BQ24735EVM-710: Why 1uF capacitor is used at ACP pin?

Hi,

C25 connects from ACP to GND and helps with common-mode filtering. In fact, all 4 capacitors in the screenshot you sent are used for filtering, as described below:

However, C25 is not necessary, and you can safely leave it out of your circuit. The typical application diagram in the datasheet also omits this capacitor.

Best regards,

Angelo