（15分）Ⅰ.在一个容积固定为2L的密闭容器中，发生反应：aA (g) + bB(g) pC(g) △H=?反应情况记录如下表：

(1)第2min到第4min内A的平均反应速率V(A)=                mol•L^－1• min^－1

(2)由表中数据可知反应在第4min到第6min时处于平衡状态，若在第2min、第6min、第8 min时分别改变了某一个反应条件，则改变的条件分别可能是：

①第2min                            或                                  ；

②第6min                                      ；

③第8 min                                     。

(3)若从开始到第4 min建立平衡时反应放出的热量为235.92kJ则该反应的△H=       。

(4)反应在第4 min建立平衡，此温度下该反应的化学平衡常数K=              .

Ⅱ.已知：常温下，A酸的溶液pH＝a, B碱的溶液pH＝b

(1)若A为盐酸，B为氢氧化钡，且a=3,b=11,两者等体积混合，溶液的pH为              。

A．大于7              B.等于7            C. 小于7

(2)若A为醋酸，B为氢氧化钠，且a=4,b=12，那么A溶液中水电离出的氢离子浓度为

            mol•L^－1，B溶液中水电离出的氢离子浓度为             mol•L^－1。

(3)若A的化学式为HR，B的化学式为MOH，且a+b=14,两者等体积混合后溶液显碱性。则混合溶液中必定有一种离子能发生水解，该水解反应的离子方程式为：

                                                             。

"It’s no use, Mum," said Johnny. "I’m just no good at dancing."

"You’ve got to keep trying. Tonight will be (1) , dear. Try a turn with that pretty Lisette. "

Johnny (2) . Every Saturday night used to be the best of the week. He and his parents went to the (3) at the Club, where his hero, Alcide, played the accordion with the band. But lately everything had changed. Now that Johnny was older, he was (4) to dance with a girl!

(5) Johnny and his parents arrived at the Club, music had already started. Johnny got up his (6) to approach Lisette. "May I have this dance" Johnny asked. "That’s all right."said Lisette. Johnny struggled to keep up with Lisette’s (7) steps, but he was always one beat behind her. Then Johnny heard his friend Pierre say, "Look! Johnny has two left feet!" (8) burst from the crowd. Johnny (9) and ran outside, determined never to go to another dance.

The next Saturday, Alcide (10) to Johnny’s house for some potatoes. He happened to hear Johnny playing the accordion. Alcide’s eyes (11) . "Bring that accordion and play some songs tonight," Alcide said. Then he drove off, leaving Johnny staring open mouthed (12) him.

At the Club, Johnny scanned the crowd for Lisette and (13) her. The band played for a long time before Alcide said, "Dear friends, I got a (14) for you tonight. Young Johnny is going to join us!" (15) , Johnny stepped up on the platform, his eyes on the floor. He began to play, and the band (16) behind him. When the song ended, he heard cheers. Johnny kept playing until the dance was (17) . "You did a fine job tonight. Play with us again next Saturday night, " Alcide said. "Yes, sir! " said Johnny. (18) he went outside, Johnny saw Lisette and her friends near the door. Lisette stepped (19) , smiling. "You played really good tonight!" she said."Thank you," Johnny blushed. As he walked on, Pierre (20) moved out of the way for him to pass.Johnny patted his accordion. Come to think of it, in his whole life, he had never once seen Alcide out on the dance floor.

9().

A．broke away

B．went out

C．broke up

D．turned out