题目

酚酞的结构简式如图，下列关于酚酞的说法一定正确的是 A. 酚酞的分子式是C20H12O4 B. 分子中的碳原子不在同一平面 C. 1 mol酚酞最多可消耗2 mol NaOH D. 常温下，由水电离的c（H+）=10-13mol·L-1的溶液中滴入酚酞试液后，溶液呈红色 答案：【答案】B 【解析】 分析：A、根据结构简式书写分子式；B、根据有机物分子结构判断原子共面问题；C、根据官能团判断有机物性质；D、根据分子结构判断酸性强弱。 详解：A、酚酞的分子式是C 20 H14O4 ，选项A错误；B、每个苯环中的碳原子在一个平面上，但是据有甲烷结构的碳原子可定和它们不共面Some years ago on a hot summer day in south Florida a little boy decided to go for a swim in the old swimming lake behind his house. In a hurry to dive into the cool water, he ran out the back door, leaving behind his shoes, socks, and shirt as he went. He flew into the water, not realizing that as he swan toward the middle of the lake, an alligator(鳄鱼) was swimming toward the shore. His mother in the house was looking out the window and saw the two as they got closer and closer. In extreme fear, she ran toward the water, yelling(大叫) to her son as loudly as she could. Hearing her voice, the little boy became alarmed and made a U-turn to swim to his mother. It was too late. Just as he reached her, the alligator reached him. From the dock(码头)，the mother grabbed her little boy by the arms just as the alligator snatched(夺取) his legs. That began an incredible tug-of-water(拔河). The alligator was much stronger than the mother, but the mother was much too passionate(有感情的). A farmer happened to drive by, took aim and shot the alligator. After weeks and weeks in the hospital, the little boy survived. The newspaper reporter asked if he would show him his scars(伤疤). The boy lifted his legs, then, with obvious pride, he said to the reporter, “but look at my arms. I have great scars on my arms, too. I have them because my mum wouldn’t let go. ” Some scars have caused us deep regret, but some scars are because of love. 1.From the second paragraph we can infer that_____. A．A child shouldn’t swim in the water by himself. B．We’d better grasp some skills to protect ourselves C．We should make enough preparations before swimming D．We are enjoying ourselves but don’t know the enemy is coming. 2.The incredible tug-of-water is between _______. A．The boy and the alligator B．the boy and the mother C．The alligator and the mother D．the alligator and the farmer. 3.Which of the following statements is true? A．The alligator was killed by a hunter. B．There’re scars both on the boy’s arms and legs. C．The mother was calm when seeing the alligator. D．The mother won the “match” because of her strength. 4.Why was the boy proud when he showed the scars on his arms？ A．He survived luckily. B．He was a child of God. C．He was injured slightly. D．He was proud of the scars of love.