题干

某溶液中可能含有H+、NH4+、Mg2+、Al3+、Fe3+、CO32−、SO42−、NO3中的几种。①若加入锌粒,产生无色无味的气体;②若加入NaOH溶液,产生白色沉淀,且产生的沉淀量与加入NaOH的物质的量之间的关系如图所示。则下列说法正确的是

A:溶液中的阳离子只有H+、Mg2+、Al3+

B:溶液中n(NH4+)=0.2mol

C:溶液中一定不含CO32−,可能含有SO42−和NO3

D:三种离子的物质的量之比:n(H+)∶n(Al3+)∶n(Mg2+) = 1∶1∶1

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答案(点此获取答案解析)

B

同类题4

Directions: After reading the passages below, fill in the blanks to make the passages coherent and grammatically correct. For the blanks with a given word, fill in each blank with the proper form. of the given word; for the other blanks, use one word that best fits each blank.

Ask helpful Hannah

Dear helpful Hannah,

I’ve got a problem with my husband, Sam. He bought a smart phone a couple of months ago and he took it on our recent ski vacation to Colorado, it was a great trip except for one problem. He has a constant urge____  for next messages; he checks his phone every five minutes! He’s so addicted to it that he just can’t stand the idea ____   there may be an important text. He can’t help checking even at inappropriate times like when we are eating in a restaurant and I am talking to him! He behaves____  any small amount of boredom can make him feel the need to check his phone even when he know he shouldn’t. The temptation to see ____  is connecting him is just too great. When I ask him to put down the phone and stop ____  (ignore) me, he say, “In a minute.” but still checks to see if____        has posted something new on the Internet. Our life ____ (interrupted). If we go somewhere and I ask him to have the phone at home, he suffers from withdrawal symptom. May this dependency on his smart phone has become more than an everyday problem.

   I recently read an article about “nomophobia,”____  is a real illness people can’t suffer from the fear of being without your phone! I am worried that Sam maybe suffering from this illness because he feels anxious if he doesn’t have his phone with him, even for a short time.

  Who would have thought that little devices like these could have brought so much trouble!                                                                                                                                     

Sick and Tired Sadie