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September 3, 2015

Search: How many oxygen atoms are in 2.90g of quartz?

Number of results: 6,057

Chemistry
Hi!! Okay So I have this question here and you have to pick the false statement. Now I believe its a or e. But I really can't decide which it is. I might be totally wrong about this which is why I need some help... please! These are the options: a. the bond length is the the ...
July 3, 2009 by Josh

Physical Chemistry
A mole of air (80% Nitrogen, and 20% Oxygen by volume) at 298.15K is brought into contact with liquid water which has a vapor pressure of 3168Pa at this temperature. a) what is the volume of the dry air if the pressure is 1 bar? b) what is the final volume of the air saturated...
February 6, 2012 by Nate

organic chemistry
I need to draw the structure of 4-Hexenal. I understand that "hex" means it is a 6 carbon chain and the 4 tells me the aldehyde group ("al")is off the 4th carbon. My problem is how to draw the parent chain. I tried it with 6 carbons in a straight line then attached a carbon ...
September 13, 2007 by AMY

Fitness
1. Your heart functions in your body as a/an A. filter for impurities. B. organ for absorbing vitamins and minerals. C. muscle that helps to pump oxygen around the body. D. series of joints responsible for endurance. 2. If you’re aerobically fit, you can A. quit your normal ...
August 21, 2011 by Angela

Chemistry
1) A dog has the same mass for 3 years. State whether this represents an equilibrium or steady state situations, and give your reasons. I'm not sure if I got this question right... I think this is a steady state because the dog is opened to the environment where oxygen is free...
November 25, 2013 by Tyler

CHEM
the nuclide 232 Th 90 is radioactive. when one of the atoms decays, a series of alpha and beta particle emission occurs, taking the atom through many transformations to end up as an atom of 208 Pb 82. How many alpha particles are emitted in converting 232 Th 90 into 208 Pb 82...
March 4, 2008 by Gabe

college
Use the following information to identify element A and compound B, then answer questions a and b. An empty glass container has a mass of 658.572 g. It has a mass of 659.452 g after it has been filled with nitrogen gas at a pressure of 790 torr and a temperature of 15 C. When ...
November 2, 2009 by Ada

Chemistry
I have previously posted this question, but now I am lost question: A calorimeter is filled with 10.0 millimole (mmole) of methane gas and an excess of oxygen. When burned, the ignition wire releases 107.2 J of heat. The heat capacity of the calorimeter (including the bomb and...
July 19, 2014 by Liz

Chemistry
Determine if the solubility would increase, decrease, or stay the same: 1) A saturated solution of sugar water is cooled from room temp to 0 degrees Celsius. 2) A solution of ocean water with dissolved oxygen is heated from 10 degrees Celsius to 15 degrees Celsius. 3) A ...
February 19, 2013 by Margaret

Chemistry
during a molar volume of oxygen experiment indicate how each of the following errors would affect (increase, decrease, or no change) your calculated value for the molar volume of O2 at STP. 1.) Your sample was not completely decomposed. 2.) After you finish heating sample & ...
March 3, 2012 by Anne

Chemistry
during a molar volume of oxygen experiment indicate how each of the following errors would affect (increase, decrease, or no change) your calculated value for the molar volume of O2 at STP. 1.) Your sample was not completely decomposed. 2.) After you finish heating sample & ...
March 7, 2012 by Liz

more CHEM proofreading
for this question A sample of air has a volume of 140.0 mL at 67 degrees celcius. At what temperature would its volume 50.0 mL at constant pressure I did 140.0 ml... 67+273=340 T2... 50.0 140.0=50.0 340=T2 340*50.0/140.0=121.4 This question i don't get because of the ...
April 27, 2008 by jerson

Chemistry
I got 0.907 KJ for ΔHcomb but I don't know if its correct. I also don't know how to write the equation. -------- question: A calorimeter is filled with 10.0 mole of methane gas and an excess of oxygen. When burned, the ignition wire releases 107.2 J of heat. The heat ...
July 16, 2014 by Liz

