It is a colorless crystalline solid. It is a reducing agent. It is poisonous to mollusks like clams and oysters. It reacts with water to make tin(II) oxide hydrate, which is white, and hydrochloric acid. That is why tin(II) chloride is normally dissolved in hydrochloric acid. It reacts with oxygen in the air to make tin(IV) chloride and tin(IV) oxide. It reacts with silver and gold compounds to make silver and gold metal. It also reacts with ferric compounds to make ferrous compounds.
It reacts with bases to make tin(II) oxide hydrate, which is white; if more base is added, the tin(II) oxide hydrate dissolves to make a clear solution again.
It is used to electroplate tin on steel. It is used in the coloring of textiles. It is used to make silvered mirrors. A certain plastic uses it as a catalyst. It was used as a test for mercury(II) ions. If it is added to a colorless solution of mercury(II), a white solid of mercury(I) would form. If more is added, a black solid of mercury metal would be made. It turns bright purple in a solution that has gold ions in it. It is used in organic chemistry as a reducing agent.