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March 28, 2017

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Number of results: 6,956

chemistry 30
Catalytic converters in automobiles are used a. only to burn uncombusted gasoline b. only to convert carbon monoxide to carbon dioxide c. only to convert nitrogen oxides to nitrogen and oxygen d. all of the above
December 30, 2011 by Tucker

Chemistry
Sorry to bother again. I'm stuck in these two problems as well. 1. A 27.0 g smaple of an unknown hydrocarbon was burned in excess oxygen to form 88.0 g of carbon dioxide and 27.0 g of water. What iss a possible molecular formula of the hydrocarbon? 2. A sample of CaCO3 was ...
September 9, 2007 by Anonymous

chemistry
Match the correct mole ratio to the substances in the reactions below. carbon monoxide to iron in the reaction: Fe2O3 + CO ==> Fe + CO2 water to manganeese(II) chloride in the reaction: HCl + MnO2 ==> H2O + MnCl2 + Cl2 sodium to oxygen in the reaction: Na + O2 ==> ...
February 29, 2008 by joshua

science --- check my answers!
help pls asap!!!!! check my answers!!! 4.) A certain object has a volume of 25.0 mL and a mass of 100g. What is the density of the object? a)0.250 g/mL b) 4.00/mL*** c)125 g/mL d) 2500 g/mL 5.)Which of the following is a chemical property of aluminum? a)The melting point of ...
January 30, 2014 by TTR+S<3

biology
which of the following statements are true there are 2 polar covalent bonds in water there are 3 ionic bonds in water there is 1 ionic and 1 covalent bond in water electrons are less attracted to oxygen than hydrogen
August 28, 2009 by brenda

CHEM !(MOLE) PLZ HELP!
1.How many grams are in one mole silicon? 2. how many moles are in 128 grams of oxygen gas (O2)? 3.How many molecules are in 2 moles of AIO? 4.How many moles are in 18.06 x 10 to the 23 power? 5. how many moles are in 100 grams of CH4?
December 6, 2012 by tyneisha

chem
There are several exceptions to the octet rule found along the transition and rare earth metal sections. These exceptions are tied to the observed phenomenon that atoms are more stable if orbital systems are either whole or half filled. In other words, the electron ...
November 19, 2006 by Alexa

science
I know that every element has only a certain set of allowed energy states & that the exact energy of these states depends upon the number of electrons, but why is the colour of the light emitted by an element (in GASEOUS STATE) characteristic of the element? The color of light...
February 7, 2007 by duncan

geology(this correct)
Where do metamorphic rocks originate? How are they formed? What are the two categories of metamorphic rocks? What are the distinguishing characteristics between the two categories of rocks? Metamorphic gets their name from change which is called "meta" and "morph" the proper ...
June 12, 2009 by scooby9132002

Nuclear 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 3, 2008 by Gabe

Chemistry
Full question: An alcohol of molecular formula C4H10O2 contains two OH groups and has an unbranched carbon atom chain. On reaction with excess hot potassium permanganate this alcohol is converted into a compound of molecular C4H6O4 To which carbon atoms in the chain of the ...
August 22, 2014 by Ariana

chemistry
N2 + 2 O2 ---> 2 NO2. Suppose 31.25 g of N and 44.0 g of oxygen react. A. Calculate the mass of Nitrogen dioxide formed. B. Which reactant is the limiting reactant? C. Calculate the mass of the excess reactant left after the reaction. D. Find the % yield if 52.3 g of NO2 is...
October 30, 2013 by Stacy

Chemistry
30 cubic-centimetre hydrocarbon requires 90 cubic-centimetre of oxygen for complete combustion and 60 cubic-centimetre of carbondioxide is formed .What is the formula of hydrocarbon?
May 14, 2012 by NItesh Kumar

physics
The higher the energy level occupied by an electron in the hydrogen atom, the larger the atom. The diameter of the atom is proportional to n2, where n = 1 labels the lowest, or "ground" state, n = 2 is the second state, n = 3 is the third state, and so on. If the atom's ...
August 4, 2011 by stacy

