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I got this question wrong, and I'm not sure where my mistakes lie. Can someone show me what I'm not doing right and what the correct answers should be?

"Some states have reduced the legal limit for alcohol sobriety from 0.10% to 0.080% alcohol by volume in blood plasma.
a) How many mL of alcohol are in 3.0 qt of blood plasma at the lower limit?
[my work]
x qt/3.0 qt= .080 %
x qt= .24
.24 qt x 1 L/1.057 qt x 1000 mL/1L= 230 mL

b)How many mL of alcohol are in 3.0 qt of blood plasma at the higher legal limit?
x qt/3.0 qt= .10
x qt= .30 qt
.30 qt x 1L/1.057 qt x 1000 mL/1 L= 280 mL

c) How much less alcohol is in 3.0 qt of blood plasma with the reduced sobriety level?
280 mL
- 230 mL
= 50 mL

I think your only error is that you didn't convert percent to a decimal.
0.08%v/v means 0.08 mL alcohol per 100 mL plasma. That is the equivalent of 0.8 mL per 1 L and you had
3 qt x (1 L/1.057 qt)= 2.838 L
Therefore, 2.838 L x 0.8 mL = 2.27 mL in the 3 qts. You can get the same number if you divided your 0.08% by 100 at the beginning and leave the remainder of your solution intact. I hope this helps. Thanks for showing your work.

oh, thank you. i realized after i typed it that something about the percent wasn't right. that clears it up a lot.

You must realize, also, that 0.080% and 0.10% have only two significant figures; therefore, the answer will have only two s.f.

That means the answer to part (a) is 2.3 mL and the answer to part (b) is 2.8 mL. The difference between the two is 0.5 mL.

Well, isn't that just a pain in the significant figures? It's like they only want us to have a limited amount of fun. But don't worry, I'm here to make sure you're keeping things accurate and humorous. Just remember to pay attention to those little details, like converting percentages to decimals and keeping track of significant figures. Keep up the good work, and soon you'll be blowing away those alcohol sobriety questions faster than a breathalyzer can say "Whoa, slow down!" Cheers!

Yes, you are correct. In scientific notation, the number of significant figures is important. In this case, since 0.080% and 0.10% both have only two significant figures, the answer should also have two significant figures. Thank you for pointing that out.

Yes, you're absolutely right. When working with significant figures, it's important to match the precision of the given data. In this case, the original percentages only have two significant figures, so it's appropriate for the answers to have two significant figures as well. Thanks for pointing that out!