问题 填空题

肥皂的主要成分为硬质酸钠(C12H25COONa),它是一种有机酸的钠盐,在肥皂水中滴入盐酸会出现白色沉淀,这沉淀物是______(写名称);若在肥皂水中加入硬水(含Ca

 2+ 
、Ng
 2+ 
)也会出现白色沉淀,试写出生成沉淀的离子方程式(离子方程式是指用实际参加反应的离子来表示反应过程的式子,如氢氧化钠与盐酸反应的离子方程式是:H++OH-=CO2)(任意写一条):______.

答案

解;因肥皂的主要成分为硬脂酸钠,其化学式为C12H25COONa,在肥皂水中滴入盐酸会反应生成不溶于水的硬脂酸和氯化钠,则观察到白色沉淀是硬脂酸;

若肥皂水中加入硬水,则会反应生成不溶于水的硬脂酸钙、硬脂酸镁沉淀,反应的离子方程式为:2C12H25COO-+Ca2+=(C12H25COO)2Ca↓或者2C12H25COO-+Mg2+=(C12H25COO)2Mg↓;

故答案为:硬脂酸;2C12H25COO-+Ca2+=(C12H25COO)2Ca↓或者2C12H25COO-+Mg2+=(C12H25COO)2Mg↓.

单项选择题
单项选择题

Beyond question, Clinton was supposed to close up, stay out of sight, and avoid second- guessing his wife’s boss. After his ego blustered into oncoming traffic during Hillary’s heated primary race (1) Obama, the nation suffered from yet another turn of Clinton fatigue.

(2) this week Bill Clinton showed an instinct for robust, inclusive leadership that the (3) White House occupant could make good use of right for the time being. With President Obama struggling to (4) the political damage from the Gulf oil spill, Clinton not only can’t help himself—he’s worth being listened.

The conventional-wisdom (5) on President Obama’s early reaction to the spill was (6) he didn’t emote enough. He didn’t feel the (7) of all those people in the crisis whose livelihood would be destroyed, whose clean waters and wildlife would be (8) in black gunk.

Clinton considers this is an unfair (9) but offers a different—and more pointed— lesson to his young successor. "I think we ought to (10) in the same boat for a while... Let’s just (11) the problem, and then we can hold everybody responsible and emote or not emote, " Clinton conversed (12) CNN Anchor Wolf Blitzer.

Obama’s first (13) after the oil spill was to "feel the blame" rather than "feel the pain, " which are pretty sarcastic words as it were. No one intends to let British Petroleum (BP) management (14) the hook—for dangerously cutting corners, and for a (15) safety record. However, the President’s (16) focus on scolding BP consumed (17) White House energy while the oil gushed.

Great leaders don’t rush to criticise; Instead they instinctively (18) solutions. Rudy Giuliani, who didn’t stop to blame (19) intelligence for letting it happen, stood out from New York mayor with a girlfriend problem to 9/11 hero when he took control of a crisis and instilled confidence that a ravaged city could (20) beyond a terrorist attack.

8()

A.driven

B.shunned

C.drowned

D.killed