What destination IP address will PC1 place in the header for a packet destined for PC2?

A data packet is split into three parts: The header, the payload and the trailer.

The header contains the basic instructions about the data packet which should include:

The packet length

Synchronization (a few check bits to match up to the network)

Originating IP Address (i.e. PC 1)

Destination IP Address (i.e. PC 2)

Protocol

Packet number

The payload is the main body of data that is being sent. The size of the data can be a fixed length or a variable amount. If it is a fixed length, then this can be padded with blank data, so that each packet remains the same size.

The trailer or footer contains data that tells the destination computer that it has reached the end of the packet. The trailer may also contain error checking information. This will tell the receiving computer to tell the originating source that the information was received.