How much does one sucrose molecule weigh in grams?

5 months ago342.3

5 months agohm, that would be an entire mole of sucrose, so to find 1 molecule you'd just divide that by avogadro's remember that a molecule is very very small

5 months ago1.76 x 10^21

5 months ago342.3/(6.022*10^23) = ?

5 months ago5.68 x 10^-22

5 months agogood

5 months agoFind the number of ibuprofen molecules in a tablet containing 200.0 mg of ibuprofen (C13H18O2).

5 months agowould I find the molar mass first of each element

5 months agoyeah, you'd add up 13(molar mass of carbon) + 18(molar mass of hydrogen) + 2(molar mass of oxygen) to find the molar mass of the whole compound then it's 200.0 mg/1000 to convert this to grams; then divide by the molar mass from the first step to get moles, then multiply by avogadro's to get molecules

5 months ago7.834 x 10^26

5 months agowhat did you get for the molar mass of ibuprofen

5 months ago260.1898

5 months agowait no

5 months agothe molar mass of ibuprofen should be closer to 206 not 260

5 months agoyeah i rechecked my calculation I am getting 206.2852 now

5 months ago13(12.0107) + 18(1.00794) + 2(15.9994) = 206.28082g

5 months agoyeah that's fine, it's within rounding error

5 months agoafter that it's just ( (200mg/1000) / 206.2852 ) * 6.022e23

5 months ago5.839 x 10^20

5 months agogood that should be your solution

5 months agoWhat is the mass of a sample of water containing 3.55×10^22 molecules of H2O?

5 months agothis would be the opposite right take the molar mass of h20 and multiply by the given

5 months agothink about the units of molar mass g/mol; this doesn't have molecules in it since we have molecules we have to convert 3.55×10^22 molecules to moles first, then multiply by the molar mass of water

5 months ago2.13781 x 10^46

5 months ago3.55×10^22 / (6.022e23) * 18.02 = ?

5 months agoremember, molecules to moles --> divide by molar mass

5 months ago|dw:1539661417976:dw|

5 months ago1.06

5 months agogood that's what i got too

5 months agoyeah that's what i got too

5 months agoWhat is the mass percentage of each element in the compound Al2O3?

5 months agoDid you get 9% for Al if I did this right

5 months agohm, I feel like it should be more than that molar mass of aluminum = 26.981538g molar mass of oxygen = 15.9994g total mass: 2(Al) + 3(O) = 2(26.981538g) + 3(15.9994g) just the aluminum: 2(26.981538g) so aluminium only/total mass * 100 should give the percentage

5 months ago36

5 months agoand then for O it would be

5 months ago:

5 months agohm, I got something a bit different

5 months ago32 for oxygen

5 months ago2(26.981538) / [2(26.981538) + 3(15.9994)] = 52.9% composition of aluminum then for oxygen it's just 100% - 52.9% since we only have two components, aluminum and oxygen

5 months agoOh I see.

5 months agoso it would be 52.9 , 47.1

5 months agoyes, 52.9 for Al and 47.1 for O

5 months agoThis is what I got. When going from grams to moles, it has nothing to do with avogadros # does it

5 months agonot quite have you tried calculating the molar mass of CaCO3?

5 months agoYes I got 100.091

5 months agoand then divided the total by the number of grams given in the problem

5 months agogood, so you'd divide 25.45g/100.091g to get to moles, then you'd multiply by 3 since each molecule of CaCO3 has 3 mol oxygen

5 months agobut I got 48 in the beginning for the molar mass. Would I still multiply by 3?

5 months ago48? no the molar mass is 100.091

5 months agono I mean when calculating the molar mass of the entire thing I already incorporated oxygen as being 3. In other words 16 * 3 . so why do I need to multiply by 3 again

5 months agoyou have to incorporate oxygen into the molar mass to get 100.091 after you have moles, you have to multiply by 3 because it's asking for the number of moles of oxygen

5 months agoit's a completely separate calculation

5 months agooh okay I get it so I have to multiply by 3 in the beginning regardless because of the total molar mass but because its asking for oxygen I have to multiply by 3 again

5 months agoyes

5 months ago.7628

5 months agogood that's it

5 months agowell you have 100g of the entire compound, and it says its composed of 40.0% carbon, 6.70% hydrogen, 53.5% oxygen, right? so how many grams of carbon hydrogen and oxygen do you have

5 months agostill there? since the percentages are out of 100 it's just 40.0g carbon, 6.7g hydrogen, 53.5g oxygen

5 months agothen you'd convert these masses to moles

5 months ago40/100=.4 6.7/100=.067 53.5/100=.535

5 months agohm, that's not how you convert grams to moles, remember g --> moles, divide by molar mass

5 months agobut would I do 100 divded by molar mass or like the other number for the elements like for carbon 40/molar mass

5 months agowe started with 100g of a compound with composition 40.0% carbon, 6.70% hydrogen, 53.5% oxygen naturally, if we want to know the masses of carbons, hydrogens, and oxygen, we would do 100g * 40.0% = 40g of carbon; same reasoning gives us 6.7g hydrogen and 53.5g oxygen

5 months agonow, we want to convert 40g of carbon to moles by dividing by the molar mass of carbon, 6.7g hydrogen to moles by dividing by the molar mass of hydrogen and 53.5g oxygen to moles by dividing by the molar mass of oxygen

5 months ago40/12.011=3.33 6.7/1.0079=6.65 53.5/16=3.34

5 months agoawesome, this gives us the molar ratio between the compounds, but since we want whole numbers, we divide all three quantities by the smallest quantity of the three so in simpler words, since the smallest number out of those three is 3.33, divide all three quantities by 3.33

5 months ago3.33/3.33 = 1 6.65/3.33 = about 2 3.34/3.33 = about 1 so the molar ratio is CH2O = your empirical formula = your sol'n

5 months agoanyway I haven't eaten all day so i'm gonna grab a quick bite, be back in an hour ish if you're still up for more hw

5 months ago