题干

现有一包铝热剂是铝粉和氧化铁粉末的混合物,在高温下使之充分反应,将反应后的固体分为两等份,进行如下实验(计算pH时假定溶液体积没有变化):
①向其中一份固体中加入100mL 2.0mol·L1的NaOH溶液,加热使其充分反应后过滤,测得滤液的pH=14;
②向另一份固体中加入100mL 4.0 mol·L1的HCl溶液,使固体全部溶解,测得反应后所得溶液中只有H+、Fe2+和Al3+三种阳离子且pH=1。
则②产生气体的体积(标准状况)为(   )

A:2.352L

B:2.448L

C:2.688L

D:2.856L

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答案(点此获取答案解析)

D

同类题2

阅读下列短文, 从每小题所给的A、B、C、D四个选项中, 选出最佳选项.

    For too many, the damage begins early in life. Four out of 10 babies born in the United States do not form a strong relationship with either parent, and they will pay for that the rest of their lives.

    New research from Princeton University confirms what other researchers have already found: The number of babies born into families that are too poorly equipped(装备、配备) to give them a fair chance of having a successful life is very big.

    That finding is supported by many other research Projects, including a study from the University of Rochester showing that nearly one-third of U.S. parents don't know what to expect from their new horns, or how to help them grow and learn and get along with others. Babies, as others have pointed out, don't come with an owner's manual.

    The basic problem, according to the Princeton study, is 40 percent of infants in the U.S. live in fear or distrust of their parents, and that will turn into aggressiveness(侵犯), defiance(挑衅) and hyperactivity(多动) as they grow into adults.

    Of that number, 25 percent don't have a close relationship with their parents because the parents don't satisfy their needs. And 15 percent find their parents so troubling that they will avoid them whenever possible.

    That will not necessarily result in a lifetime of violence(暴力), but it will make living a successful life much more difficult.

"They can overcome(克服) it," sociologist (社会科学家) Sophie Moullin of Princeton, lead author(作者) of that study, said in a telephone interview. "It's not a make or break situation, but they might find it harder to control their behavior."

    Moullin, along with coauthors from Columbia University and the University of Bristol in England, analyzed(分析) more than 100 research projects, to reach their conclusions.

    There are many factors, including poverty(贫穷), ignorance(无知), and stress among parents who are so busy with their own problems that a new child is sometimes more than they can deal with.

    Yet strong relationships, the researchers say, are amazingly simple to achieve.