问题
选择题
现将100g 20%的稀硫酸加水稀释为10%的稀硫酸，需加水的质量为（ ）
A．100g
B．200g
C．300g
D．400g
答案
设需要加水为x，
100×20%=（100+x）×10%
X=100g
故选A．
搜题请搜索小程序“爱下问搜题”
现将100g 20%的稀硫酸加水稀释为10%的稀硫酸，需加水的质量为（ ）
A．100g
B．200g
C．300g
D．400g
设需要加水为x，
100×20%=（100+x）×10%
X=100g
故选A．
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