问题 阅读理解

阅读短文,判断正(T)误(F)。

       Mr and Mrs Brown lived in a small house near London with their child. Sometimes Mr Brown came back

home from work very late, when his wife and the child were asleep, and he opened the front door of his house

with his key and came in very quietly.

       But one night when he was coming home very late, he lost his key, so when he got to his house, he rang

the bell. Nothing happened. He rang it again. Again nothing happened. Mr Brown knocked at the bedroom

window, he spoke to his wife, he shouted, but she didn't wake up. At last he stopped and thought for a few

seconds. Then he began to speak like a small child. "Mother!" he said, "I want to go to the lavatory (厕所)!" He

spoke very quietly but at once Mrs Brown woke up. Then he spoke to her and she opened the door for him.

( ) 1. The Browns lived far from London.

(     ) 2. Mr Brown rang the bell and knocked at the window one night because he came home late.

(     ) 3. Mr Brown said "Mother" like a child to wake up his wife.

(     ) 4. Mrs Brown didn't want his husband to come into their bedroom.

(     ) 5. Mrs Brown woke up at once because she heard her husband say "Mother" like her child.

答案

1-5: FFTFT

选择题
填空题

二氧化氯(ClO2)可用于自来水消毒。以粗盐为原料生产ClO2的工艺主要包括:①粗盐精制;②电解微酸性NaCl溶液;③ClO2的制取。工艺流程如下图:

(1)粗食盐水中含有Ca2+、Mg2+、SO42-等杂质。除杂操作时,往粗盐水中先加入过量的试剂X,X是         (填化学式),至沉淀不再产生后,再加入过量的Na2CO3和NaOH,充分反应后将沉淀一并滤去。经检测发现滤液中仍含有一定量的SO42-,其原因是                   。(已知:Ksp(BaSO4)=1.1×10-10;Ksp(BaCO3)=5.1×10-9

(2)上述过程中,将食盐水在特定条件下电解得到的氯酸钠与盐酸反应生成ClO2。电解时生成的气体B是             ;反应Ⅲ的化学方程式为                    

(3)ClO2很不稳定,需随用随制,产物用水吸收得到ClO2溶液。为测定所得溶液中ClO2的含量,进行了以下实验:

步骤1:准确量取ClO2溶液10.00 mL,稀释成100 mL试样。

步骤2:量取V1mL试样加入到锥形瓶中,调节试样的pH≤2.0,加入足量的KI晶体,摇匀,在暗处静置30分钟。(已知:ClO2+I+H+—I2+Cl+H2O 未配平)

步骤3:以淀粉溶液作指示剂,用c mol·L-1Na2S2O3溶液滴定至终点,消耗Na2S2O3溶液V2 mL。(已知:I2+2S2O32-=2I+S4O62-

① 准确量取10.00 mL ClO2溶液的玻璃仪器是                      

② 滴定过程中,至少须平行测定两次的原因是                        

③ 根据上述步骤可计算出原ClO2溶液的物质的量浓度为  mol·L-1(用含字母的代数式表示)。