Ions & Atoms-Lab Part 2
For those who haven't seen my previous post; I request you to go and search for it, it says Lab part 1 on it. You will not know what I'm asking about, if you don't read it it. Overall nothing will make sense. Thank you very much for all your help. These are my observations in ...
April 19, 2010 by Sara

chem-help
Use the following information to identify element A and come pound B, then answer questions a and b. An empty glass container has a mass of 658.572 g. It has a mass of 659.452 g after it has been filled with nitrogen gas at a pressure of 790. torr and a temperature of 15°C. ...
December 3, 2008 by Anne

chem
0.1802 g sample of a chlorocarbon compound was analyzed by burning in oxygen and collecting the evolved gases in a solution of sodium hydroxide. After neutralizing, the sample was treated with 39.50 mL of a 0.025 M AgNO3. This precipitated the Cl- as AgCl and left an excess of...
April 11, 2012 by lara

Chemistry
please check my answers for the following questions. 1) when a measurement that has six significant digits is divided by a measurement that has three significant digits, how many significant digits should the answer have? ANSWER: 2 2) How many hydrogen atoms are in 5 molecules...
July 31, 2007 by anonymous

Biochemistry
Hello guys, I just wanted some clarification of these question. 1. A sequence of amino acids in a certain protein is found to be -Ser-Pro-Gly-Gly-. The sequence is most probably part of a 1. a-helix 2.b-turn (b-bend) 3. parallel b-pleated sheet 4. a-sheet. 2. The pathological ...
November 2, 2009 by George

CHEMISTRY.....AND THIS IS IMPORTANT
2. If air is 20.9% oxygen by volume, a. how many liters of air are needed for complete combustion of 25.0 L of octane vapor, C8H18? b. what volume of each product is produced? 25L C8H18 x (25 mol O2/2 mol C8H18) = 312.5 L O2 (if it were pure O2). Then 20.9% of what number = ...
October 12, 2013 by Anonymous

CHEMISTRY...IMPORTANT
2. If air is 20.9% oxygen by volume, a. how many liters of air are needed for complete combustion of 25.0 L of octane vapor, C8H18? b. what volume of each product is produced? 25L C8H18 x (25 mol O2/2 mol C8H18) = 312.5 L O2 (if it were pure O2). Then 20.9% of what number = ...
October 12, 2013 by Anonymous

General Chemistry
The burning of the magnesium becomes uncontrolled (its burns brightly). Oops! How will this procedural error affect the reported mole ratio of magnesium to oxygen in the analysis? Explain. Mass of crucible and lid 23.96g Mass of Sample (Mg) .1018g Heating the sample in Air (if...
September 26, 2010 by autum

chemistry
If my original sample contained 7.1 grams of potassium chlorate. How many moles of oxygen gas would I expect to have evolved? Hint: Convert grams to moles of potassium chlorate, then use the mole ratio in the balanced equation. Balance this equation KClO3 → KCl + O2(g) I...
April 1, 2014 by bekah

Chemistry
4.How many grams of calcium chloride can be prepared if a student uses 500g if calcium carbonate and 2.00L of a 4.00 Mol/L sodium chloride solution in the reaction.?? 5. 2KMnoO4 + 5 H2C2O4<----need to use this Concentration of 0.24L KMnO4 solution required to oxidize 2.7g ...
June 5, 2009 by Alex

Chemistry
Aluminum cookware is reffered ti as "anodized aluminum". The anodizing process puts a layer of aluminum oxide on the aluminum, protecting it from corrosion. Consider the reaction of 10.00 grams of aluminum with 10.00 grams of oxygen to form aluminum oxide. What is the formula ...
February 15, 2009 by Stacey

