will 1 molar NH3 and 1 molar NH4Cl form a buffered solution?
yes and the pH of such a solution will ber the pKa of the base.
To determine if a solution is buffered, you need to compare the concentrations of the conjugate acid-base pair present in the solution. In this case, the conjugate acid-base pair is NH3/NH4+.
To form a buffered solution, the concentration of the weak acid and its conjugate base should be roughly equal or have a ratio of 1:1. In other words, the concentration of NH3 and NH4+ ions should be approximately the same.
In your case, if you have a 1 molar solution of NH3 and a 1 molar solution of NH4Cl, the concentration of NH3 will be 1 M and the concentration of NH4+ ions will also be 1 M.
Since the concentrations are equal, the solution should be buffered. Keep in mind that other factors like pH may be significant in determining whether a solution is effectively buffered, but based on the concentrations alone, this should be a buffered solution.