Math
Bob was given and exercise prescription for 3-5 METS for his home exercise program. He is currently walking, and at the fitness center using a treadmill, walking 3.2 mph up a3% incline. Bob weighs 70kg. is Bob exercising in his prescribed zone? 1 MET = 3.5 mL of oxygen/kg of ...
November 22, 2010 by kaden

Chemistry
A sample of ethanol, C2H5OH, weighing 2.84 g was burned in an excess of oxygen in a bomb calorimeter. The temperature of the calorimeter rose from 25.00°C to 33.73°C. If the heat capacity of the calorimeter and contents was 9.63 kJ/°C, what is the value of q for burning 1....
June 7, 2011 by Lance

chemistry
A sample containing 5.20g O2 gas has a volume of 19.0L, pressure and temperature remain constant, Oxygen is released until the volume is 7.00L how many moles of O2 are removed I know i convert 5.20g to moles which give me 0.1625 moles of O2 and i use the P=nRT/V formula but i ...
July 24, 2011 by SHARON

Chemistry
The flame in a torch used to cut metal is produced by burning acetylene(C2H2) in pure oxygen. Assuming the combustion of 1 mole of acetylene releases 1251kj of heat, what mass of acetylene is needed to cut through a piece of steel if the process requires 36.658 x 10^4 kj of heat?
November 8, 2012 by Brittany

Physics
If two protons and two neutrons are removed from the nucleus of an oxygen-16 atom, a nucleus of which element remains? Carbon 12 will be the answer, but i need to understand the answer. I requested help from a friend but was given the answer and not explained. I am having a ...
August 28, 2013 by Sean

Social Studies
The depletion of the world’s rain forests contributes to all of the following except a. a decrease in oxygen that is released into the atmosphere. b. an increase in the temperature. c. a decrease in the amount of carbon dioxide that is released in the atmosphere.*** d. a ...
January 11, 2016 by Kaai97

Chemistry
Consider a sample of helium and a sample of neon, both at 30ºC and 1.5atm. Both samples have a volume of 5.0 liters. Which statement concerning these samples is not true? a- each weighs the same amount b- each has the same # of atoms of gas c- the density of the neon is ...
November 6, 2009 by John S.

Chem answer check
Does this look correct? Thx! Write the balanced equation for the reaction between solid copper and silver nitrate, that produces solid silver and copper(II) nitrate in solution. Include your experimentally determined mole ratios for the copper and silver atoms as coefficients...
February 15, 2010 by Kelsey

Chemistry (urgent)
Hydrolysis of a compound A, C7H6cl2 was carried out by refluxing with excess potassium hydroxide solution. the resulting solution was acidified with dilute HNO3 acid and excess silver nitrate was added to precipitate the chloride ions as silver chloride. 0.718g of silver ...
October 23, 2014 by Kris

college math
Find the distance of the shotcut and the distance of the long way for two locations. find the number of seconds saved ( 2.1 and 5.8) Approximate the are of the affected region (24 and 248 Sq Ft). find the average amount of oxgen saved per second saved (10.8 and 110.6 KG of ...
March 1, 2011 by JC

chemistry
A mixture of ammonia and oxygen is prepared by combining 0.330 L of NH3 (measured at 0.710 atm and 22°C) with 0.200 L of O2 (measured at 0.740 atm and 51°C). How many milliliters of N2 (measured at 0.740 atm and 100. °C) could be formed if the following reaction occurs? ...
December 3, 2014 by Libby

