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Posts by raj

Total # Posts: 311

Chemistry
I understand why PCl3 is zero order, but I don't get why Cl2 is second order.

Chemistry
In the reaction PCl3 + Cl2 ---> PCl5. If the rate doesn't increase when the concentration of PCl3 is doubled and the rate increases by a factor of four when the concentration of Cl2 is doubled, how would I write the rate law for the reaction?

Chemistry
If I2 reacted with hexane, how would we know, which carbons the Is go on? Would only one of the iodine go to the hexane and the other form HI, or would they both join and H2 is a by-product?

Chemistry
Sorry, I meant hexane and not toulene. For hexane, I would expect a reaction to occur, but the colour stayed dark purplish. Would HI form here?

Chemistry
For a lab, I had to react toulene with 1% I2 in dichloromethane. Would HI form as a result of this? Logically, I think there would be no reaction because toulene looks too stable. But a colour change occured. Why would this happen?

Chemistry
Nevermind.

Chemistry
Given the weight of phenacetin and its percentage yield...how would I calculate its melting point?

Chemistry
Write the structure for the alkane: molecular mass = 72 u; forms four monochlorination products. Well since its 72u and its an alkane, I figured out that the formula is C5H12. But what does it mean that it "forms 4 monochlorination products"?

Chemistry
If I am given a molecular hydrocarbon structure, how would I be able to tell how sp3 hybridized carbons it possesses? Like my current question asks How many sp3-hydridized carbon atoms does 11-cis-retinal possess?

Antiderivatives
I can't figure this one out, the antiderivative of x^-1. I thought it would be c, but the derivative of c is zero.

Math
4/5 - 1/2 Find a common denominator and solve.

Chemistry
Thanks, for the help, although the last one doesn't look right, I understand it now. Thank You.

Chemistry
Can someone explain for organic chemistry naming, when something would be given something like "iso" in it or when we would say "s-butyl" or "t-propyl" etc., with "s" meaning secondary and "t" meaning tertiary.

Chemistry
How can I tell whether something is a weak, strong, or non-electrolyte? I know non-electrolytes do not ionize, strong almost completely ionize and weak only partially. But how would I be able to tell? Like, something like KOH is a strong electrolyte because it can ionize into ...

Chemistry
45

Chemistry
In a thermochemistry experiment the reaction of 0.0857 g of an unknown metal and an excess of 4.0 M HCl resulted in a 0.210 mL decrease in the volume of an ice/water mixture. Calculate the enthalpy of this reaction per 1 g of metal reacted. Needed data: density of water at 273...

Chemistry
The reaction between 0.055 g of calcium with an excess of water was carried out in an ice calorimeter. The volume of water in the calorimeter decreased by 0.20 mL during the reaction. Calculate the enthalpy of the reaction (in kJ/mol).

Chemistry
Oh, alrite so then heres what I get. 2 Cl(g) --> Cl2(g) exo-on H2O(l) --> H2O(g) endo-by 2 H2(g) + O2(g) --> 2 H2O(l) exo-on 2 Li(s) + H2O(l) --> 2 LiOH(aq) + H2(g) endo-by 3 NaN3(s) --> Na3N(s) + 4 N2(g)endo-by

Chemistry
When given a chemical reaction, how would I know whether a reaction is endo or exothermic and whether work is done on the system or by the system. Without using any calculations. So I have a couple reactions which I have to use chemical reasoning to to determine. 2 Cl(g) -->...

Chemistry
You have to determine the molar mass of CaCO3, by getting the molar mass of Ca and the molar mass of C, and the molar mass of O multiplied by 3 (since there are 3 oxygen atoms). You would get 100.087 g/mol. You would then do the mass/molar mass. 30.6/100.87 = your answer

Chemistry
How did you get 1 cal/g*c....is that a calculated constant or is manual conversion required? The answer I get using your method is 96.4kg, which is correct.

Chemistry
Wait, I did it wrong. q = mH(Tf - Ti) m = q/H(Tf-Ti) m = 675/[4.18x7] m = 23.06 But its still the wrong answer.

Chemistry
m = q/[(H)(Tf-Ti)] m = (4.18)[(675)(37-30)] m = 8.84 x 10^-4 I'm pretty sure this is wrong.

