The power steering fluid reservoir on a 2005 Chevy Impala is typically located
under the hood, near the front of the engine. It's usually a small, clear or translucent plastic reservoir with markings indicating the minimum and maximum fill lines. Look for a reservoir with a cap that says "Power Steering Fluid" or has a steering wheel symbol on it. It's often near the master cylinder (brake fluid reservoir) but not always directly adjacent.
Because the exact location can vary slightly depending on engine type and specific trim level, it's best to consult your owner's manual for the precise location and to see a diagram if one is included. A quick online search for "2005 Chevy Impala power steering fluid reservoir location" with images will also likely show you a picture of where it's located on a similar vehicle.