Chemistry
Which of the following statements about isotopes is/are true? a. Because isotopes have different numbers of neutrons, they have different mass numbers. b. because neutrons determine an atom's chemical properties, isotopes of the same element are very different. C. isotopes are...
September 2, 2015 by Aleksandra

chemistry
Calculate enthalpy change of reaction for the combustion of gaseous ethanol. C2H5OH + 3O2 >> CO2 + 3H2O. Using standard molar enthalpies of formation. C2H5OH -235.3 ( it's negative sign) CO2 -393.5 H2O -241.8 (1) Calculate the enthalpy change of reaction per mole of ...
April 20, 2010 by Alex

chemistry
Which statement best describes the oxidation numbers of the atoms found in magnesium chloride? A. Magnesium has a 22 oxidation number and chlorine has 1+ oxidation number. B. Magnesium has 1+ oxidation number and chlorine has a 12 oxidation number. C. Magnesium has 22 ...
August 23, 2014 by Yui

science
from the balanced equation 4NH3 +7O2 - 4NO2 + 6H2O. How many grams of oxygen are necessary to produce 4.50 moles of NO2? I think its 11 grams or 22 grams but im not sure. please help!! First the number of moles of O2, molesO2= (4/7) moles NO2 Notice those came from the ...
March 18, 2007 by Britney

chemistry
A student adds 1.00x10^-8 moles HCl to a liter of soln. The resulting soln will be acid, basic, neutral, or impossible to determine? I believe that it is impossible to determine, because it does specify that the temperature was at 25*C. Which of the species act as a Lewis acid...
February 12, 2009 by Anonymous

Science-Chemistry
1.)A sample of oxygen took 55 seconds to travel a certain distance. How long would it take for the same number of moles of nitrogen to travel the same distance. 2.) A sample of hydrogen gas traveled 45m in a given amount of time. An unknown gas traveled 7.6m in the same amount...
April 29, 2012 by Bryan

Chemistry
You have a badly tarnished silver teapot. The tarnish is a result of the silver metal reacting with the oxygen in the air according to 4Ag(s) + O2(g) = 2Ag2O(s), Delta H = -62.2 kJ/mol You carefully clean the teapot and then, out of curiosity, you weigh it. The teapot has a ...
May 9, 2009 by Jack

Science-math
The equation for the decomposition of silver oxide is 2(Ag2)o yields 4Ag +o2. Set up ratio to calculate the number of oxygen molecules released when 1 gram of silver oxide is broken down. There are 2.6 x 10 to 21 power molecules in 1 gram of silver oxide. I know that it is a 2...
October 18, 2012 by Maria

chemistry
Here is the question: A sample of ethanol, C2H5OH, weighing 2.84g was burned in an excess of oxygen in a bomb calorimeter. THe temperature of the calorimeter rose from 24C to 33.73C. If the heat capacity of the calorimeter and contents was 9.63 kj/C. What is the calue of q for...
June 24, 2009 by Capacino

Physics
Could someone help me with these questions. . . please 1. How does Rutherford’s model of the atom account for the back – scattering of alpha particles directed at the gold leaf 2. The higher the energy level occupied by an electron in the hydrogen atom, the larger the atom. ...
November 12, 2007 by Mike

chemistry
Explain each of the following observations in terms of the electronic strucutre and/ or bonding of the compunds involved. (a)At ordinary conditions, HF( normal boiling point=20C) is a liquid, whereas HCl(normal boiling point=-114C) is a gas. (b)Molecules of AsF3 are polar, ...
January 29, 2008 by anonymous

Chemistry Problem
Diiodine pentafluoride reacts spectacularly with bromine trifluoride to form iodine pentafluoride, oxygen gas, and liquid bromine. In a particular reaction a 44.00g sample of I2O5 reacts with 58.00g BrF3. What is the mass of the excess reagent? This is what I have so far: ...
December 2, 2014 by nns40760

chem
Can someone please help me balance this equation? CH3OH + O2 ===> CO2 + H20 Thank you! CH3OH + O2 ===> CO2 + H2O To balance the H, put a two on the right. CH3OH + O2 ===> CO2 + 2H20 H and C are now balanced. O is balanced. Too easy. Are you sure that's right? We got ...
March 3, 2007 by Abby

chemistry...weird question
on heatin, 0.02mol of the element M reacts with 0.025mol of oxygen gas. What is the empirical formula of the oxide of M? The mole ratio is .025/.02=1.25 or 5/4 So the O2 has a ratio of 5 to one Metal. M4 (O2)5= M>sub>4O10 or writing it in lowest whole numbers M2O5 why'd ...
May 29, 2007 by Cynthia