Chemistry help (DrBob222)
propane (c3h8) is burned in oxygen to produce carbon dioxide and water. The heat of combustion of propane is -2012 kJ/mole. How much heat is given off when 3.0 mol C3H8 are react with 10.0 mol O2? Thanks, and please if possible show all steps!
October 15, 2013 by K

chemistry
What volume of air is needed to burn an entire 60-L (approximately 16-gal) tank of gasoline? Assume that the gasoline is pure octane, C8H18. Hint: air is 20% oxygen by volume, 1 mol of a gas occupies about 25 L at room temperature, and the density of octane is 0.70 g/cm3.
October 9, 2016 by Joe Smith

solid chem
A p-n junction is obtained at a depth of 3 x 10-3 cm below the surface by diffusion of antimony (Sb) into p-type germanium. What is the donor concentration in the bulk germanium if the diffusion is carried out for three hours at 790 C? Express your answer in number of donor ...
November 15, 2013 by solid chem

solid chem
A p-n junction is obtained at a depth of 3 x 10-3 cm below the surface by diffusion of antimony (Sb) into p-type germanium. What is the donor concentration in the bulk germanium if the diffusion is carried out for three hours at 790 C? Express your answer in number of donor ...
November 15, 2013 by solid chem

CHEMISTRY HELP !!!! CHECK !!!
Al3+ is reduced to Al(s) at an electrode. If a current of 2.75 ampere is passed for 36 hours, what mass of aluminum is deposited at the electrode? Assume 100% current efficiency. a. 9.2 x 10–3 g b. 3.3 x 101 g c. 9.9 x 101 g d. 1.0 x 102 g e. 3.0 x 102 g Answer 2.75 A for 36...
May 8, 2014 by YULCHANG

Chemistry 1201
An unknown compound contains only carbon, hydrogen, and oxygen (C?H?O?). Combustion of 6.50 of this compound produced 9.53 g of carbon dioxide and 3.90 g of water. 1) How many moles of Carbon? 2) How many moles of Hydrogen?
March 28, 2012 by Dylan

Chemistry
If sulfur dioxide and oxygen can be made into sulfur troxide, what is the reverse reaction? 2SO3-->2SO2+O2*** SO3+O2-->SO5 2SO2+O2-->2SO3 SO3+2SO3-->3S+4O2
May 4, 2016 by Jordan

solid chemestry
A membrane is to be manufactured to the following specifications. The leak rate of hydrogen is not to exceed 10-3 mol-cm-2h-1 at 700 C when the concentration of hydrogen is maintained at 1.5 x 1019 atoms/cm3 on one side of the membrane and effectively zero on the other side. ...
November 15, 2013 by Anonymous

solid chemestry
A membrane is to be manufactured to the following specifications. The leak rate of hydrogen is not to exceed 10-3 mol-cm-2h-1 at 700 C when the concentration of hydrogen is maintained at 1.5 x 1019 atoms/cm3 on one side of the membrane and effectively zero on the other side. ...
November 15, 2013 by Anonymous

Chemistry
Consider the reaction of magnesium metal with hydochloric acid to produce magnesium chloride and hydrogen gas. If 3.85 mol Mg and 3.85 mol of HCl are reacted, how many mol of oxygen are left over? I balanced the equation and got Mg(OH)2+2HCl=MgCl2+2H2O. Can you please walk me ...
March 20, 2012 by Jessica

Chemistry
A 1.250 g sample of copper wire was heated in air and reacted with oxygen to give 1.565 g of copper oxide product. Calculate the empirical formula of the copper oxide. Please help I'm lost. I need step by step Please and thank you
September 21, 2011 by Monique

Chemistry
Oxygen gas can be generated by heating KClO3 in the presence of some MnO2. 2KClO3 → 2KCl + 3O2 If all the KClO3 in a mixture containing 1.58 g KClO3 and 0.30 g MnO2 is decomposed, how many liters of O2 gas will be generated at T = 25.0°C and P = 760.6 torr?
October 27, 2013 by Billy

chemistry
Suppose you designed an experiment in which you burned a known quantity of magnesium in air. You used the product to determine how many moles of oxygen would react with the known number of moles of magnesium. Why would burning magnesium in air cause a source of error for this ...
January 25, 2015 by Morgan

