A-level是英国大学入学考试,在A-level考试中有70多门科目可供选择,其中,A-level化学是常考热门科目之一,接下来,小编为大家介绍一下A-level化学备考真题演练。
The acarid mite releases Iardolure to attract other mites to a host. This chemical can be destroyed by hydrolysis with acid.
Ch3Ch2Ch2[CH(Ch3)Ch2]3CH(Ch3)O CHO
A simplified formula for lardolure may be written as follows.
RCH(Ch3)O CHO
What are the products of its hydrolysis?
A RCH(Ch3)CO2H + Ch3OH
B RCH(Ch3)CO2H + HCO2H
C RCH(Ch3)OH + CO2
D RCH(Ch3)OH + HCO2H
答案:D
在这个题中,实际上第一段话以及那个看起来很长很复杂的公式不是做题所必须的信息,我们可以直接读红色字部分(先读问题,再找its所代指的上面的公式),完全不影响作对题。答案是D,我们只要知道酯的水解,就可以轻松做对此题。
又如,9701/12/M/J/11中的第三十五个选择题,
When the yellow liquid NCl3 is stirred into aqueous sodium hydroxide,the reaction that ocurrs can be represented by the following equation.
2NCl3(l) + 6NaOH(aq) -> N2(g) + 3NaCl(aq) + 3NaOCl(aq) + 3h2O(l)
What will be the result of this reaction?
1,The nitrogen undergoes a redox reaction
2,A bleaching solution remains after the reaction
3,The final solution gives a precipitate with acidified silver nitrate
答案:A(1,2 and 3 are correct)
在做这道题时,我们完全可以不看公式上面的那两行英语,读问句以及下面的三个选项(从选项返回方程式找答案),直接作答。要知道考试是在一个小时的时间内完成40个选择题,意味着,一分半钟的时间内完成一道题,是争分夺秒的竞赛。所以这种节约时间的小技巧还是要多掌握一点儿的!