chbare Posted October 21, 2009 Posted October 21, 2009 (edited) Thought I would do something challenging, possibly fun, and a reminder of just how complex something we take for granted every day can be. Anybody with a degree in chemistry, biology, engineering, or physics need not post. Okay, here goes. Normal saline, we all give it, we all talk about it, do we really know it on a fundamental level? So, take a look at a liter of the ever present 0.9 % normal saline. What does it say on the bag? Do you see something about milliequivalents? What does this mean and can we do any meaningful calculations to better understand this common medication? Take care, cbare. Edited October 21, 2009 by chbare
Just Plain Ruff Posted October 21, 2009 Posted October 21, 2009 Damn you and your Chemistry questions - Damn you. Minus 1 for making me think today
dad7892 Posted October 21, 2009 Posted October 21, 2009 Thought I would do something challenging, possibly fun, and a reminder of just how complex something we take for granted every day can be. Anybody with a degree in chemistry, biology, engineering, or physics need not post. Okay, here goes. Normal saline, we all give it, we all talk about it, do we really know it on a fundamental level? So, take a look at a liter of the ever present 0.9 % normal saline. What does it say on the bag? Do you see something about milliequivalents? What does this mean and can we do any meaningful calculations to better understand this common medication? Take care, cbare. I spent a few years as an EMT-I/D. If I remember correctly, the milliequivalents are the amount of sodium in the Liter of water. It can be used as fluid replacement since the sodium level is the same as in the human body. It can also be used as small sodium replacement therapy, however, a more concentrated solution would be better. I have also used it for flushing out eyes and rinsing off wounds. Am I answering your question, or am I on the wrong track? Dad7892
chbare Posted October 21, 2009 Author Posted October 21, 2009 Not exactly, but many people think this. A mEq is derived from equivalent. 1000 mEq = 1 equivalent. The definition of an equivalent is moles times charge. So, let's start at moles. What is a mole & how does it relate to the question at hand? Take care, chbare.
scubanurse Posted October 21, 2009 Posted October 21, 2009 a mole is a unit of measurement in chemistry...basically one mole is equal to the atomic mass of a molecule So Oxygen has an atomic mass of 15.9999g so one mol of oxygen would be 15.9999g Also seen as Avagado's Number 6.02 x 10^23 I think that's right?
chbare Posted October 21, 2009 Author Posted October 21, 2009 Good: specifically, a mole is 6.02 * 10^23 atoms of an element or molecules of a substance. Therefore one mole of O2 would have a weight of ~ 32 grams. Ok, so what about moles of saline? Take care, chbare.
scubanurse Posted October 21, 2009 Posted October 21, 2009 I'll have to think on that as I sit in my chem lecture in a few minutes and get back to you
spenac Posted October 21, 2009 Posted October 21, 2009 Wrong a mole is a creature that lives underground or a dark spot on the skin or a spy or a ................... Actually thanks for this though it is going to make me have to do research again.
chbare Posted October 21, 2009 Author Posted October 21, 2009 No problem guys, we will talk about individual concepts, then hopefully put it together into a cohesive format. So Far we know: 1000 mEq = 1 Eq, 1 Eq = Mole/charge, Mole = Avagadro's number or 6.02 * 10 ^23 atoms/molecules Further explanation: 6.02 * 10^23 is what we call scientific notation. When numbers are too small or large for conventional context or understanding, we put them into this format. We essentially make a smaller decimal number and use a factor of 10 to describe how many times we multiply that decimal or whole number by ten to reach the actual number. For example: 1,000 would equal 1.0 * 10 ^3 ( If we multiply by ten, three times, or move the decimal to the right three spaces, we have the actual number) Likewise: 0.001 would equal 1.0 * 10 ^ -3 ( Very small numbers less than one use a negative value, or we move the decimal to the left to obtain the actual number. Therefore, you can see the 6.02 * 10^23 is so incredibly large that understanding it in a conventional context and writing the entire number out is unreasonable and inherently difficult, if not impossible for most people. The next thing to describe is the concept of charge? Take care, chbare. 1
Just Plain Ruff Posted October 21, 2009 Posted October 21, 2009 No problem guys, we will talk about individual concepts, then hopefully put it together into a cohesive format. So Far we know: 1000 mEq = 1 Eq, 1 Eq = Mole/charge, Mole = Avagadro's number or 6.02 * 10 ^23 atoms/molecules Further explanation: 6.02 * 10^23 is what we call scientific notation. When numbers are too small or large for conventional context or understanding, we put them into this format. We essentially make a smaller decimal number and use a factor of 10 to describe how many times we multiply that decimal or whole number by ten to reach the actual number. For example: 1,000 would equal 1.0 * 10 ^3 ( If we multiply by ten, three times, or move the decimal to the right three spaces, we have the actual number) Likewise: 0.001 would equal 1.0 * 10 ^ -3 ( Very small numbers less than one use a negative value, or we move the decimal to the left to obtain the actual number. Therefore, you can see the 6.02 * 10^23 is so incredibly large that understanding it in a conventional context and writing the entire number out is unreasonable and inherently difficult, if not impossible for most people. The next thing to describe is the concept of charge? Take care, chbare. See you did learn something in that high mighty fallutin chemistry class you have taken recently.
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