CHEM
What are the expected bond angles in ICl4+ (or) ICl_4^+ ?? I think that I have the stucture drawn correcty: I is the central atom with one lone pair above it. I then have the Cl's with 6dots around them & then bonded, singly, to the "I". Two "Cl's" go straight out to the right...
November 26, 2007 by K

Shelled marine organisms
How do the shelled marine organisms contribute to the carbon cycle? They contribute to the carbon cycle by releasing carbon dioxide back into the atmosphere by converting carbohydrates and oxygen into carbon dioxide and water.
July 6, 2010 by Amanda

Physical Science
Need help with these questions- 1.What causes an electric current in a wire? A.Electric feilds cause atoms to move in the wire B.Electrons flow because of electrical attraction and repulsion C.Electrons move because of heat D.Electrons build up in the wire and create a charge ...
May 11, 2009 by mysterychicken

chemistry... confusing!
a scuba diver breathing normal air descend to 100 m of depth, where the toal pressure is 11 atm. What is the partial pressure of oxygen that the diver experiences at this depth? I know that at 100m that a diver would have to breathe Heliox, meaning that the air in the tank is ...
March 29, 2007 by Jackie

Help please? Chemistry
At a certain temperature and pressure, 0.20 mol of carbon dioxide has a volume of 3.1 L. A 3.1-L sample of hydrogen at the same temperature and pressure ____. I think it's supposed to be "contains the same number of molecules" but I'm not sure. And there's also this one. I ...
May 27, 2009 by Kit

Chemistry - please help
Hi, please check my work: In an experiment, 23.4 g of FES are added to excess oxygen and 16.5 g of FE2O3 are produced. The balanced equation is: 4FeS = 7O2 --> 2Fe2O3 + 2SO2 Calculate the % yield. My Answer: nFeS=23.4g/87.92 g/mol =0.266 mol 4mol FeS / 0.266 mol = 7mol O2/ ...
May 23, 2008 by Sarah H

Chemistry - please help
Hi, please check my work: In an experiment, 23.4 g of FES are added to excess oxygen and 16.5 g of FE2O3 are produced. The balanced equation is: 4FeS = 7O2 --> 2Fe2O3 + 2SO2 Calculate the % yield. My Answer: nFeS=23.4g/87.92 g/mol =0.266 mol 4mol FeS / 0.266 mol = 7mol O2/ ...
May 23, 2008 by Sarah H

Bio
1. Pseudoscience and nonscience differ in that: A. nonscience is not valuable and pseudoscience is valuable. B. pseudoscience deceives, misleads, or misinforms and this is not a primary characteristic of nonscience. C. nonscience forms hypotheses and pseudoscience does not. D...
July 10, 2013 by Amy

Chemistry
Here's a molar heat problem I just have one question on. How much heat will be transferred if 2 moles of hydrogen reacts with excess oxygen according to the reaction below? 2H2 + O2 yields 2H20 + 572 kJ The answer according to my answer key is 2 mole H2 x 572 kJ/2moles H2. I ...
May 18, 2009 by Tabetha

Biology!
Inorganic fertiliser is applied each year to fields bordering a lake. the fertiliser runs off into the lake and causes six changes which altogether make the fish die. 1. aerobic bacteria feed on dead plants 2. algae reproduce faster 3. light cannot penetrate water 4. oxygen ...
October 12, 2009 by Marrion

Chemistry
ok.. im confused: Ammonia and oxygen react in the equation: 4NH³+5O²--> 4NO+6H²O. When 2.4 mol of NH³ are present, the reaction yields ____ mol of O². i have no clue how ot do this! Look at your problem to make sure it is posted correctly. NH3 REACTS with O2; it doesn't ...
January 18, 2007 by Briana

