Re: ??? mls: solve difficult problem

[Guest guest]

Jeanetta, Is it?

FV    x  %    =  gm or ml?

1000 x 0.25 = 250ml

From: krshy29 <krshy29@...>

Subject: ??? mls: solve difficult problem

Date: Monday, April 6, 2009, 11:43 PM

A physician orders a liter of half strengh Dakin's Solution. On hand

in the pharmacy is full strength Dakin's Solution (0.5% sodium hypochlorite) .

How many mls of the stock solution are needed?

 

[Guest guest]

Dear All,

I hope that this will be seen or posted in the correct format.

For this problem I used logic + an alligation method:

If full strength is 0.5% then half strength must be 0.25%

(that was the " logic " )

Do a simple alligation for this problem

0.5% ----------0.25/0.5 x 1000 ml = 500 ml of 0.5% Dakin's Sol

-------0.25%----------

0% ----------- 0.25/0.5 x 1000 ml = 500 ml of Water(water)

Makes 1000 ml of 0.25% Dakins Solution

or

1000 ml of 'half-strength' Dakins Solution

Hope this helps Let me know what your book says.

Jeanetta Mastron CPhT BS

Founder/Owner

Method and set up is copyrighted by Jeanetta Mastron

>

> From: krshy29 <krshy29@...>

> Subject: ??? mls: solve difficult problem

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> Date: Monday, April 6, 2009, 11:43 PM

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> A physician orders a liter of half strengh Dakin's Solution. On

hand in the pharmacy is full strength Dakin's Solution (0.5% sodium

hypochlorite) . How many mls of the stock solution are needed?

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[Guest guest]

My answer is 500ml

1000ml x 0.25 = X x 0.5

250ml = 0.5X

x= 250/0.5

x=500ml of 0.5% sodium hypochlorite soln

Please confirm if this is the right answer and solution.Thanks

________________________________

From: krshy29 <krshy29@...>

Sent: Tuesday, April 7, 2009 12:43:19 PM

Subject: ??? mls: solve difficult problem

A physician orders a liter of half strengh Dakin's Solution. On hand in the

pharmacy is full strength Dakin's Solution (0.5% sodium hypochlorite) . How many

mls of the stock solution are needed?

[Guest guest]

I'm sorry that my brain got the answer too fast to be able to break it down for

you to understand, but I will say that that answer is not correct. 

From: krshy29 <krshy29 (DOT) com>

Subject: [JeanettasPTCBStudy Group] ??? mls: solve difficult problem

JeanettasPTCBStudyG roup@groups .com

Date: Monday, April 6, 2009, 11:43 PM

A physician orders a liter of half strengh Dakin's Solution. On hand in the

pharmacy is full strength Dakin's Solution (0.5% sodium hypochlorite) . How many

mls of the stock solution are needed?

 

[Guest guest]

thank you Jeanette, as i got the same answer but i used more logic than you

did.  i saw that it was 1/2 strength so i knew to dilute it 1 to 1 so 500ml of

the 0.5% and 500ml of water would be 1 liter of 0.25% (1/2 strength)

Dear All,

I hope that this will be seen or posted in the correct format.

For this problem I used logic + an alligation method:

If full strength is 0.5% then half strength must be 0.25%

(that was the " logic " )

Do a simple alligation for this problem

0.5% ----------0. 25/0.5 x 1000 ml = 500 ml of 0.5% Dakin's Sol

-------0.25% --------- -

0% ----------- 0.25/0.5 x 1000 ml = 500 ml of Water(water)

Makes 1000 ml of 0.25% Dakins Solution

or

1000 ml of 'half-strength' Dakins Solution

Hope this helps Let me know what your book says.

Jeanetta Mastron CPhT BS

Founder/Owner

Method and set up is copyrighted by Jeanetta Mastron

>

> From: krshy29 <krshy29@... >

> Subject: [JeanettasPTCBStudy Group] ??? mls: solve difficult problem

> JeanettasPTCBStudyG roup@groups .com

> Date: Monday, April 6, 2009, 11:43 PM

>

>

>

>

>

>

>

>

>

>

>

>

> A physician orders a liter of half strengh Dakin's Solution. On

hand in the pharmacy is full strength Dakin's Solution (0.5% sodium

hypochlorite) . How many mls of the stock solution are needed?

>

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[Guest guest]

Yes this method is correct and used most often for TPN calculations of base

solutions that differ from what you have on hand.

Jeanetta Mastron CPhT BS

Pharm Tech Educator

Founder/Owner

>

> My answer is 500ml

>

> 1000ml x 0.25 = X x 0.5

> 250ml = 0.5X

> x= 250/0.5

> x=500ml of 0.5% sodium hypochlorite soln

>

> Please confirm if this is the right answer and solution.Thanks

>

>

>

>

>

> ________________________________

> From: krshy29 <krshy29@...>

>

> Sent: Tuesday, April 7, 2009 12:43:19 PM

> Subject: ??? mls: solve difficult problem

>

>

> A physician orders a liter of half strengh Dakin's Solution. On hand in the

pharmacy is full strength Dakin's Solution (0.5% sodium hypochlorite) . How many

mls of the stock solution are needed?

>

>

>

>

>

>

>

>

[Guest guest]

Good job Karin! This 'logic' comes with a good math aptitude AND experience,

both of which you possess! Thanks for your input. Your input helps to remind me

to let the newbies know the following:

To the newbies, you too will have the experience one day. For now you will have

to use formulas or methods until you get the hang of it. Eventually some of you

will use logic. Some will continue to use methods that I show you on this site

or that you learn from others or books.

What matters is that you arrive at the same destination!

Some of us crawl, others walk, some swim and yet others take a jet!

As long as we all arrive at Rightmathanswer, USA the patient will be be okay.

AS we become more experienced you will see that the speed at which you arrive at

the same answer will determine customer service, pharmacy operations or decide

between life or death.

Passing the national exams will take you to early stages of formula and methods,

and experience brings you to teh realm of logic; which will be a slow crawl, but

giving you the foundation to run, skip, jump, leap and eventually fly (just

like Karin!).

Good luck to all,

Jeanetta Mastron CPhT BS

F/O

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> > From: krshy29 <krshy29@ >

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> > Subject: [JeanettasPTCBStudy Group] ??? mls: solve difficult problem

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hypochlorite) . How many mls of the stock solution are needed?

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[Guest guest]

I think you may have gotten me confused with someone else writing to you.

I understood perfectly!

From: krshy29 <krshy29 (DOT) com>

Subject: [JeanettasPTCBStudy Group] ??? mls: solve difficult problem

JeanettasPTCBStudyG roup@groups .com

Date: Monday, April 6, 2009, 11:43 PM

A physician orders a liter of half strengh Dakin's Solution. On hand in the

pharmacy is full strength Dakin's Solution (0.5% sodium hypochlorite) . How many

mls of the stock solution are needed?

 

[Guest guest]

I didn't want to do an injustice to the author of my book.  I think this is the

right formula, just the wrong number was added.

FV  x  %  =  gm or ml

1000 x 0.5 = 500

or the allegation method.

Sorry for the confusion.

From: krshy29 <krshy29 (DOT) com>

Subject: [JeanettasPTCBStudy Group] ??? mls: solve difficult problem

JeanettasPTCBStudyG roup@groups .com

Date: Monday, April 6, 2009, 11:43 PM

A physician orders a liter of half strengh Dakin's Solution. On hand in the

pharmacy is full strength Dakin's Solution (0.5% sodium hypochlorite) . How many

mls of the stock solution are needed?