CHEMISTRY
Oxygen gas can be generated by heating KClO3 in the presence of some MnO2. 2KClO3 → 2KCl + 3O2 If all the KClO3 in a mixture containing 1.64 g KClO3 and 0.20 g MnO2 is decomposed, how many liters of O2 gas will be generated at T = 23.0°C and P = 767.9 torr?
November 6, 2015 by Anonymous

AP Chemistry
Suppose you designed an experiment in which you burned a known quantity of magnesium in air. You used the product to determine how many moles of oxygen would react with the known number of moles of magnesium. Why would burning magnesium in air cause a source of error for this ...
July 5, 2016 by Jessica AP Chemistry

physics
The mass of a carbon atom is 2 x 10 ^ -26. What is the kinetic energy of a carbon atom moving with a speed of 500 m/s? I got 2.5 x 10^-21 which is correct. The second question states: Two carbon atoms are joined by a spring-like carbon-carbon bond. The potential energy stored ...
November 30, 2009 by Julia

ENGLISH (ESL)
A nurse was working in ER, during her shift, she see a please need proof reading . patient who is having fever of 101 degree F. The patient also has open wound on his left leg, the wound is red, painful, swollen, and foul-smelling pus is showing signs of infection. The patient...
September 14, 2013 by shan

Chemistry quick question
For the following write the chemical formulas for the reactants and predict the most likely reaction type , then write balanced equations for each: A.) magnesium chloride is heated b.) silver nitrate is reacted with sodium sulfide c.) methanol is burned in the presence of ...
April 2, 2014 by Anonymous

Chemistry
A 10.0 gram sample of a mixture of CH4 and C2H4 reacts with oxygen at 25°C and 1 atm to product carbon dioxide gas and liquid water. If the reaction produces 520 kJ of heat, what is the mass percentage of CH4 in the mixture? I am all out of tries on the homework, but I would ...
October 27, 2014 by Jane

SCIENCE
CAN SOMEONE PLEASE HELP ME AND TELL ME IF IM RIGHT OR WHAT ????!!!!!!!!! Explain which statement is correct: energy is lost when water is boiled or the energy used to boil water is present, but it is no longer in a usable form unless you use work or heat to make it usable. i ...
April 28, 2009 by bobbi

science
CAN SOMEONE PLEASE HELP ME AND TELL ME IF IM RIGHT Explain which statement is correct: energy is lost when water is boiled or the energy used to boil water is present, but it is no longer in a usable form unless you use work or heat to make it usable. i think that the 2nd one ...
April 28, 2009 by bobbi

chemistry
An experiment is set up in which a copper surface is irradiated with high-intensity photons with a wavelength of 15.0nm. Electrons ejected from the surface are found to have a velocity of .548% of c. What is the binding energy of copper's most weakly bound electrons? What is ...
June 28, 2012 by Anonymous

science
how do i balance this equation: sodium hydroxide reacting with sulfurous acid [1 mol sulfurous acid reacts with 2 moles hydroxide ion] my hydrogens aren't balancing right 2 NaOH + H2SO3 -> Na2SO3 + 2 H2O ah thx, i accidently wrote H3O Why are oxygen tanks and spacesuits ...
October 19, 2006 by Dan

chemistry PLEASE HELPPPP
10.0 grams of carbon dioxide and 20.0 grams of oxygen are mixed in a 50.0 L container at 30.0 degrees celcius. What is the pressure of this mixture in mm Hg? I defined my variables. so i had Mass=30.0g Volume=50.0L Temperature=303 Kelvin pressure=x. then i used PV*GFM=mRT. (x...
March 18, 2008 by Miley

Chemistry
8.40 grams of Hydrogen gas reacts with 48.2 grams of Oxygen gas. Give the mass of the water vapor produced and the mass of the excess reactant left over. Can somebody please explain stoichiometry to me? I've failed the test and the retest. I'm usually able to balance the ...
November 29, 2010 by Anna

anatomy
If the pleural space lost its negative pressure which of the following would be true? A.Inspiation would be more difficult B.Expiration would be more difficult C.Sufactant wouldnt be needed D. Exchange of oxygen and carbon dioxide would improve I think it is would be D but not...
September 27, 2008 by uknown

biology
Explain how respiration and the circulatory system work together when an individual is exercising. Does tissue need oxygen at a higher rate? Does tissue need to void CO2 at a higher rate? Does the heart pulse speed up? Does the breathing rate increase?
June 7, 2007 by Gabrielle