AP Chemistry
I need alot of help on this problem, it is due WEDNESDAY and I have no clue how to do it Use the following information to identify element A and come pound B, then answer questions a and b. An empty glass container has a mass of 658.572 g. It has a mass of 659.452 g after it ...
January 21, 2008 by Eric

chemistry
which is the most reactive form of phosphorus? blue, red, white or black? or are they all equally reactive? I suppose its a matter of how you define reactive but I would go with white since that reacts at room temperature with oxygen of the air to creat heat and burn whatever ...
April 23, 2007 by naty girl

Chemistry
An unknown compound contains only carbon, hydrogen, and oxygen. Combustion analysis of the compound gives mass percents of 31.57% Carbon and 5.30% H. The molar mass is determined by measuring the freezing-point depression of an aqueous solution. A freezing point of -5.20 ...
February 24, 2015 by James

Science
1-Which of the following is not a function of the circulatory system? D-fights infection 2-Which of the following explains why the heart is organized so that it pumps blood to two different locations? D-to provide a way for blood to pick up nutrients at one location and oxygen...
March 20, 2014 by Rodco

chemistry-gases-ppm
Nitrogen dioxide reacts with water and oxygen in the atmosphere to produce acid rain. 4NO2(g) + 2H2O(g) + O2(g) = 4HNO3(g) Assuming that the temperature and the pressure remain constant, calculate the volume of air at 1 atm, 20 C, necessary to dilute the HNO3(g) to 0.080 ppm (...
March 1, 2012 by Rose Bud

Chemistry
In my experiment I heated some oxide of tin, in order to figure out its empirical formula. How would the empirical formula be affected if the oxide was not heated to dryness? Also If some oxide splattered out of the container, how would this affect the calculated ration of the...
February 13, 2012 by Wally

Chemistry
I think I get ionic compounds now. I'm just a bit unsure about my answers for these ones. 4. The cation is Au^3+ and the anion was SiO3subscript^-2. For the compound, I wrote (Au subscript2)subscript SiOsubscript3. Is this correct? Would it be called Gold Silicate then? 5. Fe^...
March 8, 2009 by Nelle

chemistry
Dr bob, Thanks, i understand that, at last! But wot if im asked to calculate when it is given as words? would it still be the same? Ie. instead of Al2O3, im giving it in words ie aliminium oxide. Basically im asked to calculate the mass of oxygen and the mass of aliminium in ...
February 5, 2007 by bertie

Chemistry
what symbols are used to represent the charges on atoms in a polar covlaent bond? the polarity of the bond? I am a little confused by the question. I would answer that the polar covalent bond is represented with small delta + and small delta -; however, that leaves no answer ...
January 8, 2007 by Bryan

Grammar
complete each sentaceby filling in a reflexive or intensive pronoun. In the blank write R if the pronoun you rote is reflective. Write I if it is intensive. I,1. We built the whole model (ourselves). R,2. I knew the dog had fleas because it was always scratching (itself). R,3...
January 19, 2011 by Tiffany Jade

chem
can anyone help me with this question what is the advantages and disadvantages of hydrogen power as opposed to hydrogen fuel, also what is the equation for hydrogen feul? I do not understand your first question. Hydrogen power REQUIRES hydrogen fuel. Hydrogen fuel is H2; ...
March 3, 2007 by ana

Chemistry
Can you tell me if i did these right?? Lewis Dot Structure A. BrF = 5 dots around Br-F with 5 dots around it B. PBr3 = ? I dont know how to do because of the 3 C. NOF= 3 dots around N 2 dots around O and 5 dots around F N-O-F D. CO = 3 dots around C double bond between O and 4...
December 3, 2007 by Lauren

chemistry/physics
i need to determine how many protons, neutrons, and electrons are in these but they arent just straight elements tehy are singly ionized hydrogen (positive) doubly ionized hydrogen(positive) and singly ionized oxygen (negative) these are my answers, respectively 1. one proton ...
September 13, 2009 by Andre