Chemistry
A person falls in water at 0 degrees C. After 20 minutes of exposure, they are suffering acute hypothermia, as their core body temperature has dropped to 30.0 degrees C. Assume that a person’s heat capacity can be approximated by the heat capacity of water, 4.18 J/g/oC. ...

Chemistry
So for ii) If HClO2 is the stronger base, then does that mean that ClO2 is also the stronger base?

Chemistry
Sorry, for iii) I meant that I think Cl3CCOO- is the stronger base.

Chemistry
For each of the pairs of bases below, choose the stronger base: (i) NH2- or NH3 (ii) ClO3- or ClO2- (iii) Cl3CCOO- or Cl2HCCOO- For i) I think it is NH2-, because it has a stronger ability to attract an H+ atom to become de-ionized. For ii) I don't know how to determine it...

Chemistry
Do I have to make equations and see which one forms a precipitate again? I don't think its H2CO3 or HCl because that would not minimize the effect of acid rain. So its either the 2 bases or CCl4. CCl4 + SO2 ==> CO2 + SCl4 ClOH + SO2 ==> CO2 + SOH Ca(OH)2 + SO2 ==>...

Chemistry
Stelco has been recently legislated to reduce total SO2 emissions from iron smelting operations. Select the most effective chemical reagent to desulfurize Stelco’s gas emissions as a strategy to minimize the environmental impact of acid rain in eastern Canada and why? ...

Chemistry - DrBob222
Alright. Thank you so much for the help today.

Chemistry - DrBob222
About these: NaCl + Zn No reaction CaCl2 + NaOH No reaction CaCl2 + Zn No reaction CaCl2 + Na2SO4 No reaction How would these give no reaction. NaCl + Zn ==> ZnCl + Na CaCl2 + NaOH ==> Ca(OH)2 + NaCl CaCl2 + Zn ==> ZnCl + Ca CaCl2 + Na2SO4 ==> CaSO4 + Na

Chemistry - DrBob222
Wait, AgNO3 with any unknown with Cl present would form a precipatate. So I can use that to tell between HNO3 and HCl. So now is the whole thing correct?

Chemistry - DrBob222
Alright, I've made a list of reactions that would produce precipatations. NaCl + Zn CaCl2 + NaOH CaCl2 + Zn CaCl2 + Na2SO4 CuSO4 + NaOH CuSO4 + Zn NaOH + AgNO3 NaOH + Zn BaOH2 + AgNO3 BaOH2 + Zn BaOH2 + Na2SO4 So this way I can figure if it is NaCl, CaCl2, CuSO4, NaOH,Ba(...

Chemistry
I posted before about designing a procedure to determine two unknowns (1 solid, 1 solution). The possible solutions were: NaCl, CaCl2, CuSO4, NaOH,Ba(OH)2, HCl, HNO3, or H2O. The reagents given are: NaOH, HCl, AgNO3, Zn metal, Na2SO4, and H2O. The procedure I've designed ...

Calculus
f(x) = x(x^2 + 1)^(1/2) f'(x) = (x)(1/2)(x^2+1)^(-1/2)(2x) + (1)(x^2+1)^(1/2) f'(x) = (x^2)(x^2+1)^(-1/2) + (x^2+1)^(1/2)

Chemistry
Oh thanks. But can you tell me what this means "quantify the amount of solute in the solution".

Chemistry
I have to do lab experiment where I design a procedure to determine the identity of two unknowns given to me. One will be a solid and one will be a solution. I also have to quantify the amount of solute in the solution. The possible solids it could be are NaCl, KNO3, KHP, Zn, ...

math
This is probably really easy to work out: x^2=(x-2)(x+3) ^meaning to the power of I've got to: x^2=x^2+x-6 Don't know what to do next

math
Solve the following equations giving any roots in terms of pi in the .......? interval -2pi ≤ 0 ≤ 2pi. a) 2cos²Θ + sin²Θ = 0 b) 2cos²Θ + sin²Θ = 1 c) 2cos²Θ + sin²Θ = 2

Chemistry
Copper dissolves in nitric acid, producing copper (ll) nitrate. After reaction with sodium hydroxide and heating, copper nitrate changes to copper (ll) oxide. Calculate the percent yield of this process if 1.235 g of copper produced 1.452 g of copper oxide.

