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October 26, 2014

Posts by Odesa


Total # Posts: 98

Chemistry
a) 11.13 b) 10.76
January 11, 2013

Chemistry
iv) Ti
January 11, 2013

Chemistry
a)Addition Polymerization b)14286 c) iii) isotactic
January 11, 2013

Chemistry
a) 2.9844 b)K2O = basic Al(OH)3 = amphoteric Si(OH)4 = acidic CaO = basic
January 11, 2013

Chemistry
a)vii:sp3d2 b)i:Slightly less than 90 c)4.13346*10^-7
January 11, 2013

Chemistry
a) 4.27 x 10^-6 b) 536.7
January 11, 2013

Chemistry
a) Higher T b) Thermoplastic c) 5520
December 18, 2012

Chemistry
a) stiff b) Addition polymerization c) 3.091×10^6 / 104.15 = 29678.34
December 18, 2012

chemistry
Thank you
December 18, 2012

chemistry
Thank you
December 17, 2012

chemistry
Thank you
December 17, 2012

Chemistry
Do you any idea to answer this question below, do give some input by providing data and how to with formula. A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.31 kg m-3. Under these conditions the total surface area of the balloon is 0.11 ...
December 15, 2012

Chemistry
Example:(remember to substitute with your data) Step 1: ξ= (0.5 * carbon concentration at the surface of the steel - carbon concentration at the surface of the steel)/ (carbon concentration in the steel before carburization - carbon concentration at the surface of the ...
December 15, 2012

Chemistry
Step 1: ξ= (0.5 * carbon concentration at the surface of the steel - carbon concentration at the surface of the steel)/ (carbon concentration in the steel before carburization - carbon concentration at the surface of the steel) (0.5* 8655.0 - 8655.0 )/ ( 299.0 - 8655.0...
December 15, 2012

chemistry
Step 1: ξ= (0.5 * carbon concentration at the surface of the steel - carbon concentration at the surface of the steel)/ (carbon concentration in the steel before carburization - carbon concentration at the surface of the steel) (0.5* 6700.0 - 6700.0 )/ ( 213.5 - 6700.0...
December 15, 2012

chemistry
74.5years X (multiply) with 5.64386
December 15, 2012

Chemistry
**We are here to help each other on this forum. Hope the info below helps'! Step 1: ξ= (0.5 * carbon concentration at the surface of the steel - carbon concentration at the surface of the steel)/ (carbon concentration in the steel before carburization - carbon ...
December 15, 2012

Chemistry
Step 1: ξ= (0.5 * carbon concentration at the surface of the steel - carbon concentration at the surface of the steel)/ (carbon concentration in the steel before carburization - carbon concentration at the surface of the steel) (0.5* 7345.0 - 7345.0)/ ( 235.0 - 7345.0)= ...
December 15, 2012

Chemistry
Step 1: (0.5* 6155.0 - 6155.0)/ ( 211.5 - 6155.0)= erf(ξ) Step 2: erf(ξ < 0.6), use the approximation erf ξ = ξ Step 3: t= d^2/4*D*ξ^2 d=59.0 x 10-2 cm D=3.091 x 10-7 cm2/s Step 4: t in sec -> hours Conversion seconds to hours is total/(60x60)
December 15, 2012

Chemistry
You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 211.5 ppm and is initially uniform through the thickness of the steel. The atmosphere of...
December 15, 2012

