A:SO2能使酸性KMnO4溶液迅速褪色
B:可以用澄清石灰水鉴别SO2和CO2
C:硫粉在过量的纯氧中燃烧可以生成SO3
D:少量SO2通过浓的CaCl2溶液能生成白色沉淀
已知长方形的面积为48 ,若它的长比宽多2cm,则它的宽为( )
选择合适操作或仪器的序号填空:
①滴管 ②加热 ③坩埚钳 ④试管 ⑤检查气密性
—Are you going to buy a new camera?—Yes. But there are so many cameras that I can't decide______________.