Tin oxides dissolve in acids. Halogen acids attack SnO2 to give hexahalostannates, e.g. [SnI6]2−. One report describes reacting a sample in refluxing HI for many hours.
SnO2 dissolves in strong base to give "stannates," with the nominal formula Na2SnO3. Dissolving the solidified SnO2/NaOH melt in water gives Na2[Sn(OH)6]2, "preparing salt," which is used in the dyeing industry.
Throughout history it has been used as an opacifier in the ceramic industry (where it is just known as tin oxide), especially in earthenware. Tin oxide does not go into solution in the glaze melt, generally amounts of 4-8% are needed. Zircon compounds are also used for this purpose.
SnO2 coatings can be applied using CVD, vapour deposition techniques that employ SnCl4 or organotin trihalides e.g. butyltin trichloride as the volatile agent. This technique is used to coat glass bottles with a thin (<0.1 μm) layer of SnO2, which helps to adhere a subsequent, protective polymer coating such as polyethylene to the glass. Thicker layers doped with Sb or F ions are electrically conducting and used in electroluminescent devices. SnO2 has been used as pigment in the manufacture of glasses, enamels and ceramic glazes. Pure SnO2 gives a milky white colour; other colours are achieved when mixed with other metallic oxides e.g. V2O5 yellow; Cr2O3 pink; and Sb2O5 grey blue. SnO2 has been used as a polishing powder and is sometimes known as "putty powder", SnO2 is used in sensors of combustible gases. In these the sensor area is heated to a constant temperature (low 100s °C) and in the presence of a combustible gas the electrical resistivity drops. Doping with various compounds has been investigated (e.g. with CuO ). Doping with Cobalt + Manganese, gives a material that can be used in e.g. high voltage varistors. Tin dioxide can be doped into the oxides of iron or manganese.