2022 英语周报 八年级 新课程 8答案

读后续写Possible version lI stared at the paper and then looked around. I was cold. Although I could not see my sistersnor the new house, which was hidden from my sight by a grey wall, I got the feeling that I was notalone. Walking along the shore was a tall familiar figure who looked lost in his thoughts. I lookedgain at the paper in my hand, closed my eyes and wishedAs /opened my eyes, I found my father was standing right beside me. Happy birthday, sonhe said, patting my shoulder gently. I smiled up at him and took his hand. Looking back, life fromthat day on marked the start of a close bond and a strong friendship with my father. What was mybirthday surprise? Wishes do come truePossible version 2I stared at the paper and then looked around. On the backside, there was a map. I noticed thatit was clearly leading me in a direction, but who could have sent this? I stood there in silence andstudied it. I decided to follow the map and it led me down the beach until I reached a staircase. Iooked back and could no longer see my siblings. I continued to follow the point on the map, untilI unexpectedly lost my footing and fell zksq down the stepsAs I opened my eyes, I found my father was standing right beside me. Happy birthday, sonhe said, patting my shoulder gently. Then he asked how I had come upon this place? I explained tohim that I had found the bottle in the ocean and when I opened it had the words on it. Shocked bythe message, my father realized what I had found I threw this bottle into the ocean many years agowhen I was alone. he said. I used to come to this exact place to get away from everyone else. NowI get to share this experience with you. What a birthday surprise

18.(1)圆底烧瓶(1分)Na2SO3+H2SO4m=Na2S(1+SO:↑+H2O(1分)(2)调节硫酸的滴加速度(1分)(3吸收多余的SO2或H2S,防止污染环境(1分)2:1(1分)(4)取一小段pH试纸于表面皿上,用洁净的玻璃棒蘸取待测溶液点在pH试纸中段,与标准比色卡对照,读出溶液的pH(2分)(5)S,O2+4Cl+5H2O=2S(2-+10H++8Cl(1分)(6)碱式滴定管(1分)0.0024mol1.1(2分)【解析】(1)仪器A的名称为圆底烧瓶反应的化学方程式为Na2SO2+H2SO4a2SO4+SO2↑+H2O。(2)装置B的作用之一是观察SO2的生成速率,控制SO:生成速率可以通过调节硫酸的滴加速度来实现。(3)二氧化硫和硫化氢会污染环境,装置E可以吸收多余的SO2或H2S,防止污染环境;为提高产品纯度.应使烧瓶C中Na:S和NaSO3恰好完全反应,根据题干中的三个反应可以推出,2Na2S+Na2SO3+3S02=3Na:S2O,烧瓶C中Na2S和Na:SO)3物质的量之比应为2(4)常温下,用pH试纸测定0.1mol·L-1Na:S2O3溶液pH约为8,测定的具体操作为取一小段pH试纸于表面皿上、用洁净的玻璃棒蘸取待测溶液点在pH试纸中段,与标准比色卡对照,读出溶液的pH。(5)向新制氯水中滴加少量Na2S2O3溶液,氯水颜色变浅,有硫酸根离子生成,氯气被还原为氯离子,反应的离子方程式为S2O3+4Cl2+5H2O=2S0;+l0H++8C1(6)NaS2O3溶液显碱性,选用碱式滴定管;根据数据可知,数据2有较大偏差舍去,消耗NaS2O3平均体积18.02+17.98+18.00为mL=18.00mL,根据题意可得关系式6n(S2O)3)~n(Cr2O5-)~2n(Ban2+),滴定用去的Na2S2O3的物质的量为0.010mol·L-10.018L=1.8×10-4mol,所以Ba2+的物质的量为一x1.8×10-mol=6×10-5mol,25.00mL废水中Ba2+的6×10-5mol物质的量浓度为0.025L=0.0024mol·L。

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