题目

VL Fe2(SO4)3溶液中含有a g Fe3+，取此溶液0.5VL，用水稀释至2VL，则稀释后溶液中SO42－的物质的量的浓度为( )A. B. C. D. 答案：【答案】A【解析】ag Fe3+的物质的量为： = mol，取出的0.5VL溶液中含有Fe3+的物质的量为：× = mol，稀释过程中溶质的物质的量不变，则稀释后溶液中SO42－的物质的量为：mol× = mol，稀释后溶液中硫酸根离子的浓度为：mol÷2VL＝，故答案选A。阅读下列短文，从每题所给的四个选项中选出最佳选项。 　　Before World War Ⅱ Chicago，Illinois，standing at the southern end of huge Lake Michigan，had the reputation（名声）of being one of the toughest，most lawless and corrupt（腐败的）cities in the world．It earned its ill reputation largely from those who sold strong during the days of 1919 to 1933，when a law forbade（禁止）Americans to make or sell strong wine in any form． 　　Chicagoans have a great pride in their city．They say it is of great importance to the nation than New York．It is the center of American commerce（商业）and transportation．O'Hare Airport is the busiest airport in the world．44 million passengers pass through it every year，and there are 2000 take-offs and landings every day． 　　Chicago is also a great inland port（港）．It can send goods by oceangoing ships all the way to Europe via the Great Lakes and the Saint Lawrence Seaway．It can send goods by barge（驳船），through water way and canals，to the Mississippi and down it to the Gulf of Mexico． 1．Which of the following diagrams（图解）gives the correct relationship between Lake Michigan，Chicago and Illinois？ [　　] A．B． C．D． L．M＝Lake Michigan　　Ch＝Chicago　　Ⅲ＝Illinois 2．According to the passage，Chicago is more important than New York because ________． [　　] A．Chicagoans love their city more than others B．Chicago is the center of America C．Chicago is an inland port has O'Hare Airport D．Chicago lies at the southern end of Lake Michigan 3．44 million passengers each year and 2 000 take-offs and landings prove that O'Hare Airport is ________． [　　] A．the only one in America B．the biggest one in the world C．the busiest one in the world D．the most well-known one in the world 4．If we carry goods to Chicago from Mexico，we probably go through ________． [　　] A．the Gulf of Mexico-Mississippi-Canals-Waterway-Chicago B．the Gulf Mexico-Mississippi-the Great Lakes-ChicagoC．Lake Michigan-the Saint Lawrence Seaway-the Gulf of Mexico D．Waterway－Mississippi-the Gulf of Mexico