听力原文:F: I'm going to the snack bar for a cup of coffee. Would you like me to bring you back something? M: Not from the snack bar. But could you pick up a paper for me? Q: What does the man mean? (19)
A.
He dislikes food from the snack bar.
B.
He doesn't need anything.
C.
He asks the woman to buy a newspaper for him.
D.
He will go with the woman and hand in his term paper.
【简答题】(8分)难溶电解质在水溶液中存在着电离平衡。在常温下,溶液里各种离子的浓度以它们化学计量数为方次的乘积是一个常数,叫溶度积常数( K sp )。 例如:Cu(OH) 2 Cu 2 + +2OH - , K sp = c (Cu 2 + )· c 2 (OH - )=2×10 -20 。当溶液中各种离子的浓度方次的乘积大于溶度积时,则产生沉淀,反之固体溶解。 (1)某CuSO 4 溶液里 c (Cu...