That all depends on the size of the file(s). It's a hard question to answer. Similar to: How many people can a vehicle hold. How big are the people? If they are kids, you can definitely fit more.
Depends on how your shooting and at what resolution. If your shooting jpeg+raw at 24+ mgp then maybe 500-600 if your just shooting compressed low resolution jpeg then thousands. If you are going to be doing any rapid fire shooting then I would recommend a more expensive card with better bus speeds.
I believe that these memory cards are pretty much standard and should fit just about any camera. I would look at the camera itself just to see what type they use. I'd be willing to say they are very compatible.
I know Kodak cameras use SD cards...however not knowing how new the Kodak C142 camera is...you would have to call/Google Kodak to make sure the C142 can take a 16 gb SD card.
If your camera takes a standard SD card it should work, unless the manufacturer states that it as a storage limit. Some older cameras have them where you can only have up to a certain size of card in it to work.