CHEMISTRY
(6.023*10^23)/(12.05)=m m*(3.091*10^-8)*(10^-2)=
December 15, 2012

chemistry
(6.023*10^23)/(12.05)=m m*(3.091*10^-8)*(10^-2)=
December 14, 2012

chemistry
Thank you someguy
December 14, 2012

chemistry
The answer 1.598e14 was not right for me too. Any ideas what happen and how to write it out?
December 14, 2012

chemistry
(6.023*10^23)/(12.05)=m m*(3.091*10^-7)*(10^-2)=
December 14, 2012

CHEMISTRY
a)7.23 b)475
December 14, 2012

CHEMISTRY
(6.023*10^23)/(12.05)=m m*(3.091*10^-8)*(10^-2)=
December 14, 2012

chemistry
As its Si: 5.00*10^22 / (gallium level*10^-2) by someguy
December 14, 2012

chemistry
Thank you
December 14, 2012

chemistry
Decrease the cooling rate. Add CaO to the glass melt.
December 14, 2012

chemistry
Thank you someguy
December 14, 2012

chemistry
how do I believe you?
December 14, 2012

chemistry
a) 7.23 b) 475 ev
December 14, 2012

chemistry
Answer is: 193000
December 14, 2012

chemistry
(6.023*10^23)/(12.05)=m m*(3.091*10^-8)*(10^-2)=
December 14, 2012

chemistry
840
December 14, 2012

chemistry
a 7.23
December 14, 2012

chemistry
(b) II Specimen A should allow silver to diffuse more quickly due to its smaller grain size and increased grain boundary area.
December 14, 2012

chemistry
110
December 14, 2012

Chemistry
Thank you Chemistry ;)
December 14, 2012

Chemistry
(a) The figure above shows how the energy of a system varies as a chemical reaction proceeds. Match the numbers features labeled on the figure above to their corresponding statements below: energy state of the reactants: 1/2/3/4/5 activation energy of the reaction: 1/2/3/4/5 ...
December 14, 2012

Chemistry
Thank you all.
December 14, 2012

Chemistry
The half-life of a first order reaction is determined to be 85.5 years. How long will it take for the concentration of the reactant to reach 2% of its initial value?
December 14, 2012

Chemistry
840
December 14, 2012

Chemistry
A formation energy of 1.11 eV is required to create a vacancy in a particular metal. At 777oC there is one vacancy for every 22,200 atoms. At what temperature will there be one vacancy for every 11,100 atoms?
December 14, 2012

Chemistry
Thank you Anonima
December 14, 2012

Chemistry
How could one lower the glass transition temperature of a germate (GeO2) glass? Select all possible ways. i)Increase the cooling rate. ii)Decrease the cooling rate. iii)Add SiO2 to the glass melt. iv)Add CaO to the glass melt.
December 14, 2012

Chemistry
1.5455*10^19
December 14, 2012

Chemistry
As its Si: 5.00*10^22 / (gallium level*10^-2) by someguy
December 14, 2012

Chemistry
The answer 1.598e14 was not right for me too. Any ideas what happen and how to write it out?
December 14, 2012

Chemistry
Chemical analysis of a silicon crystal reveals gallium at a level of 3.091X10^-2 atomic percent. Assuming that the concentration of thermally excited charge carriers from the Si matrix is negligible, what is the density of free charge carriers (free carriers/cm3) in this Si ...
December 14, 2012

Chemistry
Thank you alex and babalovic for B)and anonim for A)
December 14, 2012

Chemistry
You are conducting experiments with your x-ray diffractometer. (a) A specimen of molybdenum is exposed to a beam of monochromatic x-rays of wavelength set by the Kα line of silver. Calculate the value of the smallest Bragg angle, θhkl, at which you can expect to ...
December 14, 2012

Chemistry
Thank you anonymous
December 14, 2012

Chemistry
The diffusion coefficient of silver (Ag) in copper (Cu) has the following values: T (K) D (m2s-1) 923 5.42 x 10-16 1173 1.34 x 10-13 (a) Calculate the activation energy for diffusion of silver in copper. Express your answer in units of J/mol. (b) You have two specimens of ...
December 14, 2012

Chemistry
Thank you Anonymous and Anonima
December 14, 2012

Chemistry
The glass panels of a sky roof need to be coated in order to screen out ultraviolet radiation (10-400 nm wavelength) but without color distortion in the visible spectrum. Candidate coating materials are gallium nitride (GaN) with a band gap,Eg, of 3.2 eV, or gallium arsenide (...
December 14, 2012

