Discuss the below in detail:
Q: The XYZ Corporation was duly organized on July 10. Its certificate of incorporation provides for total authorized capital of $1 million, consisting of ten thousand shares of common stock with a par value of $100 per share. The corporation issues for cash a total of 500 certificates, numbered 1 to 500 inclusive, representing various amounts of shares in the names of various individuals. The shares were all paid for in advance, so the certificates are all dated and mailed on the same day. The 500 certificates of stock represent a total of 10,500 shares. Certificate 499 for 300 shares was issued to Jane Smith. Certificate 500 for 250 shares was issued to William Jones. Is the validity of the stock thus issued in any way questionable? What are the rights of Smith and Jones?