Science help,Anyone?
1. Why is it rare for the soft parts of an organism to become a fossil? The soft parts take a long time to decay. The soft parts can be eaten by other animals. The soft parts cannot be buried in sediment. The soft parts form petrified fossils. 2. Which of the following terms ...
December 10, 2013 by Princess Anna

Chemistry
A sample of oxygen is collected in a 387 mL container over water at 15◦C, and the barom- eter reads 738 torr. What volume would the dry gas occupy at 781 torr and 15◦C? Water’s partial pressure at 15◦C is 12.8 torr. Answer in units of mL
November 20, 2012 by Caitlin

To: Bobpursely
You helped me with my observations yesterday, but I need help with my questions as well. I tried to answer as many as I could by myself, but I'm having difficulties understanding some. Pointing me towards the right direction would be helpful, thanks. Questions: Which changes ...
April 7, 2010 by Sara

solid chemestry
A p-n junction is obtained at a depth of 3 x 10-3 cm below the surface by diffusion of antimony (Sb) into p-type germanium. What is the donor concentration in the bulk germanium if the diffusion is carried out for three hours at 790 C? Express your answer in number of donor ...
November 15, 2013 by Anonymous

chem help
a scuba diver breathing normal air descends 100m of depth, where the total pressure is 11 atm. What is the partial pressure of oxygen that the diver experiences at this depth? Can someone help out on this question? Make a ratio: 11atm/1atm= P/partial pressureO2 at surface ...
March 19, 2007 by david

chemistry
In the formation of smog, nitrogen and oxygen gas react to form nitrogen dioxide: N2(g)+2O2(g)→2NO2(g)How many grams of NO2 will be produced when 2.1L of nitrogen at 840mmHg and 28∘C are completely reacted? I know that you use the equation n=PV/RT to get the number...
October 26, 2013 by ellie

Science
the active ingredient in the alergy medication claritin contain carbon,hydrogen,chloride,nitrogen,and oxygen its molecules formula is C22H23ClN2O2.the standard adult gosage utizies 1.572*10^19 molecules of the spicies determine the mass gosage of the active ingridient in the ...
February 2, 2016 by Kriatian ferrer

Chemistry
A compound of Tin Sulfate is decomposed in the lab to give 1.91g of Tin, 1.03 grams of Sulfur, and 2.06g Oxygen. Determine if this is a compound of Tin(II) Sulfate or Tin(IV) Sulfate.
February 16, 2013 by Dylan

AP Chemistry
Textrodotoxin is a toxic chemical found in fugu pufferish, a popular but rare delicacy in Japan. The compound has a LD50 (the amount of substance that is lethal to 50% of a population of iron (iii) hydroxide. Textrodotoxin is 41.38% carbon by mass, 13.16% nitrogen by mass, and...
October 15, 2009 by Rose23

chemistry
A 0.016076-mol sample of an organic compound was burned in oxygen in a bomb calorimeter. The temperature of the calorimeter increased from 23.7oC to 24.5oC. If the heat capacity of the calorimeter is 4.98 kJ (oC)-1, then what is the constant volume heat of combustion of this ...
March 1, 2014 by abby

chemistry
A 0.016076-mol sample of an organic compound was burned in oxygen in a bomb calorimeter. The temperature of the calorimeter increased from 23.7oC to 24.5oC. If the heat capacity of the calorimeter is 4.98 kJ (oC)-1, then what is the constant volume heat of combustion of this ...
March 5, 2014 by abby

Flotation is widely used for processing all kinds
In most instances, flotation is used for processing sulfide auriferous ores whose flotability is quite high and the effect is most notable. By flotation, the gold can be enriched to sulfide ore concentrate as much as possible and the abandoned tailings can be got. The ore ...
July 22, 2012 by jiandan

