题干

向一定量的Fe、FeO、Fe2O3、Fe3O4的混合物中加入150mL 4mol•L﹣1的稀硝酸恰好使混合物完全溶解,放出2.24L NO(标准状况),往所得溶液中加入KSCN溶液,无红色出现.若用足量的H2在加热条件下还原相同质量的混合物,所得到的铁的物质的量为

(  )

A:0.21mol

B:0.25mol

C:0.3mol

D:0.35mol

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B

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    For many years, Bruce Bexler dreamed of going to the lands no human had explored and discovered rare, unknown species. That might sound like an impossible dream, but Bexler turned it into a reality.

    In December 2015, he, together with a team of Australian and American scientists, adventured into a rain forest on the island of New Guinea. They were the first people ever to enter the region. “As we were dropped on the ground by helicopter, we found no trails anywhere; it was really hard to get around,” Bexler says.

    Within minutes of landing, the team spotted a black chicken-like bird. The scientists soon determined that the creature was a type of honeyeater-the first new bird species to be sighted on New Guinea in 60 years. The honeyeater wasn't the only surprise for them. They discovered more than 40 previously unknown plant and animal species. “We were like kids in a candy store?' Bexler recalls. “Everywhere we looked, we saw amazing things we had never seen before.”

    The new found species didn't shy away from the scientists. Two long-nosed echidnas even let the visitors pick them up and take them back to camp to study them. Bexler thinks the animals weren't scared because they had never seen humans before. He explains, “This area gives scientists a place where they can study the behaviours of animals that have not yet learned to be afraid of people.”

    Bexler and his team did not have enough time to study the area completely. “We just scratched the surface, Bexler says. “Anyone who goes there will come back with a mystery.”