What does this rebus picture identify?

My first is in chocolate but not in ham. My second is in cake and also in jam. My third at tea time is easily found. Altogether, this is a friend who is often around. What is it?

John was piloting a plane behind a car but was never able to overtake it. Why?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?

How many sides does a circle have?

I am white when I am dirty, and black when I am clean. What am I?

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?