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Topic: Some questions. ( Physiological Chem Lab)  (Read 3806 times)

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Offline MysteriousEd

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Some questions. ( Physiological Chem Lab)
« on: October 27, 2013, 10:21:12 AM »
I really don't understand these questions, I know it is not allowed to answer people's question, but I need help on how to answer these questions. I am failing chemistry lab, so I need to do good. That's why I am asking for help.

1) A medical laboratory scientist needs to prepare 500.0 mL of a solution that is 5.0 mM in K+ for diluting serum. What volume, in mL, of a 5.0% (m/v) KCI solution is required to make this solution?

2) How many mL of a 1.0% m/v stock solution are needed to prepare 50.0 mL of a 0.20% solution?

3) How many grams of Na2SO4 are contained per liter of a 0.500 M solution?

4) How many grams of MgCl2 are needed to prepare 750 mL of a 0.50 M solution?

5) A solution is prepared by dissolving 125g of Na3PO4 in enough water to make two liters of solution. Determine the concentration of this solution in units of :  A) % m/v  , B) molarity (i.e., mol/L)  C. osmolarity (i.e., osm/L)

6) What is the molarity of a solution made by dissolving 25 g of NaCl in 750 mL of water?

7) How many grams of NaCl are needed to prepare 3.0 L of a 5.0 % m/v solution?

8) What is the concentration in % m/v of a solution prepared by dissolving 35 g of NaOH in enough water to make 2.5 L of solution?

9) A 15% m/v solution is prepared by diluting 50mL of a stock solution with water up to 125 mL of solution. What is the concentration of the stock solution in % m/v?

10. If a patient has a fasting blood sugar of 76 mg/dL, what is his blood sugar in mmol/L?

11: What is the osmolarity of a 2.2 M solution of MgCl2?

12: What is the molarity of a 0.25 Osm solution of NaCl?

13: What is the concentration in % m/v of a 2.0 M NaOH solution?
« Last Edit: October 27, 2013, 11:08:39 AM by MysteriousEd »

Offline billnotgatez

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Re: Some questions. ( Physiological Chem Lab)
« Reply #1 on: October 27, 2013, 10:26:49 AM »
It appears you are asking us to do your quiz for you
According to forum rules that is a not allowed
please read forum rules

Offline MysteriousEd

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Re: Some questions. ( Physiological Chem Lab)
« Reply #2 on: October 27, 2013, 11:06:22 AM »
It appears you are asking us to do your quiz for you
According to forum rules that is a not allowed
please read forum rules

OK, sorry. It is just that I am failing, but you know, I prefer to fail if I don't understand rather than passing and not understanding.
How about we do some questions and you can give me the formula and I will solve it, hopefully? I will then practice using the formula provided until I get it.  There will be questions like this on the exam, so I wanna make sure I get it.

Offline MysteriousEd

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Re: Some questions. ( Physiological Chem Lab)
« Reply #3 on: October 27, 2013, 11:23:09 AM »
For number 11 , I got 6.6. Is it correct?

For number 7 I got 150g.

Offline Vicktor

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Re: Some questions. ( Physiological Chem Lab)
« Reply #4 on: October 27, 2013, 12:14:18 PM »
OK, sorry. It is just that I am failing, but you know, I prefer to fail if I don't understand rather than passing and not understanding.
How about we do some questions and you can give me the formula and I will solve it, hopefully? I will then practice using the formula provided until I get it.  There will be questions like this on the exam, so I wanna make sure I get it.

I am inclined to think that you were given the equations for these problems somewhere prior to the assigned homework. I would look over the equations, make sure all units are converted to the proper unit of measure and see which equation you can plug your units in to.

Offline MysteriousEd

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Re: Some questions. ( Physiological Chem Lab)
« Reply #5 on: October 27, 2013, 01:16:12 PM »
I know that already, but I don't know how to use those equations. I'll just try my best ..  40 points is a lot and I am sure I will get around 10 points out of 40! No life savers here :( I at least want someone to help me out with just a few problems, like 5-6 questions, short ones.

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