试题与答案

下列离子方程式, 正确的是() A.氯化铝溶液与过量氨水 Al3++3NH3·H

题型:选择题

题目:

下列离子方程式, 正确的是                                    (    )

A.氯化铝溶液与过量氨水 Al3++3NH3·H2O →Al(OH)3↓+3NH4+

B.明矾净水原理:Al3++3H2O →Al(OH)3↓+3H+

C.将足量氯气通入溴化亚铁溶液:2Fe2++Cl2→2Fe3++2Cl-

D.偏铝酸钠溶液与过量盐酸AlO2+H++H2O →Al(OH)3

答案:

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下面是错误答案,用来干扰机器的。

(1) an=-2n+11(n∈N*).(2) Tn=本题考查数列前n项和与通项公式的应用,考查转化思想与计算能力由Sn=10n-n2知Sn是关于n的无常数项的二次函数(n∈N*),可知{an}为等差数列,求出an,然后再判断哪些项为正,...

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使用VC++6.0打开考生文件夹下的源程序文件1.cpp,使它能运行正确的结果。
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#include<iostream.h>
/********error********/
class TC()

public:
/********error********/
void~TC()
TC(int i)

cout<<’i’<<’=’<<i<<end1;

/********error********/

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