Chemistry
Thank you qwerty, Rufus for A)IV and Anonymous for B) VI
December 14, 2012

Chemistry
Odesa, the answer for b is VI) [1-2 2-] and thank you anonymous.
December 14, 2012

Chemistry
For b) [1-2 2-] is which number? (i,ii,iii etc?)
December 14, 2012

Chemistry
(a) Identify the feature below using correct crystallographic notation. i) (2 1 0) ii) (^-1 1/2 0) iii) (^-2 0 1) iv) (2 ^-1 0) v) [2 1 0] vi)[^-1 1/2 0] vii) [^-2 0 1] viii) [2 ^-1 0] (b) Identify the feature below using correct crystallographic notation. i) (1 ^-2 2) ii) (^-...
December 14, 2012

Chemistry
110
December 14, 2012

Chemistry
Show that a conventional x-ray generator is incapable of generating x-rays of wavelength as low as 10-11m. Do this by determining the identity of the target (in atomic number, Z) which would be needed to generate such x-rays.
December 14, 2012

Chemistry
Thank you all.
December 14, 2012

Chemistry
The answer 9.31 is not right can any give a formula.
December 14, 2012

Chemistry
A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.31 kg m-3. Under these conditions the total surface area of the balloon is 0.11 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
December 14, 2012

Chemistry
Thank you anonymous and Ibvda
December 14, 2012

Chemistry
(a) Cadmium telluride (CdTe) is a semiconductor witha band gap, Eg, of 1.45 eV. Calculate the value of the absorption edge of this material. Express your answer in meters. (b) Shown below are several % absorption vs. wavelength diagrams. Identify the correct diagram for a ...
December 14, 2012

Chemistry
Got the answer 297.622419061 hours.Thank you all for the advise, check through, and help, great way to make sure all of us don't use up our submissions. Again thank you bra, qwerty and yamy.
December 14, 2012

Chemistry
You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 193.5 ppm and is initially uniform through the thickness of the steel. The atmosphere of...
December 14, 2012

Chemistry
b) i
December 13, 2012

Chemistry
Consider the gold-platinum system which has a value of delta w of -4250 J/mole; (a) Calculate the enthalpy of mixing for a solution of 10% platinum and 90% gold. Express your answer in units of kJ/mole. (b) Is the dissolution of 10% platinum into gold an endothermic or an ...
December 11, 2012

Chemistry
qwerty and paul are right. Thank you both.
December 11, 2012

Chemistry
The fictitious compound, pandemonium carbonate Pn(CO3)2 hase a Ksp=3.091x10^-9M3 in water at room temperature. Calculate the solubility of Pn(CO3)2 in an aqueous solution of 1.11 M pandemonium sulfate Pn(SO4)2 (aq) . Express your answer in units of molarity.
December 11, 2012

Chemistry
Answer the following questions by referring to the Cu-Al phase diagram shown below. (a) What is the lowest temperature at which a liquid can be found in a system of any composition of Cu-Al ? (b) A common alloy composition used in airplanes is 4 at. % Cu - 96 at. % Al. For ...
December 11, 2012

Chemistry
Thank you
December 11, 2012

Chemistry
The solubility of the fictitious compound, administratium fluoride ( AdF3 ) in water is 3.091x10^-4M . Calculate the value of the solubility product Ksp .
December 11, 2012

Chemistry
Thank you
December 11, 2012

Chemistry
(a) The phase diagram of the binary system, neodymium-scandium ( Nd-Sc ) is given below. There are two polymorphs in the solid state: alpha which is hexagonal close packed (HCP) and beta which is body-centered cubic (BCC). Identify all phases present at points 1, 2, and 3. ...
December 11, 2012

Chemistry
Thank you
December 11, 2012

Chemistry
Question One Lead chloride dissolves in water according to PbCl2(s)<-> Pb^2+ + 2Cl^- (aq) The solubility in pure water has been measured to be 4.44g . L^-1 . Calculate the solubility product of lead chloride in pure water. Your answer should be in units of molarity ...
December 11, 2012

