***Chemistry - Fall 2005***

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Who else is taking Chemisrty this semester? I thought maybe we can check in with each other, and help each other out.

If there is enough of us maybe we can even get a sticky.

I am taking Health Science Chemistry 1.

ok, someone make sure i'm doing this correctly, please! :)

d = ?

v = .52 l

m = 500 mg

i have to convert l to ml and mg to g.

so, i have come up with the math sentence:

d = .5 g

---------

520 ml

now, if i'm putting this in my calculator correctly, i'm coming up with: 9.615384615 -04. normally i would put 9.62 g/ml as my answer, but the -04 is confusing me.

i'm not sure on this type of question if i would use significant #s. if so, the answer would be 10.

:confused:

:bowingpur tia! :flowersfo

i got 961.53 and yes i would make it 10 if using sig figs which we always seem to do for our homework. although i didn't convert like you said to.i just divided mass/volume per the density formula. i think i'm just more confusing than helpful!! just ignore me!! :p

ctrnstudent-glad you like it!! i find it funny and helpful!! :rotfl:

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Specializes in Operating Room.

well, on this particular set of problems, it says to convert to g or ml first. lol :)

i may be almost ready for my 1st test tomorrow.... :crying2:

i got 961.53 and yes i would make it 10 if using sig figs which we always seem to do for our homework. although i didn't convert like you said to.i just divided mass/volume per the density formula. i think i'm just more confusing than helpful!! just ignore me!! :p

ctrnstudent-glad you like it!! i find it funny and helpful!! :rotfl:

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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.

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Specializes in Operating Room.
I could be totally screwed up in which case nevermind and have a nice day. :) I'm off to class.

:rotfl: :rotfl:

I hope the instructor doesn't give a confusing problem like that ugggh lol

ANOTHER QUESTION!!!!

When you are finding Mass (m=vd) or Volume (v=m/d) how do you write your answer?

is it like 13.6 g/ml or just 13.6 g?

or is volume just mL or mL/g

I know density is g/ml so, I'm just wondering...

2 classes b/4 a test is not enough!

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Specializes in Operating Room.

oops I moved on, but found another question..uggh

When a question as for the density, but gives you a mass of a block of 1896g, and the dimensions of a block....what do you do??????

The dimensions are 8.4cm by 5.5 cm by 4.6 cm. We didn't go through this in class, so I'm not even sure it will be on the test, but you never know.

The worksheet I downloaded off of the internet says, "hint: find the volume of a block first)

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oops i moved on, but found another question..uggh

when a question as for the density, but gives you a mass of a block of 1896g, and the dimensions of a block....what do you do??????

the dimensions are 8.4cm by 5.5 cm by 4.6 cm. we didn't go through this in class, so i'm not even sure it will be on the test, but you never know.

the worksheet i downloaded off of the internet says, "hint: find the volume of a block first)

ok this one i totally know. you need to find the volume by doing 8.4cm x 5.5cm x 4.6cm=212.52cm (lengthxwidthxheight or lengthxlengthxlength). so now you have the volume!!! :biggringi

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Specializes in Operating Room.
ok this one i totally know. you need to find the volume by doing 8.4cm x 5.5cm x 4.6cm=212.52cm (lengthxwidthxheight or lengthxlengthxlength). so now you have the volume!!! :biggringi

thanks, i wondered that. i kept searching too... i found a worksheet that actually had the answers & it proved my thoughts correct.

the answer would be in cm3 though, at least that is what is on this worksheet. is it just for that problem, or does that sound correct to you?

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Thanks, I wondered that. I kept searching too... I found a worksheet that actually had the answers & it proved my thoughts correct.

The answer would be in cm3 though, at least that is what is on this worksheet. Is it just for that problem, or does that sound correct to you?

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

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ok this one i totally know. you need to find the volume by doing 8.4cm x 5.5cm x 4.6cm=212.52cm (lengthxwidthxheight or lengthxlengthxlength). so now you have the volume!!! :biggringi

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.

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:rotfl: :rotfl:

I hope the instructor doesn't give a confusing problem like that ugggh lol

ANOTHER QUESTION!!!!

When you are finding Mass (m=vd) or Volume (v=m/d) how do you write your answer?

is it like 13.6 g/ml or just 13.6 g?

or is volume just mL or mL/g

I know density is g/ml so, I'm just wondering...

2 classes b/4 a test is not enough!

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

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Specializes in Operating Room.
mass= g vol = mL the density is equal to g/mL because m/v=d

That's what I thought. I guess I'm just getting myself worked up over my first exam tomorrow.

2 classes doesn't seem enough to have an exam already! :chair:

However, after tomorrow, I'll only have 6 more weeks of this class. :)

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hmm my teacher didn't make us do cm3. i should ask on that one! :uhoh3:

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