Which of the following group II compounds is used in medicine as an antacid?
- A. Barium sulphate
- B. Magnesium hydroxide
- C. Calcium carbide
- D. Beryllium chloride
Explanation
Magnesium hydroxide, sold as milk of magnesia, is a weak insoluble base that neutralises excess stomach acid without being absorbed in quantity. Barium sulphate is also used medically but as a contrast medium for X rays, and it is safe only because it is so insoluble that the toxic barium ions are not released. Beryllium compounds are highly toxic.