Physics
Mars' moon Phobos has a mass of 1.07x1016 kg and a mean radius of 11.1 km. Let's say our rocket blasts off from the surface of Phobos when Phobos is 9500 km from the surface of Mars. Does the rocket have to work harder to escape from the gravitational pull of Phobos or...

science
to find the vertical velocity we use 40*cos(30)=34.6 m/s W= KE = 1/2 mv^2 =1/2*0.15*34.6^2= 89.797 J or 90 J

algebra
70 = (75+63+68+x)/4 ...with x being what he must get. So you solve that: 70(4)-75-63-68 = x x = 74 So therefore, Sam must get a 74 or above to get a C grade. x => 74

Physics
Oh nvm, you mean F = 1/d^2 Got it...thanks.

Physics
but what is the 3^2 for? If the 3 is for the distance being tripled...what about the exponent 2?

Physics
If the distance between two objects is tripled, by what factor will the gravitational force between them change?

Chemistry
A sample of solid monoprotic acid with molar mass equal to 137.9 g/mol was titrated with 0.1879 M sodium hydroxide solution. Calculate the mass in grams of acid to be used if the volume of NaOH to be used is 25 mL.

Chemistry
If 1.000 kcal of heat is added to 1.700 L of oxygen in a cylinder at constant pressure of 1.00 atm, the volume increases to 2.100 L. Calculate the total energy change for this process.

Science
At what latitude (on Earth) is the elevation of the South Celestial Pole greatest?

Trigonometry
is that supposed to be zero or theta? if its theta: 1) theta = 23.6 2) theta = 53.1

Math
Find all values of x in the interval [0, 2 pi] that satisfy 2 cos x-1 = 0. cos x = 1/2 x = 60 How do I find the other value of x?

Chemistry
That means that AgNO3 is the limiting reactant as it has 0.0033 moles compared to 0.0039 for silver nitrate. But I don't get the last part you said. What same number of moles of silver bromate would I get? Do you mean same number of moles as the limiting reactant? Meaning ...

Chemistry
0.658 g of potassium bromate and 0.562 g of silver nitrate are added to 388 mL water. Solid silver bromate is formed, dried, and weighed. What is the mass, in g, of the precipitated silver bromate? Assume silver bromate is completely insoluble. I've calculated the moles ...

Chemistry
A 35 mL solution of HCl, reacts completely with 20 mL of 0.25 M KBr. What is the molarity of the HCl solution?

Calculus
A spherical balloon with a radius "r" inches has volume V(r)=(4/3)(pi)(r^3). Find the function that represents the amount of air required to inflate the balloon from a radius of "r" inches to a radius of r+1 inches.

Calculus
What is wrong with the following reasoning??? f(x) = 2^x f'(x) = x[2^(x-1)] Although n x^(n-1) is the derivative of x^n, you cannot apply similar rules when x is the exponent and the number being raised to a power is a constant. The derivative of b^x, where b is a constant...

Chemistry
Are propane, methoxymethane, and ethanol soluble in water? yes http://www.chem.lsu.edu/lucid/tutorials/solubility/Solubility.html Henry is wrong.

Chemistry
Calculate the end point pH, when 25 mL of 0.01 mol/L HCl solution reacts exactly with 25 mL of 0.1 mol/L NH4OH solution. NH3 Kb = 1.8 x 10^-5 This will be the pH of NH4Cl solution. NH4+ + HOH ==> NH3 + H3O^+ Ka = Kw/Kb = (NH3)(H3O^+)/(NH4^+). Solve for H3O^+, then pH = - ...

Chemistry
Calculate the pH of a solute where 24.5 mL of 0.1 mol/L HCl is added to 25.0 mL of 0.1 mol/L NaOH. How much excess OH is there? .5ml .1M or 5E-5 moles. That is in a volume of 49.5ml So if OH concentration is that moles/volume, what is the H+ concentration? Remember the product...

Chemistry
Classify the following as: Weak or strong acid, weak or strong base, salt (from weak/strong acid and base). If appropriate, split the formula into its component ions. HNO3 So far, all I have is: HNO3 + H2O -> NO3^- + H3O^+ And I know HNO3 is a strong acid. What would I do ...

Chemistry
Use the Bronsted-Lowry definitions to identify the two conjugate acid-base pairs in the following acid-base reaction: H20 + H20 <-> H30^+ + OH^- Let's see what you think on this after the previous post. Just remember, the acid is the one that HAS the H and the base ...

