You must provide the infrastructure required by httpd within the chroot. I recommend copying /var/www's directory structure into your /chroot/home -- you'll need a logs directory at minimum, and you may need other structures already found in /var/www. Copying all of them is probably easiest.
You can run httpd in a console with -d, for testing, and you can add one (or more ) -v options to produce debug output.
Just in case you are not already aware of it ... there are reliability (#9) and security (#15)
patches for httpd available for 5.6-release.