Hello,
I am having some trouble finishing this problem from my textbook and would like some insight on the problem. We are looking for the molecular formula of a hydrocarbon. So, if we let x = number of C atoms and y = number of H atoms then we need to find ##C_xH_y##. From the problem...
Moles are proportional to volume. There is 1000 cm3 of gas (carbon dioxide gas plus water vapour) after the reaction, and 200 cm3 of water vapour after the carbon dioxide has been absorbed. Therefore, there is 800 cm3 of carbon dioxide. Since the stoichiometric ratio of carbon dioxide to the...
number of moles of CO2 =0.089moles (using 2/22.4)
number of moles of water = 0.067 (using 1.205/18)
I know that all the carbon from the hydrocarbon is in the CO2
and all the hydrogen from the hydrocarbon is in the water and water creates x2 hydrogens
so number of moles of C : H = 0.089 ...
I am doing some theoretical free-lance work on prospects of chemical rocket fuels with unusually high heating values and specific impulses.
One of my latest interests is prospects for using fuels with molecules made of one carbon atom and 5 or more hydrogen atoms. Specific examples I am...
Homework Statement
Homework EquationsThe Attempt at a Solution
C=C double bonds means that it is not an Alkane because an Alkane is saturated hydrocarbon. So the answer should be from A, B or C.
In combustion science, typical flames that are studied are premixed or diffusion flames, where a stream of methane, propane or some other fuel is released to an atmosphere of air or oxygen and ignited. Another scenario is a "pool fire", where a puddle of volatile solvent is burning in air and...
I have a work assignment where I'm supposed to calculate the transmittance of blackbody radiation through liquid n-heptane, and I have data of the heptane's absorption coefficient on the wavelength interval from 2.6 to 15 micrometers (it has significant peaks at about 3.5 ##\mu##m, 7.0 ##\mu##m...
I'm currently in the process of selecting gas mixtures to calibrate a gas chromatograph. One of the gas mixtures I'm interested in has the following composition by percent volume:
methane (CH4): 95%
carbon dioxide (CO2): 1%
butane (C4H10): 1%
acetylene (C2H2): 1%
nitrogen (N2): 2%
The gas...
I have 2 queries and would be great if someone can lead me to some specific answers -
1. Is it possible to oxidise a complex hydrocarbon like Ethanol or Gasoline in a non-combustible but exothermic reaction?
2. If this kind of oxidation is possible, what would be the best catalysts to achieve...
Hi,
We are currently working on a small-scale Fischer-Tropsch process.
The modeling software we are using is HYSYS (Aspen).
We want to produce X barils of oil / day using syngas (H2:CO ratio 2:1) using cobalt catalysts.
The problem we are currently facing is that we do not have the kinetics...
Homework Statement
one gram of each of the following gases is introduced into a 10 L container at 25 degrees C
a) propane
b) ethane
c) methane
d) pentane
which gas will consume the greatest mass of oxygen upon complete combustion?
The solutions says that the right answer is D. I do not know...
Dear PF Forum,
I have read this link in Wiki.
But I don't understand what it means. Can someone help me?
https://en.wikipedia.org/wiki/Heat_of_combustion
A: Heat of combustion of CH4 is 50.09 MJ/kg
https://en.wikipedia.org/wiki/Standard_enthalpy_change_of_formation_(data_table)
B: Enthalpy of...
Dear PF Forum,
First of all, I'd like to thanks PF Forum for giving me invaluable answers all this time.
Now, I have a "situation" here.
My church wants to conserve environment by changing cooking oil into biodiesel from its parishioners
I'd like to know how effective this effort is.
I have...
Dear PF Forum,
Actually I've never visited chemistry forum. It's cosmology and SR that interests me.
Tomorrow at Thursday 30th July, 14:00 GMT. I have to present a service (religion) about global warming.
But there's some facts that I need to know fast.
Can anyone help me?
What is the formula of...
Hi everybody!
The problem which I am dealing with is surprisingly very well depicted in open source lecture notes made in October 29th of 2012, titled: " MAE 5310: COMBUSTION FUNDAMENTALS", available on the web...
Homework Statement
Combustion of hydrocarbon X in excess oxygen produces 0.66g of carbon dioxide, and 0.27 g of water. At room tempertaure and pressure , X is a gas with density 1.75gdm^-3 . What could the molecular of X be?
What is the ans ? i only managed to get the empirical formula is CH2...
Homework Statement
The Attempt at a Solution
The answer is supposed to be D but I can't figure out why, my method gave me B
counting the number of points in the longest chain there are 7 and there are only single bonds so without the branches I have heptane. there is a ethyl attached to the...
Homework Statement
The Attempt at a Solution
The answer is supposedly C but I can't figure out why its not E.
first I count the number of C in the longest chain. There are 7 C and there are only single bonds so the the root and suffix is heptane. there is a chain with one C (methyl) and one...
Homework Statement
A sample of a hydrocarbon is combusted completely in O2(g) to produce 19.65gCO2(g), 4.023gH2O(g), and 280kJ of heat.
Calculate the value of ΔH∘f per empirical-formula unit of the hydrocarbon.
Homework Equations
None I know of
The Attempt at a Solution
Previous calculations...
Homework Statement
A gaseous hydrocarbon X had an approximate molecular weight of 57. It reacted with both bromine and dilute permanganate solutions. Give the structural formula of the only 3 compounds consistent with this information.
X was treated with hydrogen bromide, and the resulting...
Homework Statement
Which would have the most negative heat of combustion? Consider only the best conformer.
cis-1,3-dimethylcyclohexane
trans-1,4-dimethylcyclohexane
Homework Equations
The more negative the heat of combustion, the more exothermic the combustion.
