The formula for the conjugate base of formic acid (HCHO2) is the formate ion (CHO2-).
The acid in question is formic acid (HCHO2). To determine the formula for its conjugate base, we need to identify the ion formed when the acidic proton (H+) is removed. In this case, removing the proton from formic acid results in the formate ion (CHO2-) as its conjugate base.
Formate ion (CHO2-) has a negative charge, indicating that it has accepted the proton from the acid. The removal of the proton leaves behind an anion with a full negative charge. The conjugate base, in this context, has one fewer hydrogen ion compared to the acid, and it carries a negative charge.
Therefore, the formula for the conjugate base of formic acid (HCHO2) is the formate ion (CHO2-).