Hello,
Say 1st IP is 172.78.85.9 and 2nd IP is 172.78.85.10 , the virtualhost will be like this,
Listen 80
# This is the "main" server running on 172.20.30.40
ServerName server.domain.com
DocumentRoot /www/mainserver
# This is the other address
NameVirtualHost 172.78.85.9:80
<VirtualHost 172.78.85.9:80>
DocumentRoot /var/www/site1
ServerName
www.example1.com
# Other directives here ...
</VirtualHost>
NameVirtualHost 172.78.85.10:80
<VirtualHost 172.78.85.10:80>
DocumentRoot /var/www/site2
ServerName
www.example2.org
# Other directives here ...
</VirtualHost>