CTRNstudent

Congratulations! 101.2 That's 4 significant figures or 1.01 x 10(exp2) LOL-----Keep it up!

I think that post was from 2004.

Soleilpie- My professor says that they were probably just showing the relation between the units- the answer was exactly the same no matter what the units were. So no conversion was necessary. I found a good website chemistry.about.com/od/generalchemistry any topic your interested in just type it in the "search". Fun2care- I tried stoichiometry and it had 1-49 results.

mass= g vol = mL the density is equal to g/mL because m/v=d

the answer would be in cm3 and the 212.52 you have to change into 2 significant figures so the answer would be 2.1 x 10(exp 2) cm3 or ml ----------i think.

1 cm3 is equal to 1 mL is that what you are asking? No conversion math necessary

OK- I'm going to give this a try 500mg x 1g/10(-3)mg= 500g x 10 (-3) or .500g .52 L x 10 (-3)mL/1L= .52 x 10 (-3) or 520. mL now .500g/520. mL = 0.000961538 or 9.6 x 10(-4) g/mL As far as the significant figures- When looking at 500 with no decimal at the end 500= 1 significant figure. right And the law of div./mult w/ sign. figures says to go w/ the least # of significant figures. So I think you would have to change the answer to 10 and 10 only has 1 signf. figure. however I think you still have to have the x 10 (-4) added to your answer. = 10 x 10 (-4) g/mL or I could be totally screwed up in which case nevermind and have a nice day. :) I'm off to class.

:chuckle that's funny paula. thanks.

ooooooooh! Thanks Fun2care. Upon closer examination, I see Moonepie also explained that in her answer. :imbar And this is only chapter 1? I have taken many of my other pre-reqs. and really enjoyed them. I knew this would not be my forte. Pray for me.

Thanks Moonpie. I now have the answers. This is what they are: The first one is 11.3 kg/m3- I don't understand why it is kg/m3 instead of g/mL - Do you?, The next one was set up just as you had it 1.2/.12 = 10g, The next one came out close to your answer, it was 5.04 x 10 (exp -5). I am going to go in early or check with the tutoring lab for some extra help. Luckily we are still on chapter one so I am going to try and stay on top of things. Fun2care - Thank you for your memorization techniques. I actually have no problem with remembering things like that. My concern is taking the word problems and actually trying to figure out how/if to plug them in to the equation and when you bring in the exponents do they remain negative depending on where they are? I have so many questions I can not wait to go back to class and have them answered. I am so glad you are all here. It's nice to see the posts of people who are ahead along with the answers I am sure they will help all of us.

Thanks Paula- Every bit helps. I'll keep my fingers crossed for you

:rotfl: Help! Ok, I have 3 problems I just can not figure out. 1. A sample of lead shot weighing 343.6 g was added to a graduated cylinder partially filled with isopropyl alcohol (enough to immerse the lead completely). As a result, the alcohol level rose 30.3 mL. What is the density of the lead in SI units? (the density of isopropyl alcohol is 0.785 g/cm3) 2. The RDA of calcium is 1200mg. Calcium carbonate contains 12% calcium by mass. How many grams of calcium carbonate are needed to provide the RDA of calcium? Honestly- I know the answer is 10 g but I can not tell you how to get the answer. 3. An office is 4.44m long, 3.48m wide, 2.53 m high. The avg density of air is 1.29 X 10 (exp -3). What is the mass (in kilograms) of the air in the office? Any help would be great. Thanks guys.

Hi. I'm taking Chemistry w/lab this fall also. I'm already chewing my fingernails. I took Biology this summer, loved it but chemistry looks confusing. It's great to have this forum hopefully we can help each other through.

Thank you for all your responses. This has been so helpful. I felt a little dumb asking the question "what does a CNA do?" but I'm glad I did. . Most CNA courses in CT seem to be fairly short, I think I can handle taking the course along with my pre-req. classes. L&D it seems like you do so much as a CNA, I imagine all that will change is your title, $ and opportunities.

Pardon my ignorance. What does a CNA do?