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Hello, I need help with this (and some other, I'm new at these type of problems):

1. On the label of a bottle of vinegar, the information appears: "acetic acid solution at 4% by weight". If the bottle contains 750mL of vinegar and its density is 1.006g / mL, calculate the mass of acetic acid contained in the bottle.

2. A hospital organized a blood donation event where 80 pints of blood were collected. The hospital expected to get 8 gallons of blood with the event. Has the goal been met?
1pt = 473mL
1 gal = 3785 mL

Also, I don't know if these include conversions but, conversions are one thing my brain doesn't seem to understand at all.

Feb 1, 2018

#1
+111326
+3

1. On the label of a bottle of vinegar, the information appears: "acetic acid solution at 4% by weight". If the bottle contains 750mL of vinegar and its density is 1.006g / mL, calculate the mass of acetic acid contained in the bottle.

Density  =  Mass / Volume    .....     which means that  .....

Volume * Density  =  Mass

So....for the liquid in the bottle we have that

750 ml  *  1.006 g / ml     =   Mass         [  the "ml"  cancels ]

750 *  1.006 g  =

754.5 g   ....   this is the mass ["weight "] of the liquid .....

And the acetic acid is 4%  of this

So........the  mass  ["weight"]  of the acetic acid  is 4% of this...so

.04 * 754.5  =

30.18 g

Feb 1, 2018
#4
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I just have one more question, where did you get the .04?

chaconsara32  Feb 1, 2018
#5
+111326
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4%   = 4/100 =   .04

CPhill  Feb 1, 2018
#6
+62
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Oh, ok. hahah

Thanks again

chaconsara32  Feb 1, 2018
#2
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2. A hospital organized a blood donation event where 80 pints of blood were collected. The hospital expected to get 8 gallons of blood with the event. Has the goal been met?
1pt = 473mL
1 gal = 3785 mL

80 pints  =    80 * 473 ml  =  37840 ml

8 gal  =      8 * 3785   = 30280 ml

The goal has been met  !!!!

Feb 1, 2018
#3
+62
+1

Thank you so so much!

I struggle with this and most of the times I don't know where to start.

chaconsara32  Feb 1, 2018
edited by chaconsara32  Feb 1, 2018
#7
+109519
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2. A hospital organized a blood donation event where 80 pints of blood were collected. The hospital expected to get 8 gallons of blood with the event. Has the goal been met?

Why would you convert to metric?

There are 8 pints in a gallon   (I expect you are from the U.S. and you are supposed to know this)

so 8 gallons = 64 pints

They expected 64 they got 80 so YES they were happy :)  The goal was not only met it was exceeded.

Feb 2, 2018
#8
+109519
+2

1. On the label of a bottle of vinegar, the information appears: "acetic acid solution at 4% by weight". If the bottle contains 750mL of vinegar and its density is 1.006g / mL, calculate the mass of acetic acid contained in the bottle.

It is easy, you can cancel the mL units out !

The only other thing you need to know is that mass can be measured in grams

$$Total\;mass\;=750mL*\frac{1.006g}{1mL}=750*1.006g = 754.50g\\ Mass\;of\;acid\;\;=\frac{4}{100}*754.5g=30.18grams$$

.
Feb 2, 2018
edited by Melody  Feb 2, 2018