问题 问答题

实验室里用浓盐酸和二氧化锰共热制Cl2:MnO2+4HCl(浓) 

  △  
.
 
 MnCl2+Cl2↑+2H2O

(1)用“线桥法”表示出电子转移情况:MnO2+4HCl(浓) 

  △  
.
 
 MnCl2+Cl2↑+2H2O

(2)该反应中,氧化剂是______,还原剂是______.

(3)当转移电子的数目为6.02×1023个时生成的氯气在标准状况下的体积为______L.

答案

(1)化合价升高元素是氯元素,失电子,化合价降低元素是锰元素,得到电子,化合价升高数=化合价降低数=转移电子数=2,电子转移情况如下:

,故答案为:

(2)化合价降低元素所在的反应物MnO2是氧化剂,化合价升高元素所在的反应物HCl是还原剂,故答案为:MnO2;HCl;

(3)反应MnO2+4HCl(浓) 

  △  
.
 
 MnCl2+Cl2↑+2H2O转移电子2mol时,生成的氯气物质的量为1mol,当转移电子的数目为6.02×1023个即1mol时,生成的氯气物质的量为0.5mol,体积为:0.5mol×22.4L/mol=11.2L,故答案为:11.2.

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阅读理解

阅读理解。

     Hawaii's Big Island

     Nickname: Hawaii's Island of Adventure 

     Size: 4,028 square miles

     Population: 148,677.The most heavily populated areas are Hilo on the east side and Kailua-Kona on the

west.

     Temperature: Averages between 71°F and 77°F year round (expect the mercury (水银柱) to drop at

higher heights)

      Highest Peak: Mauna kea,13,796 feet

     Agriculture: Hawaii's agricultural products are mainly grown and processed On the Big Island, including

coffee, macadamia nuts and papaya.

     Lodging: 9,655 rooms total;Nightly rates range from$35 to$5,000.

     Airports: Hilo International Airport on the east side and Kona International Airport on the west side.

     Rental Cars: All of the nationally known rental car companies have locations at Hilo International and

Kona International Airports as well as numerous resorts. In addition, Hilo, Kona and the major resort areas

are serviced by taxis.

     Resources: Call(800)648-2441 to order a video poster, brochures and maps from the Big Island Visitors

Bureau. See WWW.Bigisland,org for updated information.

     Shopping: The large shopping centers are in Hilo, Kona, Waimea and the Kohala Coast.

1. ______ are mostly interested in reading the passage.

A. Students

B. Tourists

C. Businessmen

D. Officials

2. The average population per square mile on the island is about _____.

A. 28

B. 32

C. 37

D. 44

3. What does the underlined part "expect the mercury (水银柱) to drop at higher heights" mean?

A. Things are easy to lose weight at higher places.

B. Dropping things from higher places is expected.

C. Temperature is expected to be lower at higher places.

D. Temperature is expected to be higher at higher places.

4. Which is NOT mentioned as a traffic means to get around the Big Island?

A. By train.

B. By air.

C. By rental car.

D. By taxi.

5. Which of the following statements is true according to the passage?

A. You can see www.bigisland.org for updated information.

B. You can call (800) 648-2441 to order some food.

C. You can find some courts to play tennis on the island.

D. You may pay a high price for spending one night on the island.