计算稀释溶液的浓度的公式：
V1×M1 = V2×M2
V =V2 -V1
V1 = 稀释前体积n
V2 = 稀释后体积
M1 = 前稀释浓度
M2 =稀释后浓度
V = 合计溶剂稀释
具体的溶液的变化过程如下：
(1)取5ml的溶液加水稀释到25ml
1000μg/ml * 5ml / 25ml = 200μg/ml
(2)再由(1)取20ml稀释到25ml
200μg/ml * 20ml / 25ml = 160μg/ml
(3)再由(2 )取20ml稀释到25ml
160μg/ml * 20ml / 25ml = 128μg/ml
(4)再由(3 )取12.5ml稀释到25ml
128μg/ml * 12.5ml / 25ml = 64μg/ml
(5) 再由(4)取2ml稀释到10ml
64μg/ml * 2ml / 10ml = 12.8μg/ml
(6) 由(5)取5ml的溶液加水稀释到25ml
12.8μg/ml * 5ml / 25ml = 2.56μg/ml
(7) 由(6)取20ml稀释到25ml
2.56μg/ml * 20ml / 25ml = 2.048μg/ml
(8) 由(7 )取20ml稀释到25ml
2.048μg/ml * 20ml / 25ml = 1.6384μg/ml
(9) 由(8 )取12.5ml稀释到25ml
1.6384μg/ml * 12.5ml / 25ml = 0.8192μg/ml
扩展资料：
关于溶液摩尔浓度的计算：
1、已知溶质的质量m，和溶液的体积V，假设溶质的摩尔质量为M，溶质的摩尔浓度为c=m/MV
2、已知溶质的物质的量n，和溶液的体积V， 溶质的摩尔浓度为c=n/V
3、已知溶质的质量分数w，和溶液的密度p，溶质的摩尔质量为M 溶质的摩尔浓度为c=1000pw/M
4、已知溶液的质量m，和溶液的体积V，溶液的密度w 溶质的摩尔浓度为c=1000mw/MV
参考资料来源：百度百科-稀释定律