这个怎么也算不出70%啊
君已陌路 发表于 4/11/2020 4:45:17 PM [url=https://forums.huaren.us/showtopic.aspx?topicid=2528416&postid=83566865#83566865][img][/img][/url]

加多少毫升水？

谁知道加多少毫升水吗

946x0.91=0.7 X
X=1229.8
1229.8-946=283.8毫升
加283.8毫升水？

Measure out one cup of 91 per cent rubbing alcohol, and pour it into the plastic container. Add one-third of a cup of water and stir to mix the solution. The solution is now 70 per cent rubbing alcohol. Repeat this procedure as often as needed to obtain the desired amount of 70 per cent rubbing alcohol.

有人已经算过了，32OZ的91%的酒精加6.7的水就是70%浓度的酒精了。

smile1234 发表于 4/13/2020 1:36:48 PM [url=https://forums.huaren.us/showtopic.aspx?topicid=2528416&postid=83591753#83591753][img][/img][/url]

加9.6oz水

32*0.91/0.7-32