题目

K2Cr2O7是橙红色晶体，K2CrO4是黄色晶体，若将K2Cr2O7配成一定浓度的溶液，可以发生的离子反应方程式为：Cr2O2-7+H2O2CrO2-4+2H+，当达到平衡时，溶液的颜色在橙色和黄色之间，试回答：  (1)向盛有2mL的上述K2Cr2O7溶液的试管中滴入10滴2mol·L-1的NaOH溶液，则试管中的溶液呈             色.原因是                    .  (2)向(1)所得的溶液中滴入5滴2mol·L-1的硫酸，试管中溶液呈            色，理由是           . 阅读理解     BEIJING - After a night of wining and dining with 50 of China's richest people, Warren Buffet andBill Gates told the journalists on Thursday that the biggest difference between eating with Chinesetycoons (企业界大亨) and Western ones was the food.     "I was amazed last night, really, at how similar the questions and discussions and all that were to thosein the dinners we had in the U.S.," said Mr. Buffett.     Mr. Buffett and Mr. Gates, two of the best known Westerners here, announced in September, 2010 that they planned to invite 50 wealthy Chinese tycoons to dinner in Beijing to encourage philanthropy (慈善事业) among China's new rich.     On Thursday, the two men pronounced the dinner a great success, saying that two-thirds of those invited had shown up, and that more than half of them had offered their own ideas on how Chinese philanthropy should work.     The guest list wasn't made public, but the Chinese news media reported that it included Jet Li, the movie star; Niu Gensheng, the founder of a Chinese dairy business; and Pan Shiyi and Zhang Xin, who control the SOHO China real estate (房地产) empire.     As with four earlier dinners held in the United States, Mr. Buffett and Mr. Gates said, no one at the Beijing event was asked to donate money or to promise to engage in charity. "Bill and I won't be calling anybody. What happens in China will depend on what the Chinese people feel about a project of this sort," said Mr. Buffett.     China is widely reported to be second only to the United States in the number of dollar billionaires. Mr. Gates and Mr. Buffett said the nation was unique because its wealthy class had arisen almost whollyin the past 30 years, so the philanthropic practices established among European and American dynasties are new here, and open to change.     The two said the dinner wasn't a long planned matter, but an offshoot (衍生事物) of a trip that Mr.Buffett had already scheduled to Guangdong and Hunan Provinces, where BYD Company, a maker of clean-energy automobiles, has factories. Mr. Buffett's company, Berkshire Hathaway, holds a 10% stake (股金) in the company.     But Mr. Gates suggested that their philanthropic trip wasn't yet over. "We may do an event in India,"he said.1. What is the text mainly about?   A. A brief analysis of future philanthropy.   B. The development of Chinese philanthropy.   C. An introduction on Mr. Buffett and Mr. Gates' trip in China.   D. A charity dinner held in Beijing by Mr. Buffett and Mr. Gates.2. According to the first two paragraphs, Mr. Buffett really wanted to say that _____.   A. the dinner was quite a success   B. the food in the dinner was very delicious   C. Chinese tycoons are similar to Western ones   D. it was pleasing to discuss with Chinese tycoons3. We can learn from the text that __________.   A. China has the largest number of dollar billionaires in Asia   B. many people have promised to donate money at dinner   C. Beijing will be the last stop of their philanthropic trip   D. the Chinese news media published the complete guest list of the dinner