问题 选择题

设NA表示阿伏加德罗常数值,下列叙述正确的是(  )

A.NA个氧气分子和NA个氢气分子的质量比为16:1

B.标准状况下,22.4LH2O含有的分子数为NA

C.11.2L 氯气中含有的原子数为NA

D.2L 1mol/L Na2SO4溶液中Na+离子数为2NA

答案

A.分子数相同的氧气和氢气的物质的量相等,氧气的摩尔质量是32g/mol,氢气的摩尔质量是2g/mol,结合m=nM知,二者质量质量比为16:1,故A正确;

B.标况下,水是液体,气体摩尔体积对其不适用,所以22.4LH2O含有的分子数不是NA,故B错误;

C.温度和压强未知,所以气体摩尔体积未知,导致无法计算氯气的物质的量,故C错误;

D.2L1mol/L Na2SO4溶液中Na+离子数为4NA个,故D错误;

故选A.

阅读理解

阅读理解。

     In 1608 an Englishman named Thomas Coryate visited Italy. He liked the country and wrote down

every interesting thing he found. But there was one thing which he found the most interesting. In his diary

Thomas wrote, "When the Italians eat meat, they use small forks. They do not eat with their hands,

because people do not always have clean hands."

     Before leaving for England, Thomas Coryate bought a few forks.

     At home Thomas had a dinner party to show the invention to his friends. When the steak (牛排) was

brought out, he took out a fork and began to eat as they did in Italy.

     Everybody looked at him in surprise. When he told his friends what the fork was, they all wanted to

take a good look at the strange thing. All his friends said that the Italians were very strange people

because the fork was not easy to use at all.

     Thomas Coryate tried to prove (证明) that his friends were wrong. He said it was not nice to eat

meat with one's fingers because they were not always clean.

     Everybody got angry at that. Did Mr. Coryate think that people in England always had dirty hands?

And weren't the ten fingers we had enough for us?

     Thomas Coryate wanted to show that it was very easy to use the fork. But the first piece of meat he

took with the fork fell to the floor. His friends began to laugh and he had to take the fork away.

     People in England began to use forks only fifty years later.

1. Why did Thomas Coryate bring forks to England?

A. He wanted to surprise his friends.

B. He believed that it was not nice to eat meat with fingers.

C. Forks were beautiful.

D. He wanted to make business selling forks.

2. Why did everybody look at Thomas when he began to eat like the Italians?

A. They believed that was bad manners.

B. Nobody ate meat with hands in England.

C. Everybody thought it was an amazing invention.

D. Nobody had seen a fork before.

3. People were _____ when Thomas said that they shouldn't eat meat with their fingers.

A. unhappy

B. sorry

C. sad

D. worried

4. The first piece of meat fell to the floor when Thomas took it with the fork because _____.

A. the fork was very difficult to use

B. the fork was bad

C. Thomas could not use it quite well

D. the steak was too hard

单项选择题