Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: brettphillips on January 12, 2007, 02:09:26 PM
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Hi guys,
First I would like to say how thankful I am to have stumbled on this forum. I am having a problem getting this converted correctly. I am not looking the answer as much as the prcoess by which I would calculate this answer.
Here is the problem....
Convert 4.22 x 10^-9 meters cubed to microliters.
Here is how I attempted to answer this problem:
1) Convert meters cubed to cm3.
4.22 x 10^-9 m3 * (1 x 10^2 / 1 m)^3 = 4.22 x 10^-7 cm3
Since 1 cm^3 = 1 mL, 4.22 x 10^-7 cm3 = 4.22 x 10^-7 mL
2) Convert mL to uL.
4.22 x 10^-7 mL * (1 x 10^3 uL / 1 mL) = 4.22 x 10 ^-4 uL
because 1000 uL in 1 mL
3) Final answer .000422 uL
However, this is not coming up at the correct answer. Where am I goofing up?
Thanks,
Brett :)
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Your step 1:
There is 1000 mL in a liter, you have it as 100.
You are also forgetting about the ^3, the simplest method is to bring it inside and make that 1x106
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ok, I am still lost.
In my step one... the first thing that I did was convert m3 to cm3 because 1 cm3 = 1 mL.
That is why I took the original amount and multiplied by (1x10^2 cm / 1m)^3 since their are 100 cm in 1 M When I do this, I come up with 4.22 x 10^-7 cm3, which would equal the same amount of mL.
In my problem, I never converted to L (or if I did, I dind't know it)... lol
So where is my logic missing?
Thanks for your prompt reply :)
Brett
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**I made a typo, ignore this post brettphillips, or read it and learn the mistakes, but do not spend too long trying to understand this one**
You are thinking in two dimensions.
When you have the cubed you add another dimensions.
1 cm3 = 1 mL
1 L = 1000 mL = 1000 cm3
1m3 = (1000 cm3)3 = 1000L
So 4.22x10-9 m3 = 4.22x10-9 L = 4.22x10-9 (1000 cm3)3 = 4.22x10-3 cm3
And note, when I said bring the ^3 inside earlier to 6, I was mistaken. When I said that I was looking at your 2 inside, not the appropriate 3.
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1 cm3 = 1 mL
1 L = 1000 mL = 1000 cm3
1m3 = (1000 cm3)3 = 1000L
I might be being slow, but I don't follow your maths, surely:
(1000 cm3)3 = 1L3
Not equal to 1m3 or 1000L
I would explain this as follows:
1m = 100 cm
(1m)3 = (100 cm)3
13m3 = 1003cm3
1m3 = 106cm3
ie. 1 cubic metre equals one million mLÂ (or one thousand litres)
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Ok, After re reading I see what you where saying.
I made an obvious typo. My bad, I suck. It was late.
I said:
"1m3 = (1000 cm3)3 = 1000L"
Now since there is obviously 100cm in a meter, that is wrong. I accidentally added an extra 0. Not only do I suck, but the 0 key on my keypad is acting up! ;)
It should be
1m3 = (100 cm)3 = (1003 cm3)= 1000L
Which is the same thing Dan said.
Again I suck, stupid typo!
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...HOLD ON
I was ready to point a thing or two, but it looks like you have spotted them before I even quoted your post ;)
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I was ready to point a thing or two, but it looks like you have spotted them before I even quoted your post ;)
Yeah, even when I was reading myself what I first responded with I was reading what I intended in my head, I was not reading my again screwed up extra zero or that I had already put the cube inside (copy and paste for the lose!..I should hit preview more with all the numerous superscript blocks of code). I am a tard I tell ya!
I should not post before I get my morning shower! :)
*edit*
And in my defense, because nobody likes having their mistakes immortalized! At the end where I calculate it with his numbers, I still get the correct cm3 :), I just kept copying and pasting the mistake(s) I made.