问题 阅读理解
用方框中所给单词的适当形式填空,使短文通顺、正确、连贯(每个单词限用一次)。
something,   not,   tree,   simply,   spend,   you,   why, 
 that,   they,   if,   little,   go,   in,   on,   protect
The Earth needs a helping hand
     The Earth is getting warmer because of the activities of people. We cut down and burn 1______ and
send gases into the air with our cars and factories. Can we do anything about it? Sure. We may 2______
be leaders or scientists but we can play our part in 3______ the planet. Here are two ideas.
Bike, don't ride to school
     Do you 4______ to school by bus or by bike? If you bike, you are doing 5______ for the Earth. Buses,
cars, trains and planes produce a lot of carbon dioxide (二氧化碳). If you live near to your school, 6______
not bike there on warm spring mornings? Or, you can 7______ walk to school to save energy. 
 Wash the green way
     Do you help your mom and dad wash clothes? Then wash them 8______ an energy-saving way. A recent
study by Cambridge University found 9______ 60 percent of the energy used on a piece of clothing is 
10______ in washing and drying it. Over ita lifetime, a T-ahirt can send up to 4 kilograms of carbon dioxide
into the air.  
     11______ you wash your own clothes, wash them in cold or warm water to save energy, but not hot water.
Wash your clothes when 12______ fill up the machine. Use the most energy-saving machine you can find.
Some new ones use as 13______ as one-fourth of the energy of older machines. When they're clean, dry 
14______ clothes the natural way, by hanging them 15______ a line rather than putting them in a dryer. In all,
you can cut the carbon dioxide used in washing by 90 percent.
答案

1. trees   2. not   3. protecting  4. go  5. something

6. why  7. simply  8. in   9. that  10. spent  

11. If   12. they   13. little   14. your  15. on

问答题

(1)测定Na2O和Na的混合物中金属钠的质量分数可用下图所示的几套仪器组合:

①用接口字母标出各仪器连接的顺序______量筒在实验中的作用是______

②有一块表面氧化成Na2O的金属钠,其质量为2.0g,实验后在量筒中收集到0.224L水,求样品中金属钠的质量分数是______.(假设在标准状况下测定)

(2)(10分)HNO2是一种弱酸,且不稳定,易分解生成NO和NO2;它能被常见的强氧化剂氧化;在酸性溶液中它也是一种氧化剂,如能把Fe2+氧化成Fe3+.AgNO2是一种难溶于水、易溶于酸的化合物.试回答下列问题:

①人体正常的血红蛋白含有Fe2+.若误食亚硝酸盐(如NaNO2),则导致血红蛋白中的Fe2+转化为Fe3+而中毒,服用维生素C可解毒.下列叙述不正确的是______(填序号).

A.亚硝酸盐被还原B.维生素C具有还原性

C.维生素C将Fe3+还原为Fe2+D.在上述变化中亚硝酸盐是还原剂

②下列方法中,不能用来区分NaNO2和NaCl两种溶液的是______(填序号).

A.测定这两种溶液的pH

B.分别在两种溶液中滴加甲基橙

C.在酸性条件下加入KI-淀粉溶液来区别

D.用AgNO3和HNO3两种试剂来区别

③某同学把新制的氯水加到NaNO2溶液中,观察到氯水褪色,同时生成NaNO3和HCl,请写出反应的离子方程式:______.

④Fe与过量稀硫酸反应可以制取FeSO4.若用反应所得的酸性溶液,将Fe2+转化为Fe3+,要求产物纯净,可选用的最佳试剂是______(填序号).

a.Cl2 b.Fe c.H2O2 d.HNO3

⑤配平下列方程式:□Fe(NO33+□KOH□Cl2→□K2FeO4+□KNO3+□KCl+□H2O.

单项选择题