The answer to your question depends on how fast you drive and how many stops you have.
About 20 hours.
Iowa is 310 miles long from north to south.
Assuming you're going across Interstate 80, that roads spans 306 miles through Iowa, and typically has a 75 MPH speed limit. If you were to actually average 75 MPH and not stop for fuel, bathroom breaks, etc, you'd be looking at a little over four hours of driving.
how long will it take to drive from scott city, iowa to decatur, illinois
The drive time from Iowa (IA) to Washington, District of Columbia is:15 hours, 39 minutes
18 hours
100 miles
two hours
Driving across Illinois on Interstate 80 typically takes about 4 to 5 hours, depending on traffic conditions and stops along the way. The distance is approximately 160 miles from the eastern to the western border of the state. Factors such as weather, construction, and time of day can affect travel time.
If you're talking Iowa the state then it's about 18 to 20 hours...
About 4.5 hours.
About 10 hours.