问题 选择题

用NA表示阿伏加德罗常数,下列说法中正确的是:(  )

①18gD2O含有的电子数为10NA   ②同温、同压下,相同体积的氟气和氩气所含的原子数相等   ③标准状况下,11.2L以任意比例混合的氮气和氧气所含的原子数为NA   ④在标准状况下,22.4LSO3的物质的量为1mol   ⑤4℃时5.4mL的水所含的原子总数为0.9NA    ⑥0.1molOH-含NA个电子 ⑦1molNa2O2与水完全反应时转移电子数为2NA

A.③⑤⑥⑦

B.③⑤⑥

C.①②④⑦

D.③④⑤⑥

答案

①每个D2O分子中含有10个电子,但18gD2O的物质的量小于1mol,所以18gD2O含有的电子数小于10NA,故错.

②同温、同压下,相同体积的氟气和氩气的物质的量相等,但氟气是双原子分子,氩气是单原子分子,所以所含的原子数不等,故错.

③标准状况下,11.2L以任意比例混合的氮气和氧气的物质的量是0.5mol,氮气和氧气都是双原子分子,所以标准状况下,11.2L以任意比例混合的氮气和氧气所含的原子数为NA,故正确.

 ④标准状况下,SO3是固体,气体摩尔体积不适用于该物质,故错.

⑤4℃时,水的密度是1g/mL,所以5.4mL的水的质量是5.4g,物质的量是0.3mol,所含的原子总数为0.9NA,故正确.

 ⑥一个OH-离子中含有10个电子,所以0.1mol OH-含NA个电子,故正确. 

 ⑦2mol过氧化钠与水反应转移电子数为2NA,所以1molNa2O2与水完全反应时转移电子数为NA,故错.

故选:B

阅读理解

BEIJIG—The two-day visit to Washington has been heavy for British Prime Minister Gordon Brown as he attempts to improve ties with Washington and promote his international image ahead of the upcoming G-20 economic summit in London.

Special Relationship

Brown had been praising the “ special relationship” between Britain and the United States before he traveled to Washington. “There is no international partnership in recent history that has served the world better than the special relationship between Britain and the United States,” Brown said in an article in The Sunday Times of London. Such enthusiasm was quickly responded by Barak Obama, the new leader of the world’s largest economy. “The special relationship between the United States and Great Britain is one that is not just important to me, it is important to the American people,” told reporters after meeting with Brown.

Brown was the first European leader to meet Obama at the White House, and this might help the British leader make his image smooth among countrymen in a turbulent(动荡)time and put him in a better position to appear side by side with Obama at the April G-20 summit that will consider the international economic crisis.

Global New Deal

The talks between Brown and Obama were expected to focus mainly on measures to jump-start international economic growth in the most serious downturn in decades. Brown will first promote his “goal new deal” with Obama before taking the G-20 talks. The prime minister, who is chairing the G-20 gathering, has said he would push for deep adjustable changes and joint efforts from all of the world’s major economies, developed and developing, to correct financial rules and inspire the global economy.

However, as pointed out by many analysts, there is the potential for bitterness between Britain and the United States. That’s because no small number of Britons believe themselves to be victims of a crisis which they say was set off by the United States. Meanwhile, analysts say it was unrealistic to expect another honeymoon for British-US ties as Obama seems to have attached more importance to the Pacific region than to Europe.

1 Brown paid the two-day visit to Washington in order to _______.

A. improve the ties with the US and his image

B. make Obama’s international image better

C. congratulate Obama on coming into power

D. prepare for the coming G-20 economic summit

2. The April G-20 summit will mainly focus on how ________.

A. to solve the international energy crisis

B. to solve the international economic crisis

C. to relax current international tension

D. to achieve the double-win goal lately

3. According to many analysts, there is the potential for bitterness between the UK and the US because___________.

A. Obama is less friendly to Brown than Brown to Obama

B. Obama hasn’t visited the UK yet as a new president

C. Obama seems to have attached more importance to Europe than to the Pacific region

D. many Britons believe themselves to be the victims of a crisis caused by the US

4. The underlined part in the last paragraph suggests that___________.

A. Britons expect too much from Obama

B. Britain and USA used to have close relationship

C. the relationship between the two countries will break up

D. Obama and the first lady will not spend their honeymoon in Britain

单项选择题