A.33%                         B.66%                          C.78%                         D.88%

A.33%               B.66%               C.78%                   D.88%

把1 g含脉石（SiO₂）的黄铁矿样品放在O₂流中灼烧，反应完全后得到残渣0.78 g，则此黄铁矿的纯度是

1. A.
   33%
2. B.
   66%
3. C.
   78%
4. D.
   88%

A.33%                         B.66%                        C.78%                        D.88%