A.6
B.5
C.4
D.3
5 3 -1 2 O-|||-1 7 2 5 2-|||-例2 计算行列式 D= .0 .-2 3 1 0-|||-0 .-4 .-1 4 0-|||-O 2
已知K2Cr2O7在水溶液中有下列平衡:Cr2O7 2- + H2O = 2 HCrO4-其中,Cr2O7 2- 与HCrO4- 都对可见光有吸收, 且ε450
[单选题]0,2,2,5,4,7,( )。A.6B.5C.4D.3
2 -5 1 2-|||--3 7 -1 4-|||-计算 D=-|||-5 -9 2 7-|||-4 -6 1 2
[单选题]:O,1,1,2,4,7,13,( )A.22B.23C.24D.30
已知1 2 -2 4-|||-2 2 2 2-|||-1 4 -3 5-|||--1 4 2 7,1 2 -2 4-|||-2 2 2 2-|||-1 4 -3
[问答题] 用硼砂(Na2B4O7?10H2O)标定盐酸溶液时,其反应式是:Na2B4O7+2HCl+5H2O=4H3BO3+2NaCl称取0.4767g纯硼砂标定某盐酸溶液,共用了25.00ml,该盐酸,计算此盐酸的浓度?(Na2B4O7?10H2O的摩尔质量为381.4g/mol)
[主观题]a=[1,2,4,2,4,5,7,10,5,5,7,8,9,0,3],编程用sort进行排序,然后从最后一个元素开始判断?
3.向K2 Cr2O7溶液中滴加BaCl2溶液,生成的沉淀为 ()-|||-(A)BaCr2O7; (B)Ba(HCr2O 7)2;-|||-(C)BaCrO4
5.高锰酸钾在酸性条件下可氧化H2O2:(O)_(4)+5(H)_(2)(O)_(2)+6(H)^+=8(H)_(2)O+5(O)_(2)uparrow +2(