下列物质按1﹕1反应的离子方程式正确的是
A．氯气和水 Cl2 + H2O = Cl- + ClO- + 2H+
B．硫代硫酸钠与硫酸 S2O32- + 2H+ =" S↓" + SO2↑ + H2O
C．氯化铜和硫氢化钠 Cu2+ + S2- + 2H2O = Cu(OH)2↓ + H2S↑
D．(NH4)2 Fe (SO4)2和氢氧化钡 2NH4+ + 2OH- + Ba2+ + SO42- = NH3?H2O + BaSO4↓
答案：B
正确答案：B
A、是可逆反应；B、正确；C、Cu2＋＋HS―=CuS↓＋H＋ D、Fe2＋ ＋2OH- + Ba2+ + SO42- = Fe(OH)2↓ + BaSO4↓
根据句子意思，从方框中选择恰当的词或短语填空。
2. Zhai Zhigang became the first Chinese man to ________ on Saturday, September 27, 2008. 3. The Chinese word "Shanzhai" is now used to describe products that have names ________ famous brands or people who imitate celebrities. 4. A witness reported that he was ________ and had blood on his shirt. 5. She had put most of her effort into ballet training before ________ the film industry. 6. I’m afraid she doesn’t want to write to me ________. 7. It’s important for us junior students to spent some time on our ________. |