题干

小丽在购买的袋装薯片中发现有一个小袋,上面标有“成分:CaO、Fe;作用:防潮、防氧化;警告:禁止食用”等字样,撕开小袋,发现里面的固体粉末有少许是棕红色的,大多数是灰白色的.经过分析,她认为棕红色粉末是Fe2O3,灰白色粉末应该含有CaCO3和Fe,为验证自己的判断,小丽打算进行实验探究,请你一同参与.

实验目的:证实灰白色粉末中含有CaCO3和Fe.

查阅资料:①氢气具有还原性,能夺取某些金属氧化物中的氧,使金属还原,②白色的无水硫酸铜遇水变成蓝色.

实验设计:装置如图所示:

上一题 下一题 0.0难度 选择题 更新时间:2017-02-24 09:59:48

答案(点此获取答案解析)

同类题5

阅读理解

    Careers in zoology are extremely varied and unique, and can provide incredible learning and work opportunities for anyone devoted to animal studies and welfare. Zoology, or the study of animals, is a wide field with many specialties, including research, conservation, veterinary (兽医的) medicine, and the care of animals. For people with a love of animals and some training, dreams of careers in zoology may come true.

    Some careers in zoology focus on research and scientific studies. These careers may allow those with a good theoretical science background to develop and run studies that improve human understanding of the animal world. Research in zoology can help create safer and more effective products for animals or can teach humans more about animal behavior in order to aid in conservation, breeding programs, and habitat preservation.

    Careers in zoology that focus on conservation attach great importance to the continued survival and increased protection of animal species. Conservationists may work with political groups or governments to help make laws to protect and preserve animals, or may work in the field gathering information on potential threats to the health of global ecosystems. Some conservationists work in educational fields, trying to improve human efforts to save animals from extinction.

    Animals are subject to illness and injury, and some careers in zoology help to create a safe, stable animal population. Veterinary medicine is an important specialty field, and may take several years of intensive training to qualify as a certified veterinarian. While many veterinarians focus on the small-animal practice of domestic pets, vets in rural areas often work with large farm animals and more adventurous veterinarians may work with exotic species in zoos and wildlife preserves. .

    Humans love to observe animals, and modern-day zoos and wildlife preserves help meet that interest while providing facilities to assist with conservation programs. Zoology careers in zoos can range from overseeing breeding programs, to creating the proper diet for a deer, to cleaning the tiger's cage. Many volunteer and entry-level jobs are available for people that love animals.