问题 单项选择题

中国药典用银量法测定苯巴比妥的含量,指示终点的方法是

A.铬酸钾法
B.铁铵矾指示剂法
C.吸附指示剂法
D.电位法
E.永停法

答案

参考答案:D

解析: 本题考查苯巴比妥含量测定方法。
巴比妥类药物在合适的碱性溶液中,可与银离子定量成盐。在滴定过程中,巴比妥类药物首先形成可溶性的一银盐,当被测定的巴比妥类药物完全形成一银盐后,稍过量的银离子就与巴比妥类药物形成难溶性的二银盐沉淀,使溶液变浑浊,以显示终点。但是这种显示终点方法不灵敏,故采用银-玻璃电极系统点位法指示终点。见中国药典05版:用甲醇作溶剂,银-玻璃电极系统电位法指示终点。

阅读理解

Peter wondered why he didn't have many friends. The reason(原因)was he was always taking, never giving. One day Peter told Bill, "I'd like to give a party on Saturday, I'd like you to come and bring Martha, too." "Thanks, Peter. We' d be happy to come." " Perhaps you'd like to bring your violin. You and Martha sing well together. I'm sure everyone will want you to sing for us." That was how Peter began to plan his party. Next he asked another friend, Betty, to bring a cake. "You make the best cake in the world, Betty, and I like to eat your cake better than have one from the bakery." Peter invited(邀请)a few other friends to come to his party. He didn't forget(忘记)to ask something from each one of them. He even asked Jim and Mary Jackson to let him give the party at their house! They agreed(同意). The party was a big success(成功). However, as the guests(客人)were leaving, they said "Thank you" to Bill and Martha for the music, Betty for the cake, the Jacksons for the use of the house and to others for their hard work. To Peter they just said, "Thanks for the invitation(邀请)."

小题1:The party was held(举行)          .

A.at Peter's house

B.in a large hall(大厅)

C.at Peter's friend's house

D.in a secret(秘密的)place小题2: Which of the following is NOT TRUE?

A.Betty made the best cake.

B.Mary Jackson sang well.

C.Bill played the violin well.

D.The Jacksons did hard work for the party.小题3:          liked Peter.

A.Many of his friends

B.Few people

C.Everyone

D.All his friends小题4:Peter         to give the party.

A.tried his best

B.did nothing

C.only invited some friends

D.did everything小题5:From the story, we can see Peter was                .

A.a warm -hearted(热心的)man

B.good at making friends

C.a selfish(自私的)man

D.a welcomed(受欢迎的)friend

名词解释