近年来地质、环境灾难频频发生，为防止在大灾之后疫病流行，灾区_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题填空题

近年来地质、环境灾难频频发生，为防止在大灾之后疫病流行，灾区需要大量的各种消毒剂、漂白剂等。

(1)二氧化氯是目前国际上公认的第四代高效、无毒的广谱消毒剂，它可由KClO₃与SO₂在H₂SO₄作用下反应制得。请写出反应的离子方程式：。

(2)过碳酸钠是一种新型固态漂白剂，化学式可表示为Na₂CO₃·3H₂O₂，它具有Na₂CO₃和H₂O₂的双重性质。过碳酸钠与下列物质均会发生化学反应而失效，其中过碳酸钠只发生了氧化反应的是。

A．MnO₂

B．KMnO₄溶液

C．稀盐酸

D．Na₂SO₃溶液(3)漂白剂亚氯酸钠(NaClO₂)在常温下黑暗处可保存一年，HClO₂不稳定可分解，反应的离子方程式为HClO₂―→ClO₂↑＋H^＋＋Cl^－＋H₂O(未配平)。当1 mol HClO₂分解时，转移的电子数是。

答案

(1)2ClO₃^－＋SO₂=2ClO₂＋SO₄²^－　(2)B　(3)0.8×6.02×10²³(或4.816×10²³)

(1)ClO₃^－被SO₂还原为ClO₂，SO₂被ClO₃^－氧化为SO₄²^－，其离子反应方程式为：2ClO₃^－＋SO₂=2ClO₂＋SO₄²^－。(2)Na₂CO₃·3H₂O₂反应时，与氧化还原反应相关的是H₂O₂，H₂O₂被MnO₂催化分解生成H₂O、O₂，过碳酸钠既发生氧化反应也发生还原反应；KMnO₄溶液具有强氧化性，能将H₂O₂氧化生成O₂，过碳酸钠中H₂O₂只发生氧化反应；Na₂SO₃被H₂O₂氧化，过碳酸钠中H₂O₂发生还原反应；过碳酸钠与稀盐酸不发生氧化还原反应。

(3)配平反应：5HClO₂=4ClO₂↑＋H^＋＋Cl^－＋2H₂O，5 mol HClO₂分解转移4 mol电子，故1 mol HClO₂发生分解反应，转移0.8 mol电子，即数目为0.8×6.02×10²³。

完形填空

Last Christmas while staying with my parents, I        across some old love letters that my parents wrote to each other. These letters were all pilled up in a basket, dirty and       With dust.      to read and sort them, I asked them if I could take the letters back to my Illinois home. They agreed.
As I carefully opened each letter, all of them         with age, I discovered a new page      unknown to me in this private chapter of my parents' lives.
My father used to        in the army. So his letters were full of frontline       of the things about the war. Each of my mother's letters was marked with her 1944 dark red lipstick kiss. I was        to these letters like a magnet (磁铁).
Just six weeks after our Christmas visit, Daddy became very      . and was hospitalized. This time, he was fighting a      . kind of war. As I sat by his bedside, we discussed the        . He told me how much receiving those lipstick-kissed letters had        to him when he had been so far from home.
It so happened that the next day would he February 14. From the        letters I chose the card my father had sent Mother in 1944 and brought it to my father's bedside.
At his bedside, I joked with him, saying      , "Today is Valentine's Day, don't you want to send Mother a present?" He became more           when I handed him the old       . He carefully opened it and took out the card, and when he       it, his eyes were filled with tears.
My father, in a voice tight with       read the loving         he'd sent to my mother fifty-six years earlier. And this time, he could read it to her         .
小题1:A came               B. hit             C. drew                D. fell

D．occasionally

C．introductions

D．occupations

B．traditional

D．prescriptions

小题12:A. meant B. intended C, planned D. said

B．enthusiastic

A．Christmas card

A．astonishment

单项选择题

投影线或投影方向垂直于投影面的投影称为（）投影法。

A、中心

B、正

C、斜

D、平行