问题 选择题

下列实验方法正确的是                                         (   )

A.除去氧化钙中少量的碳酸钙:加稀盐酸

B.鉴别稀盐酸、氯化钠溶液和氢氧化钙溶液:加入碳酸钠试液,观察现象

C.鉴别碳酸钠溶液和氢氧化钙溶液:加入酚酞试液,观察颜色变化

D.鉴别化肥氯化钾、氯化铵:加熟石灰,研磨,闻气味

答案

BD

题目分析:A 氧化钙和碳酸钙均可以和稀盐酸反应;B 碳酸钠和稀盐酸反应有二氧化碳气体生成,和氢氧化钙反应有白色碳酸钙沉淀生成,和氯化钠不反应,无明显现象;C 碳酸钠溶液和氢氧化钙溶液均显碱性,均可使酚酞变红;D 氯化钾加熟石灰,研磨,闻气味没有明显现象,而氯化铵中加熟石灰,研磨,闻气味会有刺激性气味生成,因为反应有氨气生成。

点评:对于常见化学物质的鉴别属于中考的必考点,选择填空均可出题,考察形式较为灵活,注意积累总结。

单项选择题

When Harvey Ball took a black felt-tip pen to a piece of yellow paper in 1963, he never could have realized that he was drafting the face that would launch 50 million buttons and an eventual war over copyright. Mr. Ball, a commercial artist, was simply filling a request from Joy Young of the Worcester Mutual Insurance Company to create an image for their "smile campaign" to coach employees to be more congenial in their customer relations. It seems there was a hunger for a bright grin-the original order of 100 smiley-face buttons were snatched up and an order for 10,000 more was placed at once.
The Worcester Historical Museum takes this founding moment seriously. "Just as you’d want to know the biography of General Washington, we realized we didn’t know the comprehensive history of the Smiley Face," says Bill Wallace, the executive director of the historical museum where the exhibit "Smiley-An American Icon" opens to the public Oct. 6 in Worcester, Mass. Worcester, often referred to by neighboring Bostonians as "that manufacturing town off Route 90," lays claim to several other famous commercial firsts, the monkey wrench and shredded wheat among them. Smiley Face is a particularly warm spot in the city’s history. Through a careful historical analysis, Mr. Wallace says that while the Smiley Face birthplace is undisputed, it took several phases of distribution before the distinctive rounded-tipped smile with one eye slightly larger than the other proliferated in the mainstream.
As the original buttons spread like drifting pollen with no copyright attached, a bank in Seattle next realized its commercial potential. Under the guidance of advertising executive David Stern, the University Federal Savings & Loan launched a very public marketing campaign in 1967 centered on the Smiley Face. It eventually distributed 150,000 buttons along with piggy banks and coin purses. Old photos of the bank show giant Smiley Face wallpaper.
By 1970, Murray and Bernard Spain, brothers who owned a card shop in Philadelphia, were affixing the yellow grin to everything from key chains to cookie jars along with "Have a happy day." "In the 1970s, there was a trend toward happiness," says Wallace. "We had assassinated a president, we were in a war with Vietnam, and people were looking for [tokens of] happiness. [The Spain brothers] ran with it. "
The Smiley Face resurged in the 1990s. This time it was fanned by a legal dispute between Wal-Mart, who uses it to promote its low prices, and Franklin Loufrani, a Frenchman who owns a company called SmiteyWorld. Mr. Loufrani says he created the Smiley Face and has trademarked it around the world. He has been distributing its image in 80 countries since 1971.
Loufrani’s actions irked Ball, who felt that such a universal symbol should remain in the public domain in perpetuity. So in a pleasant proactive move, Ball declared in 1999 that the first Friday in October would be "World Smile Day" to promote general kindness and charity toward children in need. Ball died in 2001.
The Worcester exhibit opens on "World Smile Day", Oct. 6. It features a plethora of Smiley Face merchandise—from the original Ball buttons to plastic purses and a toilet seat— and contemporary interpretations by local artists. The exhibit is scheduled to run through Feb. 11.

Which of the following is NOT true about the "World Smile Day"

A.It was established to commemorate the founder Harvey Ball.

B.It was to promote general kindness and charity toward children in need.

C.It was declared by Harvey Ball in 1999.

D.It was decided to be held on the first Friday in October each year.

单项选择题