Chemistry
Choose an alkane that is 6 to 10 carbon atoms in length. List the alkane's name and the other isomers you can properly draw and name. For example: Decane / isomer 2 methyl-Nonane. Do not guess. Draw out on paper then name for best results. Include the drawing of the alkane and...
May 27, 2016 by Anonymous

Physics
The masses of 1 mole of various gases are as follows: hydrogen about 2 grams, helium about 4 grams, nitrogen about 28 grams, oxygen about 32 grams and carbon dioxide about 44 grams. On the average how fast does a molecule of each gas move at 333 Celsius?
April 6, 2010 by Benny

physics
The masses of 1 mole of various gases are as follows: hydrogen about 2 grams, helium about 4 grams, nitrogen about 28 grams, oxygen about 32 grams and carbon dioxide about 44 grams. On the average how fast does a molecule of each gas move at 333 Celsius?
April 6, 2010 by Plaster

Chemistry
Can you please someone check my answer for me? I don't know how to start thses answer. Chemistry is not my things. Please give me answers. :( a)Determine the number of grams in 0.750 moles of the compound Iron(II)phosphate: Fe3(PO4)2. Answer: ? b)How many atoms of iron are in ...
March 31, 2010 by Anonymous

Jefferson
Nitric acid and zinc react to form zinc nitrate, ammonium nitrate, and water. 4Zn(s) + 10HNO3(aq)→ 4Zn(NO3)2(aq) + NH4NO3(aq) + 3H2O(l) A. How many atoms of zinc react with 1.49g HNO3? B. Calculate the number of grams of zinc that must react with an excess of HNO3 to ...
January 7, 2013 by Gloria

chemistry
Nitric acid and zinc react to form zinc nitrate, ammonium nitrate, and water. 4Zn(s) + 10HNO3(aq) → 4Zn(NO3)2(aq) + NH4NO3(aq) + 3H2O(l) A. How many atoms of zinc react with 1.49g HNO3? B. Calculate the number of grams of zinc that must react with an excess of HNO3 to ...
January 7, 2013 by Anonymous

Chemistry
which of the following statements are true? a) For an acid H-O-A : the greater the electronegativity of A, the weaker the acid HA b) For an acid H-A : the weaker the H-A bond, the stronger the acid H-A c) HF is a stronger acid than HCl d) HClO4 is a weaker acid than HClO2 e) ...
October 15, 2009 by Anonymous

Science: Chemistry
1. The element gold, Au, has a face-centered cubic structure. (Density - 19.3 g/cm^3) (a) What are the # of gold atoms in 1 unit cell? (b) What are the # of unit cells in 1 mol? (c) What is the volume of 1 mol gold unit cells? (d) What is the volume of 1 unit cell? (e) what is...
November 8, 2014 by Supriya

Gases - van der waals
It turns out that the van der Waals constant b equals four times the total volume actually occupied by the molecules of a mole of gas. Using this figure, calculate the fraction of volume in a container actually ocupied by Ar atoms (a) at STP, (b) at 100 atm pressure and 0 ...
December 7, 2006 by Jenn

Math/Chemistry
the atomic mass of an element is the mass, in grams, of one mole (mol), or 6.02 * 10^23. A.) How many atoms are there in 3.5 mol od carbon? B.) If you know that 3.5 mol of carbon weighs 42 grams, what is the atomic mass? C.)Using you answer from (B), find the approximate mass ...
August 22, 2011 by Chaney

chemistry
Which of the following is a feature of an aromatic compound? Which of the following is a feature of an aromatic compound? It has a strong aroma. Its formula contains only six carbon atoms. It contains a benzene ring. It contains only carbon-carbon double bonds.
November 7, 2014 by Shatoya

science
when can the plant start to make its own food? A plant always makes its own food. Ever since it existed it made its own food through photosynthesis. The leaves take in the sunlight and form it into food. It also releases oxygen.
February 27, 2007 by christina

chemistry
Consider the following reaction: 2 NO(g) + O2(g) ---> 2 NO2(g) + energy if the number of moles of oxygen is increased to two moles, the a. reaction speeds up b. reaction slows down c. temperature increases d. temperature decreases I'm not really sure what the answer to this...
February 21, 2012 by Aria

