问题 选择题

下列各组物质发生化学反应时,由于反应物的量不同而导致生成不同产物的是( )

①CO2与NaOH溶液

②盐酸溶液与偏铝酸钠

③NaHCO3溶液与盐酸

④C与O2

⑤AlCl3溶液与氢氧化钠溶液

A.除③外

B.除②外

C.除②③⑤外

D.除②⑤外

答案

答案:A

题目分析:①NaOH量固定,与少量二氧化碳反应生成碳酸钠,与过量二氧化碳生成碳酸氢钠,②盐酸少量则生成氢氧化铝沉淀,过量则生成铝离子,③与量无关,④氧气少量生成一氧化碳,过量生成二氧化碳,⑤氢氧化钠少量生成氢氧化铝沉淀,过量生成偏铝酸钠,所以答案选A。

单项选择题
单项选择题

The International Whaling Commission’s (IWC) decision to retain its ban on whaling does not mean that the killings will stop. Quite the (1) .

Save the Whale. It’s a phrase which became annoying with (2) , an unfavorable shorthand for liberal consciences. How appalling, then, that in the year 2010, it should be pressed (3) service again, to fight the whaling nations: Norway and Iceland, who exempted themselves from the 1986 prohibition (4) by the IWC, and Japan, which hunts whales under cover of " (5) research".

I am completely (6) by this week’s events in Morocco, where talks broke down. In my heart, I agree with those who have (7) the news that this year’s negotiations of the IWC have broken up, and (8) the prohibition would not be lifted (as the US proposed in a desperate (9) to break the deadlock). Yet reason (10) something else. If we do not (11) some kind of new control, the (12) will be able to go on with their slaughter (13) . Membership of the IWC is (14) , and the ban was only ever intended to be (15) . Japan, which has been buying the votes of nations with no interest in whaling (only in the 16 Japan offers in turn), will continue to press its case, having invested millions of dollars in its (17) . Geoffrey Palmer, New Zealand’s Commissioner at the IWC, has proposed a year-long (18) period. In the meantime, more whales will die.

We stand at a crossroad for whales. We see the (19) existence of these animals as an indicator of ecological threat. As symbols of an endangered world, they evoke, and provoke, a feeling that they have the same qualities as human on a scale equal to their size and supposed (20) . To some this is so much sentimental words in the New Age.

11()

A.exert

B.carry

C.punish

D.refuse