(A)   The Mayor shall be the contracting officer of the Municipality and shall award and execute all contracts on behalf of the Municipality.
   (B)   When any expenditure or contract is more than the amount specified by the laws of Ohio for which work may be accomplished only after advertisement and bidding, such contract or expenditure shall first be authorized or directed by an ordinance or resolution passed by the Council and shall be advertised once a week for at least two weeks in a newspaper of general circulation in the Municipality; provided the Council, by an ordinance or resolution adopted by a vote of at least three-fourths of its members, may authorize, without advertising and competitive bidding, contracts and expenditures for any purpose where the statutory or common law of Ohio does not require competitive bidding.
   (C)   When it becomes necessary to make alterations or modifications in connection with any work or improvements covered by contract, they shall be made only upon the order of the Mayor. No such order shall be effective until the price to be paid for the work or material, or both, under the altered or modified contract, shall have been agreed upon in writing and signed by the contractor and the Mayor on behalf of the Municipality. Modifications or alterations in contracts shall not require advertising and competitive bidding.
   (D)   No contract, agreement or other contractual obligation involving the expenditure of money shall be entered into or authorized by the Mayor unless the Director of Finance or his or her duly authorized representative shall first certify:
      (1)   That the money required for such contract, agreement, obligation or expenditure is in the Municipality's treasury or in the process of collection thereto, and
      (2)   That the money has been appropriated by Council for the specified purpose, and it remains unencumbered.
   Said certification as to the availability of funds and the appropriation of funds shall be filed and recorded in the accounting records of the Municipality and a copy furnished the vendor or contractor. Without the certification, contractual obligations shall be void and unenforceable against the Municipality unless recognized and authorized to be paid by Council as a moral obligation.
   (E)   The Mayor shall not divide any order or contract to avoid the requirements of competitive bidding.