Chemistry
Use the Bronsted-Lowry definitions to identify the two conjugate acid-base pairs in the following acid-base reaction: HCO3^- + S^2- <-> HS^- + CO3^2- I got it. HCO3^- is the base in the pair with CO3^2-. S^2- is the acid in the pair with HS^-. Would you believe you have ...

Chemistry
Zn + PbCl2 --> ZnCl2 + Pb The initial mass of a zinc strip is 2.684. After being left overnight in a lead (II) chloride solution, the mass of zinc is 2.581g. Calculate the Ksp of lead (II) chloride. So far I have: PbCl2 --> Pb(aq)2+ + 2Cl(aq)- Ksp = [Pb(aq)2+] [Cl(aq)-]^...

English
How is Hamlet a hypocrite towards Ophelia? I have one example, which is that he says he loves her but is the cause of her death because he rejects her and kills her father, which causes her madness and subsequent death. I need one more example, but I can't think of him ...

English
I posted this yesterday, that I need to modernize an Ancient Greek myth. bobpursely replied with an idea that I could do the Siren sisters as cheerleaders, but I couldn't find a myth about them, they're in two different myths. Like I've been thinking of myths such ...

English
I have to modernize an Ancient Greek myth, does anyone have any ideas? Sure. Reset the place and time of the Siren sisters (cheerleader sisters?) occupying a booth at the local Ice Creame shop, tempting Jason (basketball dude hero), Argo (Computer Programmer dude), and ...

Calculus
Why can't a equal 1 in y=log(base a) x. And why is x always positive in that? Hmmmm. a^y=x (from the problem statement). If a were to equal 1, then x would be 1 (1 to any power is 1). So if a is not one, but a positive number, then x has to be a positive number, if one is ...

Calculus
Find the inverse of each relation: y = (0.5)^(x+2) and y = 3log base 2 (x-3) + 2 For the first one I got y=log base 0.5 (x+2)...but the answer in the back of the textbook says that it is not x+2, but x-2. Can someone tell me why it would end up being x-2 and help me with the ...

Calculus
Express in exponential form: y = -log x with base 2 the - in front is like a -1 multiplied so write it as y = log2 x-1 then 2y = 1/x

English
How is Hamlet hypocritical with Rosencrantz and Guildenstern? Provide 2 examples. Please note that we don't do students' homework for them. Our tutors try to give you the information to help you complete your assignment on your own. Be sure to go back into your ...

Calculus
If f(x) is a continuous function, find the constants a and b such that f(x) = { -x -3 <= x <= -2 ax^2 + b -2<x<0 b x=0

Calculus
4) f(x)= { 3x^2 x< and equal 1 { ax+ b x > 1 What is the relation between a and b if the function is continuous for allof x.

Calculus
Create a function that has a graph with the following features: Two vertical asymptotes: x=1, x=3. One horizontal: y = -1. And x intercepts= -2, 4 how about f(x) = ((x+2)(x-4))/((3-x)(x-1)) ?

English
Hi, I'm writing an essay on "what makes a city world-class"...I have all of my points and everything set, I'm just stuck on how I should start my essay. I can't think of any good introductory sentence. Your introductory sentence should be something VERY ...

Biology
How is commercial root beer carbonated? Yeast-carbonated root beer contains a small amount of alcohol. ... which contain the same sort of artificial colors and flavors as commercial root beers. Since this is not my area of expertise, I searched Google under the key words "...

Chemistry
Can hypochlorite ions oxidize bromide to bromine? In acid solutions, yes. That's the old qual test for bromide. Shake a solution of the unknown with NaOCl, this oxidizes bromide to bromine, and the bromine colors the carbon tetrachloride layer (added previously) yellow. Of...

Chemistry
When hypochlorite ions act as an oxidizing agent, hydroxide ions are formed. What will this do to iron (II) or to iron (III) ions? Both Fe(OH)2 and Fe(OH)3 are insoluble in an aqueous solution.

Biology
What are the components of a photsynthetic unit, and what roles do they play? In which part of the chloroplast are photosynthetic units located?

Biology
Write an equation to summarize the photo reaction of photosynthesis. Since this is not my area of expertise, I searched Google under the key words "photosynthesis equation" to get these possible sources: (Broken Link Removed) http://en.wikipedia.org/wiki/...