Chemistry
Select the true statements regarding the resonance structures of formate. HCO2 Check all that apply: Each oxygen atom has a double bond 50% of the time. The actual structure of formate is an average of the two resonance forms. Each carbon-oyxgen bond is somewhere between a ...
November 11, 2012 by Anonymous

Science
1. Which layer of the sun's atmosphere are you looking at when you look at an image of a sun? A) Photosphere B) Chromosphere C) Corona D) Prominence 2. What materials could have been found in a giant cloud that formed the solar system? A- hydrogen and helium B- hydrogen and ...
February 13, 2015 by Katie

Chemistry
I have to make a game based on the periodic table Here are the standards we could put in the game: Students know how to relate the position of an element in the periodic table for it's atomic number and mass Students know how to use the periodic table to ID, metals, semi-...
March 6, 2008 by johnny

Chemistry
I posted this question on Thursday April 12 and received some help..but need more.. thanks Use the following information to identify element A and come pound B, then answer questions a and b. An empty glass container has a mass of 658.572 g. It has a mass of 659.452 g after it...
April 16, 2007 by Julia

Microbio
I have a hard time with this finding the concept for the below: plz help How and in what way does the input of organic matter, such as sewage, effect the O2 content of a river or stream? A pond or lake? Does the organic matter get digested by bacteria, microbes et al? Do they ...
December 5, 2006 by Josh

chemistry
if one can find the ratio of the number of moles of the elements in a compound to one another, one can find the formula of the compound. in certain compound of copper and oxygen, Cux Oy, we find that a sample weighing 0.5424g contains 0.4831g Cu. a. How many moles of Cu are in...
June 23, 2010 by Ana

Chemistry
Where Can i find drawing of the electron dot structure of the following atoms. Argon,Calcium,Iodine www.webelements.com will give you the electron configuration. Scroll down the menu on the left side. The electron dot structure is done this way: Write the symbol for the ...
November 11, 2006 by Bryan

chemistry(oxidation)
ok,I really dont understand the whole oxidation numbers thing my question is state the oxidation number for nitrogen in the following NH3= -3 NO2-1= -1 N2= 0 NO2Cl= 5 N2H4 -2 am I correct? NH3= -3 NO2-1= -1 No, oxygen is -2, so N is +3 N2= 0 NO2Cl= 5 N2H4 -2 http://www....
May 17, 2007 by mike

plz help science
1. Which layer of the sun's atmosphere are you looking at when you look at an image of a sun? A) Photosphere B) Chromosphere C) Corona D) Prominence 2. What materials could have been found in a giant cloud that formed the solar system? A- hydrogen and helium B- hydrogen and ...
April 8, 2015 by bmx

Chemistry
These are the answers I got for the following problems - am I right? 1) How many grams of water, H2O, and propene, C3H6, can be formed from the reaction of 6.0 g of 2-propanol, C3H8O? C3H8O ----> C3H6 + H2O 1.8g H2O and 4.2g C3H6 2) How many moles of water, H2O, can be ...
November 29, 2009 by Mary

AP Chem
Use the following information to identify element A and compound B, then answer questions a and b. I'm so stuck on this problem and don't know where to begin. I need to have this problem done by Wednesday. PLEASE HELP!!! An empty glass container has a mass of 658.572 g. It has...
January 21, 2008 by John

Science Easy 2 Points!
Which of the following best explains why it is nessecary for the body to eliminate waste? a) to allow the body to maintain a certain size b) to keep the body's internal enviroment in balance c) to make room for nutrients coming in d) to reduce unpleasent odors What happens to ...
December 12, 2013 by Billabong

