Sinve CH3NH2 is weak base and its salt is CH3NH3Cl, mixing 125.0 mL of CH3NH2 and 120.0 mL of CH3NH3Cl so produce a buffer.
<h3>What is a buffer?</h3>
A buffer is a solution which resists changes to its pH when a small quantity of strong acid or base is added to it..
A buffer is made from a weak acid and its salt or a weak base and its salt.
From the given options, CH3NH2 is weak base and its salt is CH3NH3Cl.
Therefore, mixing 125.0 mL of CH3NH2 and 120.0 mL of CH3NH3Cl so produce a buffer.
Learn more about buffers at: brainly.com/question/1385846