English
I need to prove that Hamlet cares about/loves his mother or cared about her/loved her at one point. Since this is not my area of expertise, I searched Google under the key words "Hamlet mother love" to get these possible sources: http://72.14.253.104/search?q=cache:...

Chemistry
Does the conversion of hydrogen peroxide to oxygen involve oxidation or reduction? What substance is acting as the oxidizer or reducer? and Does the conversion of hydrogen peroxide to water involve oxidation or reduction? What substance is acting as the oxidizer or reducer? ...

English/GuruBlue
I needed to write an essay on how Hamlet is a hypocrite and my three points were that he doesn't obey his father right away, he says he loves his mother but treats her badly, and he says he loves Ophelia but he is the cause of her madness. But now, my topic has been ...

GuruBlue/English
Yesterday, I asked the question about my thesis statement for Hamlet. Heres what I wrote: Hi, I'm writing an essay on how Hamlet is a participant of hypocrisy. Can anyone help me write a thesis statement. My points are that his father tells him to avenge him, but Hamlet ...

English
Hi, I'm writing an essay on how Hamlet is a participant of hypocrisy. Can anyone help me write a thesis statement. My points are that his father tells him to avenge him, but Hamlet takes a long time to do it, how Hamlet says he loves Ophelia but is the cause of her death, ...

English
Hi, If anyone has read Hamlet...I have to write an essay showing how Hamlet is a hypocrite or similar. I need 3 main points of proof. I only have one, which is that Hamlet says he loves Ophelia but hes the cause of her death and he shunned her. I need two more points. His ...

Chemistry
How come two non-polar substances are able to easily mix? Like dissolves like. Yes, I know that, but is there any explaination to that relating to the bonds? http://www.newton.dep.anl.gov/askasci/chem03/chem03348.htm

Chemistry
Look up the boiling points and relative molecular masses of water, hexane, and ethanol. Try to explain the relative magnitudes of their boiling points in terms of polarity. I know that ethanol and water are polar and that hexane is non-polar. Also, 6)

Biology
How do nucleaotides join to form nucleic acids? Name the bond formed. http://www.sparknotes.com/biology/molecular/structureofnucleicacids/section1.html

Chemistry
How would you make a starch molecule? What is the name of the bond formed between glucose molecules? I think I got it. They are formed by long chains of glucose molecules joined together by a glycosidic link. Can anyone confirm if this is correct? I believe you are right. ...

Chemistry
How would you make a starch molecule? What is the name of the bond formed between glucose molecules? Answered above.

Chemistry
Using molymods make 2 ring structures of glucose and join them through a condensation reaction between carbon 1 on one molecule and carbon 4 on the other. What molecule is formed through this procedure?

Biology/Chemistry
What kind of isomers can amino acids form? Which isomer is present in most living organisms? don't major compounds of living organisms consist of modifications of hydrocarbons Although D amino acids can be found in nature, only the L isomers are used to form proteins. The ...

Biochemistry
What kind of isomers can amino acids form? Which isomer is present in most living organisms?

Chemistry
When the halogens form ionic compounds, what is the ion charge of the halide ions? negative one

Calculus
Factor the following: y = (x-a)^5 . (x-c)^5 . (a-c)^5 It looks already factored to me

Chemistry
What is the empirical distinction between emission and absorption spectra? In general terms, how did Niels Bohr explain each of these spectra? In general terms, emission spectra are obtained when the electron is at a high energy level and it falls to a lower energy level. In ...

Physics
A hockey puck travelling at 26 m/s [E 22* S] rebounds off the board at 21 m/s [E 22* N]. The puck is in contact with the board for 0.0025 seconds. Determine the average acceleration of the puck over the interval. average acceleration= change in velocity/time a= (Vf - Vi)/time ...

english
i am unable to this question complete the following by adding noun clause a)the fact is that__________________ b)this is a clear proof_______________ complete the following by adding noun clause a)Thefact is that______________________ b)This clearly proof__________________ The...

Algebra & Discrete Geometry
Determine a vector of magnitude 2 that is parallel to a=(-3, 4).

Physics
Calculate the period of the wave if it makes 10 vibrations in 2 seconds. Does anyone know the formula for this? frequency = (number of waves) divided by(observation time) = 10/2 = 5 Hertz period = 1/frequency = ?

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