The invention describes a tank comprising a solution, dispersion or emulsion for selective catalytic reduction in combustion engines. The tank comprises an electrical resistive heating element immersed in the tank. The electrical resistive heating element comprises at least one heating cord. The heating cord comprises metal filaments. The metal filaments •comprise a copper layer or a layer in a copper alloy, and comprise a surrounding layer in stainless steel, •or comprise a steel layer, surrounded by a layer in copper or in a copper alloy, surrounded by a nickel, zinc or tin layer or a layer of alloys comprising such metals; •or comprise a layer of low carbon or high carbon steel, and comprise a surrounding nickel, zinc or tin layer or layer of alloys comprising such metals, and the heating cord comprises a polymer coating layer.