研究发现,硝酸越稀,还原产物中氮元素的化合价越低。某同学取适量的铁铝合金与足量很

题型:选择题

问题:

研究发现,硝酸越稀,还原产物中氮元素的化合价越低。某同学取适量的铁铝合金与足量很稀的硝酸充分反应,没有气体放出。在反应结束后的溶液中,逐滴加入4mol/LNaOH溶液,所加NaOH溶液的体积(mL)与产生的沉淀的物质的量(mol)的关系如图所示。

分析上述图形,下列说法不正确的是

A.OC段离子反应方程式:H+十OH-=H2O

B.溶液中结合OH-能力最强的离子是H+,最弱的离子是Al3+

C.溶液中n(NH4+)=0.012mol

D.欲测定F点沉淀的质量,实验步骤是:过滤、洗涤、干燥、称量

考点:物质的量
题型:选择题

单项选择。

Which panda is             , the big one or the small one?[ ]

A. funny

B. funnier                       

C. the funny             

题型:选择题

右图是a、b两种固体物质的溶解度曲线。下列说法中正确的是

A.a物质的溶解度受温度变化的影响较小,b物质的溶解度受温度变化的影响较大。

B.t℃时,等质量的a、b饱和溶液中含有相同质量的溶质

C.当温度大于t℃时,a溶液一定比b溶液浓

D.a中含有少量b时,用冷却热饱和溶液的方法提纯a。

题型:选择题

1879年,某项科技新成果发明的消息传到英国,伦敦证券交易所的煤气股票价格随之狂跌。引起股票狂跌的科技新成果应是下图中的[ ]

A.改良蒸汽机

B.蒸汽机车

C.汽车

D.电灯

题型:选择题

地球上71%的面积覆盖着水,水是生命之源,也是重要的溶剂,下列说法正确的是(  )

A.生石灰与烧碱溶于水都有热量放出,不能用加水的方法鉴别二者

B.溶质在溶解的过程中,有的放出热量,有的吸收热量

C.常温下KNO3、Ca(OH)2的饱和溶液降温后仍是饱和溶液

D.将NaCl、蔗糖溶于水后,溶质均以离子形式存在

题型:选择题

Democrats on the Senate Judiciary Committee vented their fury over high gasoline prices at executives of the nation’s five largest oil companies on Wednesday, grilling the oilmen over their multimillion-dollar pay packages and warning them that Congress was intent on taking action that could include a new tax on so-called windfall profits. Such showdowns between lawmakers and oil titans have become a familiar routine on Capitol Hill. But with gas prices nearing $ 4 a gallon, and lawmakers headed home for a weeklong Memorial Day recess where they expect to get an earful from angry constituents, there is added urgency for Congress to appear active.

But while momentum is building for several measures, including a bill that would allow the Organization of the Petroleum Exporting Countries to be sued in American courts under antitrust laws, there is little sign that any of the proposals would do much, if anything, to lower prices quickly. And the oil executives warned that government intervention might only make things worse. Instead, they called on Congress to allow more drilling and exploration for domestic oil.

The increasing urgency to seem aggressive about gasoline prices was apparent on Tuesday when the House voted by an overwhelming 324 to 84 to approve the bill, commonly referred to as NOPEC, which classifies OPEC as a monopoly in violation of the Sherman Antitrust Act. Senate Democrats have included that measure as part of a package of legislation intended to address the high price of gasoline, along with the tax on windfall profits and a measure to tamp down speculation in the oil futures market that many lawmakers think is contributing to the run-up in prices.

At the Judiciary Committee hearing, Democratic senators struggled to have the executives explain how oil prices had risen so high. The senators expressed doubt that basic laws of supply and demand were at work and suggested instead a more sinister combination of monopolistic behavior by oil-producing countries, speculation in the futures markets and sheer corporate greed.

On Monday, President Bush signed a bill temporarily suspending the purchase of crude oil for the nation’s Strategic Petroleum Reserve. Mr. Bush had initially opposed such action but relented after the House and Senate approved the bill by wide margins. Senator Richard J. Durbin, Democrat of Illinois and a p supporter of Senator Baraek Obama’s presidential bid, made a particularly pointed attack, in which he seemed to warn the oil executives that they would soon no longer have such a good friend in the White House. He also suggested that Mr. Bush should be doing more to press the oil companies to help lower prices at the pump, while acknowledging that it would be difficult to pass a windfall profits tax while Mr. Bush was still in office.

From the text we can learn that the bill allowing OPEC to be sued under antitrust laws()

A. handicaps more drilling and exploration for domestic oil

B.is a kind of government intervention that only makes things worse

C. turns out to be less influential to decrease oil price rapidly

D.is in violation of the Sherman Antitrust Act

更多题库