The county board, at its first session in each year, shall elect from its members a chair and a vice-chair. The chair shall preside at its meetings and sign all documents requiring signature on its behalf. The chair's signature, attested by the clerk of the county board, shall be binding as the signature of the board. In case of the absence or incapacity of the chair, the vice-chair shall perform the chair's duties. If the chair or vice-chair are absent from any meeting, all documents requiring the signature of the board shall be signed by a majority of it and attested by the clerk.