视频欣赏:Rainbow Connection,自带BGM的彩虹反应
给创意实验配上音乐~...
酸碱指示剂变色反应大家也看过不少了,不过今天的这个可不一般,这是一个带配乐的彩虹反应,通过烧杯中的反应完美呼应了歌曲Rainbow Connection的主题~
在这里,我们可以看到“彩虹”的种种变化,一开始的变色没有成功,中间又会消失,但是我们终将找到彩虹。(不过最后彩虹还是没了_(:з」∠)_)
完整版视频,配合音乐欣赏感觉更佳:
这个颇有创意的音乐化学秀其实也是酸碱指示剂变色的体现,只不过在这里综合使用了三种指示剂调出彩虹的色彩。这三种指示剂在酸性条件下都是无色的,而碱性条件下可以变成不同的颜色:酚酞变红,对硝基苯酚变黄,百里酚酞变蓝。通过它们的调和还可以得到橙色、绿色和紫色。
一开始,放在杯子里的是酸性环境的指示剂溶液,它们都是无色的。大瓶子里装的是氢氧化钠溶液。一开始,氢氧化钠溶液加的不多,不足以中和掉杯子里的酸,所以这时候彩虹并不会显现。接下来,只要加了足够多的碱性溶液,指示剂就可以变色,显示出了美丽的彩虹。
再接下来,滴管加入的几滴液体是浓硫酸和甘油的混合溶液。这种粘稠的酸溶液刚加进去时不会很快扩散开,所以不会立刻变色,而搅拌之后酸又会消耗掉了碱,让指示剂褪色,彩虹又消失不见了。而只要再坚持不懈地往杯子里加入更多碱,彩虹就又回来啦。
最后,彩虹的颜色看起来两两“中和”归于无色,而真正“中和”它们的其实还是大烧杯里预先加入的酸,溶液中的碱再次被消耗,最终指示剂们又回到了无色状态。这段彩虹的故事是不是感觉很美呢~
戳阅读原文,可以看到关于这个实验的详细介绍。
下面附上Rainbow Connection的歌词:
Why are there so many songs about rainbows ?
And what's on the other side ?
Rainbows are visions but only illusions
And rainbows have nothing to hide
So we've been told
And some choose to believe it
I know they're wrong, wait and see
Someday we'll find it
The rainbow connection
The lovers, the dreamers and me
Who says that every wish would be heard and answered
When wished on a morning star
Somebody thought of that
And someone believed it
Look what it's done so far
What's so amazing that keeps us star-gazing?
And what do you think we might see
Someday we'll find it
The rainbow connection
The lovers, the dreamers and me
All of us under its spell
We know that it's probably magic
Have you been half asleep
And have you heard voices
I've heard them calling my name
Is this the sweet sound that calls the young sailors
The voice might be one and the same
I've heard it too many times to ignore it
It's something that I'm supposed to be
Someday we'll find it
The rainbow connection
The lovers, the dreamers and me
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