Chemistry-Explanation Please
Oxygen gas can be generated by heating KClO3 in the presence of some MnO2. 2KClO3 → 2KCl + 3O2 If all the KClO3 in a mixture containing 1.00 g KClO3 and 0.25 g MnO2 is decomposed, how many liters of O2 gas will be generated at T = 24.0°C and P = 755.6 torr?
November 1, 2012 by Kwame

chemistry
When a 6.79-g mixture of methane, CH4, and ethane, C2H6, is burned in oxygen at constant pressure, 369 kJ of heat is liberated. What is the percentage by mass of CH4 in the mixture? The standard enthalpies of combustion for CH4 and C2H6 are -890.3 kJ mol-1 and -1569.7 kJ mol-1...
March 1, 2014 by abby

Chemistry+need help checking work
Using aervage atmoic masses for each of the following elements, calculate the mass, in amu (grams) A. 635 atoms of hydrogen ---> 1 mole of H = 1.01g = 6.022 x 10^23 atom 635 atom of H 1.01g/6.022 x 10^23 atom I got 1.06 x 10^-21 amu. I got that answer buying the "E" button ...
January 7, 2009 by Chopsticks

Chemistry
Hi Im reposting incase my original post doesn't get read. Please see bottom for additional info that I need help getting verified. Many thanks Hi Please help verify my answer to the following question: 0.500g of pure phosphorous was burned in excess pure oxygen to give a ...
October 16, 2011 by Helpme

HS Science
I have 4 questions 1 What is the equation for the acid ionization constant of HI? 2 Give the oxidation numbers of all atoms in NaMnO4 3 An atom changes its oxidation number from -2 to -5. Is it oxidized or reduced? How many electrons did it take to do this? 4 An atom changes ...
June 30, 2011 by Ashley

Chemistry
1. The eleent gold, Au, has a face-centered cubic structure. (Density - 19.3 g/cm^3) (a) What are the # of gold atoms in 1 unit cell? (b) What are the # of unit cells in 1 mol? (c) What is the volume of 1 mol gold unit cells? (d) What is the volume of 1 unit cell? (e) what is ...
November 8, 2014 by Supriya

chemistry
A sample contains Hydrogen atom ,He+ ion, Li2+, & Be3+ ion. In H atom electron is present in 8th orbit, in He2+ e- is present in 6th orbit, Li2+ in 5th orbit& in Be3+ electron is present in 4th orbit. All the atoms are de-excited to the ground state. Calculate the total no. of...
June 4, 2014 by Swapnil

Chemistry
A sample of iron weighing 15.0 g was heated with potassium chlorate (KClO3) in an evacuated container. The oxygen generated from the decomposition of KClO3 converted some of the Fe to Fe2O3. If the combined mass of Fe and Fe2O3 was 17.9g,calculate the mass of Fe2O3 formed and ...
August 22, 2013 by Francis

science
1.5173 g of organic iron compound containing FE , C ,H and O is burnt in oxygen gas produced 2.838 g OF carbon dioxide and 0.8122 g of water. In separate experiment to determine the mass % of iron, 0.3355 g of the compound yielded 0.0758 g iron (II) oxide. Determine the ...
June 28, 2016 by Nor

