How long the ISS is visible in the night sky, and also how bright it will appear on any given visible pass, depends on how high it is in the sky (ie, angle above the horizon) and how soon after sunset the pass is. When a pass is very high in the sky, say, 60-85 degrees above the horizon, it can be visible for 4 or 5 minutes. And if a particular pass is sufficiently long after sunset, the ISS will fade and ultimately "disappear" mid-pass. This is because the Sun is below the western horizon enough such that the Earth 'gets in the way' and casts a shadow on objects at that general range above Earth. ISS is brightest during high angle passes. And it appears to be moving across the sky at the apparent rate of a high flying airplane. It's actually traveling about 18,000 miles/hr, or 5 miles/sec. 200 or so miles up.
if you have a motorized telescope can it be programmed to track it?
how about a good set of binoculars?
it would be cool to spot it if you can make out the shape