Chemistry
According to the ideal gas law a 9.03 sample of oxygen gas in a 0.8112 container at 499k should exert a pressure of 456atm. By what % does the pressure calculated using van der waals equation differ from the ideal pressure? For O2 gas a=1.36 L^2atm/mol2 and b=3.18e-2 Hint: %...
January 14, 2012 by Hannah

chem
Can someone help me with these please? 1) Use water as an example to contrast the properties of a compound with the elements from which it is composed. 2) If you tried to breath carbon dioxide, you would suffocate. Why, then, is carbon dioxide essential to all life on Earth? ...
January 11, 2007 by June

sience plz hep
1. Which layer of the sun's atmosphere are you looking at when you look at an image of a sun? A) Photosphere B) Chromosphere C) Corona D) Prominence 2. What materials could have been found in a giant cloud that formed the solar system? A- hydrogen and helium B- hydrogen and ...
April 7, 2015 by bmx

Science (Chemistry)
I did not understand the lesson today in my Chemistry I honors class. We went over the Law of Conservation of Mass for roughly 15 minutes and he gave us this worksheet. Could someone please display how to do this, I'll pull a problem from the worksheet. When 9.56g of Copper ...
October 7, 2009 by Michael Glass

PHYSICS
When a conducting sphere is charged positively, initially the charge is deposited on the left side. However, due to the sphere's conducting nature, the charge spreads uniformly throughout the surface to the sphere. Charge is uniformly distributed because: A. charged atoms at ...
April 8, 2009 by sophie

CHEM
I was just wondering if someone would be able to critique my answers for the following Chem questions? they range from pretty basic to a bit more... 2)which of the following is the definition of the value of Avogadro's constant: b) the # of Carbon atoms in exactly 12g of ...
October 21, 2007 by K

General Chemistry
Balance the following redox reaction in acidic and basic solutions: Fe(OH)2(s) + O2(g) --> Fe(OH)3(s) These are the steps my instructor gave us to balance redox reactions: 1. Divide into 1/2 rxns (reduction & oxidation) 2. Balance atoms other than H & O 3. Balance O with ...
April 3, 2013 by Emily

Chemistry
The complete combustion of 0.100 mol of CH4 in oxygen in a bomb calorimeter caused the water of the calorimeter to rise in temperature from 25.00 degrees Celsius to 37.70 degrees Celsius. Suppose that the combustion of the 0.1 mol of CH4 was instead run at constant pressure (1...
February 6, 2009 by HELP!!!

Chemistry
Consider a fuel cell that uses the reaction of ethanol with oxygen to produce electricity, CH3CH20H(l)+ 3O2(g)---> 2CO2(g)+3H2O Use thermodynamic data to determine the value of E°cell for this cell at 25 °C. I don't really know where to start. I got the standard G for ...
May 5, 2014 by Sophie

honors chemistry- isotopes...
can scientists actually measure the mass and relative abundance of isotopes of an element by counting each particle and measuring their masses? [ i think no because it would be too small ] if not, how could a scientist measure the mass and relative abundance of isotopes of an ...
October 31, 2006 by guitarking4000

Chemistry
The reaction for the decomposition of dinitrogen monoxide gas to form an oxygen radical is: N2O(g)==>N2(g)+O(g) . If the activation energy is 250 kJ/mol and the frequency factor is 8.0 x 1011 s-1, what is the rate constant for the first-order reaction at 1000 K? k = A * exp...
March 1, 2010 by gaby

science
Where does the exchange of carbon dioxide and oxygen with the blood occur the bronchi bronchiole alveolar ducts alveolar sacs It seems that you are asking different questions under different names. You can ask more than one question on a post. Think of it as transportation. ...
May 19, 2007 by dimples

chemistry
Based on the mass of O2 produced can you calculate the gram molecular weight? Chem lab on oxygen production 10g KClO3 reacts with heat to produce 2KCl(s)+3O2.What is the mass produced? 10g/122.6=0.0816 mole of KClO3 0.00816x3moleO2/2moleKClO3=0.1224 moleO2 0.1224 molex32g O2/...
October 18, 2010 by michelle

science ms sue plz help
1. Which layer of the sun's atmosphere are you looking at when you look at an image of a sun? A) Photosphere B) Chromosphere C) Corona D) Prominence 2. What materials could have been found in a giant cloud that formed the solar system? A- hydrogen and helium B- hydrogen and ...
April 10, 2015 by need help plz

