Preparation of zinc dithionite
10 g of pure zinc powder (a grade of at least 100 mesh should be used; zinc “dust” is not suitable because of its high content of oxide) is added to 150ml of absolute alcohol contained in a 250ml filter flask fitted with a stopper and gas inlet tube leading to about one-half inch from the bottom of the flask. The mixture is saturated with sulfur dioxide at 0°C and allowed to stand at room temperature with occasional gentle swirling for about three days. By this time the solid in the flask should be pure white in color and no visible trace of zinc should remain. The slurry is filtered under an inert atmosphere, washed three or four times with 50ml of absolute alcohol, and then with two similar portions of absolute ether. During the filtration and washings zinc dithionite should be protected from atmosphere air and moisture. The obtained zinc dithionite is dried in a desciccator filled with an inert gas and stored in tightly stoppered bottles under an indifferent atmosphere. Yield is almost quantitative.
Inorganic laboratory preparations, by G. G. Schlessinger, 72-73, 1962
ZINC HYDROSULFITE, Zinc dithionite, UNII-J5XTW55OEM, Dithionous acid, zinc salt (1:1), 7779-86-4, 11085-35-1, AC1L2NHN, Dithionous acid zinc salt, J5XTW55OEM, HSDB 1055, ZINC(2+) ION DITHIONITE, EINECS 231-942-2, Zinc dithionite or zinc hydrosulfite, UN1931, IN000676, IN006317, Zincate(4-), tetrakis(monothiosulfato(2-))di-, Zinc dithionite or zinc hydrosulfite [UN1931] [Class 9]