We are...
Afternoon all,
I am interested to hear any and all suggestions as to how one would go about modelling the rise in temperature on the "safe" side of a wall, after a given time period over which the other side was exposed to a hydrocarbon pool fire.
The configuration I have been looking at...
I am working on a project about pollution emission, but I am not a chemist. I am seeing the units ppmC, ppmC3 and ppmC6 almost everyday, and I have trouble understanding what they stand for. The only definition I get is "Parts per million hydrocarbon concentration expressed as methane (for...
Homework Statement
In an engine test the dry exhaust gas analysis is CO2: 5.27%; O2: 13.38%: N2: 81.35%.
Assuming that the fuel is a pure hydrocarbon of the form CxHy, and that it is completely
burnt, calculate the ratio, by mass, of carbon to hydrogen in the fuel and the air to fuel...
Homework Statement
Identify any errors in the name of each hydrocarbon?
2,4-diethyloctane
The Attempt at a Solution
I drew a complete diagram of the molecule but I still do not understand what is wrong with it.
Thank you.
Without introducing any other atoms or double bonds into the chain? (just replace the halogen with a hydrogen atom). Assume for now that the halogen was introduced in the middle of the carbon chain.
Homework Statement
A gaseous hydrocarbon weighing 0.185g occupies a volume of 110.cm^3 at 26 celsius and 743mmHg. what is the molecular weight of this compound?
Homework Equations
PV=nRT
The Attempt at a Solution
i have no idea where to start ;(
Homework Statement
Q. A Hydrocarbon (CnHm) is burned completely in oxygen to produce a mixture of CO2 and H2O. The total pressure of mixture is 1.200 atm and partial pressure of H2O is 0.686 atm. What is empirical formula of Hydrocarbon
Homework Equations
pV=nRT
pa/ptotal =...
I just have a quick question about hydrocarbon nomenclature:
When picking the "parent chain", I know that you're supposed to pick the one with the longest carbon chain... does the parent chain always have to have the double/triple bonds? Or can the double/triple bonds be located in a sidechain...
I was checking the NIST site with their Hydrocarbon line database
search utility, and the frequencies of the lines for CH, CH2, and CH4
are on the order of 10^11 Hz approximately. That leads to wavelengths
that are much larger than the visible region. Am I reading the search
results...
Homework Statement
Name the following compound:
CH3CH2C(CH3)2CH(CH2CH3)CH2CH2CH3
It's an alkane (Is there a way to see that it's an alkane when it's in this format?)
Homework Equations
The Attempt at a Solution
I really have no idea where to start. I can name compounds...
[b]1. I have a relatively simple question, but I can't think of the answer.
A high bp hydrocarbon (X) is obtained by the fractional distillation of crude oil. (X) is then heated in the presence of silicate materials. only 3 new hydrocarbons were from this proces.
All I want to know is what...
Hi i am a IB student currently working on my extended essay in the field of chemistry and was wondering if anyone could suggest where i could find the enthalpy profiles for specific hydrocarbons including standard enthalpy changes for fuels such as: petroleum, diesel, ethanol, methanol...
Homework Statement
0.1 dm^3 of a gaseous hydrocarbon may require 0.45 dm^3 of oxygen for a complete combustion to give 300 cm^3 of Carbon dioxide. All volumes are measured in the same environment. Calculate the molecular formula of the hydrocarbon.
The Attempt at a Solution
i tried...
This problem was proposed to us by our Chemistry professor. Consider a sample of a hydrocarbon at 0.959atm and 298K. Upon combusting the entire sample in oxygen, you collect a mixture of gaseous carbon dioxide and water vapor at 1.51atm and 375K. This mixture has a density of 1.391 g/L and...
Hi,
I'm just starting high-school organic chemistry and as is customary I've begun with nomenclature of organic compounds. Till now I've covered aliphatic hydrocarbons and will be starting on nomenclature of functional groups. The following problem from K.L. Chugh's Senior Chemistry Vol. II...
Hey everyone,
I have this problem to solve:
A hydrocarbon (CxHy) contains 92.3% of Carbon and 7.7% of Hydrogen.
1) What is its molar mass, if the density of its smoke to the air is d=2.69 ?
92.3/7.7 = 12
So 12x=y
This is the first equation. I have to find a second one to find what is x...
While studying chemical bonding for methane,ethyne etc., I have made the following assumption to help me to remember the sigma bond, pai bond, and hybrid orbitals.
1. Every single covalent bond around a carbon atom is a sigma bond.
2. Only one of the bond in double and triple covalent bond...
In a closed system a hydrocarbon is burnt. The products which are produced have a temperature of X degree celcius. What will happen once the temperature of whole of the system becomes X degree celcius? How will it affect the burning of hydrocarbon?
Thanks a lot for any help.
Abd. S.
Hello,
I was quite curious about this one here...
If I were asked to draw a structural diagram, for example, of trimethylbutane, where would I put the three branches of methyl. When they don't specify the location of the branches what does one do? I'd normally be expecting something like...
Considering that fats have long hydrocarbon chains, what do theses terms mean when applied to fats
does this mean the the longer the hydrocarbon chain is the more space t will occupy. I am not sure can i have some help
Considering that fats have long hydrocarbon chains, what do theses terms mean when applied to fats
does this mean the the longer the hydrocarbon chain is the more space t will occupy. I am not sure can i have some help
http://www.newscientist.com/news/news.jsp?id=ns99994552
Maybe is true after all that we are all "sons of the stars"
This is a strong evidence that life is spread throughout the cosmos, don't you think?