Chemistry
Thank you
December 11, 2012

Chemistry
Question One The fictitious compound, pandemonium fluoride ( PnF2 ) has a Ksp value in water of 3.091x10^-9 M^3 at room temperature. Calculate the solubility of PnF2 in water. Express your answer in units of molarity. Question Two How would you expect the solubility of ...
December 11, 2012

Chemistry
Thank you
December 11, 2012

Chemistry
Question One: Comment on the solubility of hydrogen ( H2 ) in liquid ammonia ( NH3 ). State whether you expect hydrogen to be highly soluble or almost insoluble, and explain why. i)Highly soluble due to hydrogen bonding. ii)Highly soluble due to compatible nature of bonds. iii...
December 11, 2012

Chemistry
Thank You
December 11, 2012

Chemistry
Here is the phase diagram of water with attention given to phases at high pressure. Name all phases present at the markers 1, 2 and 3. Phases present at 1: Liquid I II III IV V VI VII VIII IX Phases present at 2: Liquid I II III IV V VI VII VIII IX Phases present at 3: Liquid ...
December 11, 2012

Chemistry
Free Surface Vacancies
December 1, 2012

Chemistry
H6P8: Elongation A steel cable 10 m long is pulled in tension with a stress of 350 MPa. Assume that the Young's modulus of the steel cable is about 200 GPa. If only elastic deformation occurs, what is the resultant elongation in cm?
November 29, 2012

Chemistry
H6P7: Young's Modulus Rank the following 3 classes of materials in order of increasing typical Young's Modulus: metals such as copper, plastics such as HDPE (high density polyethelene), and ceramics such as alumina (Al2O3). Do not look up the values of Young's ...
November 29, 2012

Chemistry
H6P6: Urbium Oxide First Part of the Question: Urbium (Ur) is an upscale element found in big cities. Its oxide (UrO2) is not very stable and decomposes readily at temperatures exceeding 66∘ C. The figure below shows how the rate of reaction varies with the concentration...
November 29, 2012

Chemistry
N2O5 dissolved in CCl4 decomposes to give N2O4 and O2. The reaction is first order with a half-life of 1234 seconds. How long will it take, in seconds, for the concentration of N2O5 to fall to 1.1% of its initial value?
November 29, 2012

Chemistry
Administratium bromide (AdBr) decomposes readily at temperatures exceeding 37°C. The figure below shows how the rate of reaction varies with the concentration of AdBr. The rate, r, is in units of M s-1 and the concentration of AdBr, c, is in units of M (mole L-1). The ...
November 29, 2012

Chemistry
The fictitious compound, arrhenium fluoride (AhF), reacts with itself to form a dimer with the formula Ah2F2. The reaction is second order in AhF. The value of the rate constant is 4.091×10−3 M−1s−1. What is the initial rate of reaction in a reactor ...
November 29, 2012

Chemistry
You have a single crystal of 100% pure gold. Identify which of the following defects you would expect to be present at room temperature. Free surface Grain boundaries Vacancies Inclusions Substitutional impurity atoms Interstitial impurity atoms
November 29, 2012

Chemistry
Metals yield at a stress much lower than those calculated on the basis of their bond strength alone. This is explained by the presence of defects. Identify the principal defects responsible for this observation. A)Grain Boundaries B)Interstitial Metal Atoms C)Vacancies D)...
November 29, 2012

Chemistry
Thank you.
November 24, 2012

Chemistry
Name the following crystallographic features below using proper crystallographic notation. Image One [2ˉ21] [1ˉ12ˉ] [1ˉ1(1/2)] [(1/2)(1/2ˉ)1ˉ] Image 2 (1ˉ02) (21ˉ0) (201) (1ˉ02ˉ) The wrong answer as far I known in Image One:[(1...
November 24, 2012

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