Usually, when you compile your apache2 server (or install it by packages facility stuff), you can check any directive that're available to be used by tapping this command:
~# $(which httpd) -L | grep SSL # on RHEL/CentOS/Fedora
~# $(which apache2) -L | grep SSL # on Ubuntu/Debian
If you don't see any SSL* directive, it means that you don't have apache2 with mod_ssl compiled.
Hopes it helps ;)