M solution of NaNO2 is acidic or basic, we need to consider the nature of the salt and its dissociation in water.

Sodium nitrite (NaNO2) is a salt composed of sodium ions (Na+) and nitrite ions (NO2-). When dissolved in water, it dissociates into these ions:

NaNO2(s) → Na+(aq) + NO2-(aq)

The sodium ions are positively charged, while the nitrite ions are negatively charged. The dissociation of NaNO2 does not produce any hydrogen ions (H+) or hydroxide ions (OH-) that could significantly affect the pH of the solution.

Therefore, a 0.1M solution of NaNO2 is considered to be neutral. It does not exhibit significant acidic or basic properties due to the dissociation of its constituent ions.