Before installing SSL certificate and Intermediate CA certificate on Web server such as Apache, you may want to verify them.
You can do it using OpenSSL openssl command.

Start SSL/TLS server using openssl s_server

s_server implements a generic SSL/TLS server which accepts connections from remote clients speaking SSL/TLS.

openssl s_server -cert <path/to/certificate> -key <path/to/private key> -CAfile <path/to/Intermediate CA certificate>

Example:

$ openssl s_server -cert server.crt -key server.key -CAfile intermediate.crt 
Using default temp DH parameters
Using default temp ECDH parameters
ACCEPT

Test with openssl s_client

Connect to the server using openssl s_client and verify certificates.
s_client implements a generic SSL/TLS client which can establish a transparent connection to a remote server speaking SSL/TLS.

openssl s_client -connect localhost:4433 -CAfile <path/to/CA certificate>

Example of CA certificate:

• Mac OS X
  /etc/openssl/cert.pem
  /opt/local/etc/openssl/cert.pem、/opt/local/share/curl/curl-ca-bundle.crt (with MacPorts)
• Ubuntu (You need to install ca-certificates using apt)
  /etc/ssl/certs/ca-certificates.crt
• CentOS
  CA certificate id in /etc/pki/tls/certs/ca-bundle.crt but you don't have to specify it.

Example:

$ openssl s_client -connect localhost:4433 -CAfile /opt/local/share/curl/curl-ca-bundle.crt
CONNECTED(00000003)
depth=3 (omitted)
verify return:1
depth=2 (omitted)
verify return:1
depth=1 (omitted)
verify return:1
depth=0 (omitted)
verify return:1
---
Certificate chain
 0 s:(omitted)
   i:(omitted)
 1 s:(omitted)
   i:(omitted)
 2 s:(omitted)
   i:(omitted)
 3 s:(omitted)
   i:(omitted)
---
Server certificate
-----BEGIN CERTIFICATE-----
(omitted)
-----END CERTIFICATE-----
subject=(omitted)
issuer=(omitted)
---
No client certificate CA names sent
---
SSL handshake has read 4744 bytes and written 443 bytes
---
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES256-GCM-SHA384
Server public key is 2048 bit
Secure Renegotiation IS supported
Compression: zlib compression
Expansion: zlib compression
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : ECDHE-RSA-AES256-GCM-SHA384
    Session-ID: (omitted)
    Session-ID-ctx: 
    Master-Key: (omitted)
    Key-Arg   : None
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    TLS session ticket lifetime hint: 300 (seconds)
    TLS session ticket:
    (omitted)
    Compression: 1 (zlib compression)
    Start Time: 1421023132
    Timeout   : 300 (sec)
    Verify return code: 0 (ok)
---

After you have installed certificates on the server, verify them with s_client like below.
-servername is needed for SNI (Server Name Indication).

• Mac OS X

  $ openssl s_client -connect www.example.com:443 -servername www.example.com -showcerts -CAfile /opt/local/etc/openssl/cert.pem
  

• CentOS

  $ openssl s_client -connect www.example.com:443 -servername www.example.com -showcerts
  

• Ubuntu
  (You need to install ca-certificates using apt)

  $ openssl s_client -connect www.example.com:443 -servername www.example.com -showcerts -CAfile /etc/ssl/certs/ca-certificates.crt
  

If you want to show expiring date of certificate,

$ echo | openssl s_client -connect www.example.com:443 -servername www.example.com -showcerts 2>/dev/null | openssl x509 -noout -dates