Who liable for tax.

Any person, firm or corporation who grants, assigns, transfers, or conveys any land, tenement, or realty by a deed, writing, or instrument subject to the tax imposed by this chapter shall be liable for such tax but no public official shall be liable for a tax with respect to any instrument executed by the public official in connection with official duties. [C66, 71, 73, 75, 77, 79, 81, §428A.3 ]