问题 选择题

下列有关实验装置进行的相应实验,能达到实验目的的是

A.装置①可用于分离C2H5OH和H2O的混合物

B.装置②可用于蒸干NH4Cl饱和溶液制备NH4Cl晶体

C.装置③可用于制取少量纯净的CO2气体

D.装置④可用于比较碳酸钠和碳酸氢钠的热稳定性,大试管A中装碳酸钠固体,小试管B中装碳酸氢钠固体

答案

答案:D

题目分析:乙醇和水互溶,不能使用分液法分离,可用蒸馏法分离,A错误;氯化铵受热分解,加热氯化铵溶液得不到氯化铵固体,可用降温结晶法,B错误;盐酸易挥发,所以得不到纯净的二氧化碳气体且纯碱为粉末状固体,在多孔橡胶挡板上不好放置,C错误;碳酸钠直接加热也不分解而碳酸氢钠间接受热即发生分解说明稳定性碳酸钠大于碳酸氢钠,D正确。

点评:掌握常见混合物分离的方法、常见气体的制备、净化、干燥、收集、尾气处理等。

单项选择题
单项选择题

Abortion. The word alone causes civil conversation to flee the room. This is largely because the pro-choice and pro-life positions are being defined by their extremes, by those who scream accusations instead of arguments.

More reasonable voices and concerns, on both sides of the fence, are given little attention.

For example, pro-life extremists seem unwilling to draw distinctions between some abortions and others, such as those resulting from rape with an underage child. They would make no exception in the recent real-life case of a woman who discovered in her fifth month that her baby would be born dead due to severe disabilities.

On the other hand, pro-choice extremists within feminism insist on holding inconsistent positions. The pregnant woman has an unquestionable fight to abort, they claim. Yet if the biological father has no say whatsoever over the woman’s choice, is it reasonable to impose legal obligations upon him for child support Can absolute legal obligation adhere without some sort of corresponding legal rights

The only hope for progress in the abortion dialogue lies in the great excluded middle, in the voices of average people who see something wrong with a young girl forced to bear the baby of a rapist.

Any commentary on abortion should include a statement of the writer’s position. I represent what seems to be a growing "middle ground" in pro-choice opinion. Legally, I believe in the right of every human being to medically control everything under his or her own skin. Many things people have a legal right to do, however, seem clearly wrong to me. adultery, lying to friends, walking past someone who is bleeding on the street. Some forms of abortion fall into that category. Morally speaking, my doubts have become so extreme that I could not undergo the procedure past the first three months and I would attempt to dissuade friends from doing so.

Fanatics on both sides are using reprehensible and deceitful tactics. An honest dialogue on abortion must start by re-setting the stage, by denouncing the approaches that block communication.

To a pro-life extremist, ().

A. all babies should be carded to term

B. babies resulting form rape should not be born

C. deformed babies can be aborted when detected

D. an underage girl has no right to give birth