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.

chaconsara32
Feb 1, 2018

#1**+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

CPhill
Feb 1, 2018

#2**+2 **

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 !!!!

CPhill
Feb 1, 2018

#3**+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

#7**+2 **

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.

Melody
Feb 2, 2018

#8**+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

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

Melody
Feb 2, 2018