X-rays, barium sulfate

Barium sulfate is a useful white pigment, particularly in the precipitated form, blancfixe. It is used as a filler for paper, rubber, linoleum, and oilcloth. Because of its opacity to x-rays, barium sulfate, in a purified form, is important in contour photographs of the digestive tract. 

If a patient experiencing digestive problems needs a series of gastrointestinal X rays taken, they frequently must drink what is called a "barium cocktail." It consists of a thick suspension of barium sulfate in water, which is used because barium sulfate is opaque to X rays, and the thick suspension coats the walls of the digestive tract and makes them more visible on the X rays. Barium sulfate may be prepared in the laboratory by mixing a solution of barium chloride with a solution of sodium sulfate, which produces solid barium sulfate suspended in a solution of sodium chloride. Write the unbalanced chemical equation for this process. 

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