AP CHEMISTRY
A)In a chemical reaction two gases combine to form a solid. What do you expect for the sign of ΔS? B) For which of the following processes does the entropy of the system increase? (Select all that apply.) -> alignment of iron filings in a magnetic field -> the ...
March 19, 2012 by HELP PLEASE

Plz, Ms.Sue/anyone check my answers?
1. Which of the following best explains why it is necessary for the body to eliminate waste? to allow the body to maintain a certain size to keep the body’s internal environment in balance to make room for nutrients coming in *** to reduce unpleasant odors 2. What happens to ...
May 13, 2014 by Princess Anna

chemistry
1. Ceramic material made by the sol-gel process involve the reaction of a. water and acids. b. ethanol and water. c. water and metal oxides. d. acids and metal alkoxides. e. water and metal alkoxides. my ans. c 2. The step in the sol-gel process that forms oxygen bridges while...
December 2, 2012 by 657

chemistry
sulfur trioxide gas dissociates into sulfer dioxide gas and oxygen gas at 1250 degrees C. In an experiment, 3.6 moles of sulfur trioxide were placed into an evacuated 3.0-L flask. THe concentration of sulfur dioxide gas measured at equilibrium was found to be 0.20 M. What is ...
April 29, 2007 by alexa

Chemistry
can anyone check and see if i balanced the equation for the combustion of benzene correctly, thank you. C6H6 + O2 --> CO2 + H2O Answer: C6H6 + 15O2 --> 6CO2 + 3H2O It doesn't look right to me; however, you can check ALL balanced(?) equations and know when you are right ...
August 7, 2007 by Anonymous

Chem
Butane, C4H10, is widely used as a fuel for disposable lighters. When one mole of butane is burned in oxygen, carbon dioxide and steam are formed and 2658 kJ of heat is evolved. a) Write the thermochemical equation for the reaction. First I wrote the chemical equation for the ...
February 1, 2007 by Chris

chemistry
Compound B is acetylcholine, a neurotransmitter found in the human body. It binds to receptors, leading to nerve stimulation. (in case this post does not show correct, two of the CH3 should be above and below the N^+ , AND THE O should be above the C) COMPOUND B CH3 O | | H3C...
January 29, 2009 by trigger

chem
If one pound (454g) of hexane combusts with 185 grams of oxygen which reactant is the limiting reactant and how many grams of carbon dioxide are produced? My work: 454 g C6H14 * 1 mol C6H14/86.18 g C6H14 * 6 mol CO2/ 1 mol C6H14 * 44 g C02/ 1 mol CO2= 1390.7 g/ CO2 185 g O2 * ...
April 1, 2015 by Sarah

Environmental Science
I need a little help on these, i've posted them a few times but i don't get any answers. 29. A common feature of thermal pollution and artificial eutrophication is that they both a. have sources that are difficult to identify and control b. cause large mats of algae to bloom ...
February 8, 2010 by y912f

chem
How would i found out the freezing point of a solution which has 0.05mol of acetic acid dissolved into 125g of benzene? Benzene melts at 5.5C and has a constant of 5.1C/m. The acid forms a dimer (what is this and how does it affect the calculations?) A dimer is a molecule from...
August 7, 2007 by Chris

kim
a gaseous hydrocarbon reacts completely with oxygen gas to form carbon dioxide and water vapor. given the following data, determine (delta)HoF for hydrocarbon: (delta)Horxn=-2044.5kj/mol hydrocarbon (delta)HoF CO2= -393.5kj/mol (delta)HoF H2O = -242kj/mol denstity of CO2 and ...
April 20, 2008 by chemistry

Chemistry
I am having so much trouble understanding how to classify reactions as precipitation, acid base, or oxidation reduction. In one example in particular, it reads Iron II oxide reacts with oxygen and water to yield Iron III hydroxide. I wrote out the equation as: FeO(aq)+O2(g)+...
April 21, 2015 by Tracey

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