问题 选择题

下列实验操作与实验目的相符的是(     )

序号实验操作实验目的
A测定HF、HCl的熔点、沸点比较F、Cl的非金属性强弱
BMgSO4、Al2(SO4)3溶液中分别滴加足量氨水比较镁、铝的金属性强弱
C将SO2气体通入碳酸钠溶液中比较碳、硫的非金属性强弱
D将钠、镁、铝投入等浓度盐酸中比较Na、Mg、Al的金属性强弱

答案

答案:D

非金属性强弱和氢化物的熔沸点没有关系,和氢化物的稳定性有关。A不正确。B中和氨水反应都生成白色沉淀,不能半径比较金属性强弱,不正确比较非金属性强弱,利用的最高价氧化物对应水化物的酸性强弱,SO2溶于水生成亚硫酸,,C不正确。比较金属性强弱可以利用和酸生成氢气的难易程度进行比较,所以选项D是正确的。答案选D。

单项选择题
阅读理解

No one likes germs.You wash your hands often and avoid sick people.But some of the germiest places are in your own home where you can’t avoid them!

Over 77,500 bacteria per square centimeter can live in your kitchen sink drain.More bacteria live in and around the sink itself.To get rid of them,clean the entire sink area with a disinfectant

Those wet clothes from your washer are not all that clean,especially if they include underwear.Use hot water and bleach to wash underwear as it contains E.colin(大肠秆菌).Put wet laundry in the dryer quickly so the bacteria do not multiply.

The germs you wash off your body stay in the tub-about 15.500 bacteria per square centimeter! Use a disinfectant to clean your tub weekly.And dry the tub with a clean towel so more germs won’t grow on the wet surface.

You’ll find plenty of germs outside your home too.

Lots of germs live on the buttons of your local ATM.According to www.health.corn,Chinese researchers tested 38 ATMs in downtown Taipei.They found that each button hosted an average of 1,200 germs.Use a hand sanitizer after using the ATM and after handling paper money too.

The bottoms of women’s purses house tens of thousands if not millions of bacteria.University of Arizona researchers discovered all kinds of different bacteria on purse bottoms.These included E.coli as well as bacteria that cause eye and skin infections.Women should wipe their purses every few days with a mild soap solution.

All kinds of germs live on shopping cart shopping cart handles.Lots of people touch the handles each day——and who knows where their hands have been! Carry disinfectant wipes and use them on the handles.That will kill nearly a11 germs.

64.How many germy places are mentioned in this passage?

A.two                        B.four                       C.six                         D.eight

65.What does the underlined word disinfectant mean in the second paragraph?

A.a kind of germ

B.a tablecloth

C.a kind of cleaning tool

D.a kind of chemical liquid which can kill germs

66.Which of the following statement is NOT true according to the passage?

A.Some of the germiest places are outside your home.

B.Use a disinfectant to clean your bathtub weekly.

C.Use a hand sanitizer after using an ATM or handling paper money.

D.Thousands of not millions of bacteria live on the bottoms of women’s purses.