HelpMeLinda
Hello miss Linda I really appreciate you explaning the topic thankyou very much my question is Why does stone (concrete) strong under compression ? can you explain me this and Why is Steel strong under tension ? thank a mil Well, stone is not always stronger under compression...
June 7, 2007 by Jr. Smith Laren

chemestry
At 298.K and 1.00 atm, assume that 22 mL of NO gas reacts with 18 mL of oxygen gas and excess water to produce nitric acid according to the following equation: O (g) H O(l) 2 HNO (g) 2 3 2NO(g) + 2 + 2 ¾¾® 3 . If all of the nitric acid produced by this reaction is collected...
November 2, 2010 by lore

chemistry
If 1.70 liters of 0.670 M CuSO4 solution is electrolyzed by passing 4.70 amps through the solution for 3.00 hr using inert electrodes. (a) As electrolysis proceeds, how does the acidity of the solution change? (b) How many grams of Cu metal are formed at the cathode? (c) How ...
November 19, 2010 by Dana

science
bornite(Cu3FeS3)is copper ore used in the production of copper.when heated,the following reaction occurs.2CuFeS3(s)+7oxygen(g)=6Cu(s)+2FeO(s)+6SO2(g)..IF 3.88 metric tons of bornite is reacted with excess oxygen and the process has 75.6 percent yield of copper,what mass of ...
June 13, 2011 by mushibwe lameck c

Chemistry
A neutral molecule is identified as a tetrafluoride, XF4, where X is an unknown atom. If the molecule has a dipole moment of 0.63 D, can you give some possibilities for the identity of X? (Select all that apply.) sulfur nitrogen oxygen polonium phosphorus selenium tellurium ...
June 17, 2011 by Lance

chemistry
a typical alberta home heated with natural gas assume methane CH4 (g) consuems 2.00ML of natural gas during the month of December. What volume of oxygen at SATP is required to burn 2.00ML of methane measured at 0 degrees and 120 kPa? the answer is 2.62ML but i do not know how ...
March 23, 2012 by anita

chemistry
Use the molar mass of the following in order to calculate the number of moles from the given masses. Watch the significant figures a) 0.025 g of oxygen b)0.657 g og copper c) 0.7 g of chlorine I know how to calculate with finding the molar mass but not this way. thank you so ...
October 27, 2014 by MC

Chem: primitive cubic packing
Answer the following for a primitive cubic unit cell. For the type of packing answer, use letters (starting with A, then B, then C) without spaces and separated by hypens (-) to indicate the layers of solid present. type of packing =? type of holes =? # atoms / 1 unit cell = 1...
February 13, 2009 by Anonymous

Biology
Wine is made by mixing yeast with grapes and allowing the yeast cells to undergo fermentation. Sparkling wine is a type of wine that contains high levels of dissolved carbon dioxide. What is the source of the carbon atoms in the carbon dioxide found in sparkling wine? ethanol ...
February 1, 2016 by Steve

Check my Science questions?
1. Why is it rare for the soft parts of an organism to become a fossil? The soft parts take a long time to decay. The soft parts can be eaten by other animals. The soft parts cannot be buried in sediment. The soft parts form petrified fossils. 2. Which of the following terms ...
December 11, 2013 by Princess Anna

chem
A 75.0 L stainless steel container was charged with 3.00 atm of hydrogen gas and 4.00 atm of oxygen gas. A spark ignited the mixture, producing water. What is the pressure in the tank at 25°C? in atm What is the pressure in the tank at 125°C? in atm
November 17, 2007 by mel

chemistry
From the following combustion: 1-butanol + oxygen = carbon dioxide + water. How many grams of carbon dioxide and water are produced when 130.6 grams of 1-butanol is completely burned? Please help me! I have not a clue! Thanks so much!
November 28, 2009 by Turtle Lover

Biology
20. When the blood enters the gill filaments in a fish, its carbon dioxide content is ________ and oxygen content is _____ a. low;high b. low;low c. high;high d. high;low D? I'm not sure about this question... Thanks -MC
March 18, 2010 by mysterychicken

chem
A 4.91 g sample of aluminum completely reacts with oxygen to form 6.85 g of aluminum oxide. Use this data to calculate the mass percent composition of aluminum in aluminum oxide. i got 61.2% first and it was wrong. then i got 53.0% and it was wrong
November 11, 2010 by hannah

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