How the selection of IP address is done for a tcp socket on client side if there are multiple alias configured

Hi all,

What i want to know is :
As , generally we don't specify IP address from client while making
connect call, system does select one while sending syn request with
some IP address. How does system makes this choice ?? If there are
multiple NIC cards present ,then which IP is used ?? If there is single
NIC card , but many alias created , then which IP address from these is
selected for outgoing request ??

Can somebody point me to exact location in linux networking code ,
where this can cross checked ??

Also is it possible , to hide any ip address from this alias list ,
so that no outgoing connection will use it ??

Thanks in advance ,
Rohit