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July 24, 2014

Search: For Dr.Bob222

Number of results: 79

:)
Thank you Dr.Bob222
November 30, 2010 by Tosha

science
dr.bob222 i dont get it can u give me the answer
November 15, 2009 by sophie

Chemistry(Dr.Bob222)
What does it mean for something do to be neutralized? Is that when the [H+]=[OH-]? or is that totally wrong?
November 20, 2013 by K

chemistry *Dr.Bob222
Why do firefighters recommend the use of a deluging volume of water when extinguishing an oxidizer-supported fire?
December 22, 2012 by Cameron

Chemistry Dr.Bob222==> Take a Look
what is this compound, it has a mf of c6h12o i. imgur. com/gCgw0Hi. png What may be the structure from the IR and H NMR data? This question is bugging me.
January 25, 2013 by Devron

Thank you Dr.Bob222
Thank you, you don't know how much you have help me with my chem class...thank you so much..your the best!!
November 11, 2010 by julia

(19) Chemistry - Science (Dr. Bob222)
Use the following information to answer this question: Cu+(aq) + e- → Cu(s) E = 0.521V Cu2+ (aq) + e- → Cu+ (aq) E = 0.153 V. Given these half cell reactions, an aqueous solution of Cu+ ion in the absence of O2(g) : A. will be thermodynamically stable B. will ...
May 8, 2014 by Ana

Chemistry - Science (Dr. Bob222)
How many mmol ( millimoles) of HCl must be added to 130.0 mL of a 0.40M solution of methyl amine (pKb = 3.36) to give a buffer having a pH of 11.59? Thank you for your help!
May 6, 2014 by Ana

To Dr.Bob222
Is teh answer for teh nine protons and 10 electrons thing F^1- Yes, I answered to that effect at the original post. Its the fluoride ion.
October 15, 2006 by Googly Eyez

dr.bob222
when you get a small little chance can you check my math in last message i posted. thank you. I read the post earlier but didn't post a response because I was confused by the c in the formula.
January 30, 2007 by Jasmine20

Chemistry - Science (Dr. Bob222)
Consider reaction below: 50H3O^+(aq) + 7Cr2O7^2-(aq) +3I_2(aq) --> 6IO_4^-(aq) + 14Cr^3+(aq) + 75H2O (l) How many electrons are transferred in this reaction?
April 14, 2014 by Adrik

Chemistry - Science (Dr. Bob222)
Ammonium metavanadate reacts with sulfur dioxide in acidic solution as follows (hydrogen ions and H2O omitted): xVO3^^ + ySO2 → xVO^2+^ + ySO4^2^ What is the ratio of x : y? A. 1 : 1 B. 1 : 2 C. 2 : 1 D. 1 : 3 E. 3 : 1
May 3, 2014 by Ana

Chemistry-Help Dr. Bob222
If a weak acid has a dissociation constant of 6.4 x 10^-6, what is the pH of a solution of this acid in a 0.10 molar concentration? I still don't understand the equation you gave me. My textbook doesn't break it down like this, so I'm confused as to where to plug the 0.10 M in.
December 14, 2010 by Maddy

Chemistry - Science (Dr. Bob222)
Liquid chloroform (CHCl3) is placed in a closed container and allowed to equilibrate with chloroform vapor. With the temperature held constant, additional chloroform is introduced into the system, and the vapor-liquid equilibrium is reestablished. Following this, the ...
May 10, 2014 by Ana

Dr bob222,math
How is 6p^5q^3 x 9p^5q^3 / 5p^5q^5= 30p^5q because isn't it both have the same exponents and letters therefore they should cancel and be left with 30q^2 The equation started at as 25 for the second part of the numerator and not 9. 6p^5q^3 x 25p^5q^3/5p^5q^5 = (150p^10q^6)/(5p^...
December 14, 2006 by Jasmine20

Chemistry - Science (Dr. Bob222)
Consider the kinetic data given in the table below for the first order reaction: What is the value of the activation energy? A_2_--> 2A Expt. Initial [A2] Temp. Initial Rate mol/L (C) [A2]s1 1 0.10 100 1.2 x 103 2 0.20 200 4.8 x 103 3 0.15 ? 4.5 x 103
April 16, 2014 by Ana

Chemistry - Science (Dr. Bob222)
Consider the kinetic data given in the table below for the first order reaction: What is the value of the activation energy? A_2_--> 2A Expt. Initial [A2] Temp. Initial Rate mol/L (C) [A2]s1 1 0.10 100 1.2 x 103 2 0.20 200 4.8 x 103 3 0.15 ? 4.5 x 103
April 16, 2014 by Ana

Chemistry - Science (Dr. Bob222)
Ammonia is a weak base with a Kb of 1.8 x 10-5. A 100.0 mL sample of 0.13 M aqueous solution of ammonia (NH3) is mixed with 87 mL of 0.15 M solution of the strong acid HCl, calculate the pH of the final solution. A) 2.9 B) 11.1 C) 8.8 D) 5.2 E) None of the above
May 6, 2014 by Ana

Dr.Bob222 Chem
I believe that you are correct because you have more experience in G-chem then I have. But how does doubling the reaction rate double the k value? Isn't k just a constant for a particular reaction?
February 1, 2013 by Devron

chemistry - (Dr. Bob222)
The rate constant for a second order reaction has the value of 2.5 x 103 Lmol1s1. If the initial concentration of reactant is 3.5 molL-1, what will be the molar concentration of the reactant after 2.5 minutes?
April 16, 2014 by Ana

(5) Chemistry - Science (Dr. Bob222)
Consider a buffer made from 0.13 M sodium acetate and 0.10 M acetic acid in 1L. What amount of KOH must be added to cause an increase of the pH by 0.14? A) 0.048 mol B) 0.038 mol C) 0.028 mol D) 0.018 mol E) 0.008 mol
May 6, 2014 by Ana

Chemistry (Dr. Bob222)
How can you tell if something is highly concentrated or lowly concentrated? For example: H2CO3, H+, HCO3-, CO3(2- charge), is in order of highest concentration to lowest concentration, can you explain why it is that order? Thanks for your help :)
November 2, 2013 by K

Chemistry
Dr.Bob222, I've been attempting the problem I posted previously about the ferrous ammonium sulphate, but I'm having no luck. I'm having trouble with my balanced equation. Do you mind showing me how to do the balanced equation? Thank you
November 2, 2009 by rasuka_geo

For: Ms. Sue, Steve, Writeatecher, Dr.Bob222
Hi everyone i wrote in the heading. I just want ed to say thanks for all the help you give me. I know sometimes I may get on your nerves or be annoying, and I just wanted to say sorry. Also thank you once agian for all the help.
October 31, 2012 by Jman

chemistry (Dr.Bob222)
In a reaction, if the concentration decreases faster, that means the reaction has a larger rate constant, and a faster reaction, and a shorter half-life. Is that a correct statement? If not, please correct me, thanks for your help :)
October 2, 2013 by K

math (conversion)
how do you conver ug/ml to ug/ul? There are 1,000 uL in 1 mL. So 1500 ug/mL = 1.500 ug/uL or in detail-- 1500 ug/mL x 1 mL/1,000 uL = 1.500 ug/uL. Thank you Dr. Bob222
February 6, 2007 by James

Dr Bob222 !!!! Chemistry
Cyclohexane is composed of 85.6 % C and 14.4% H. when it is mixed in the proper ratio with oxygen, it can be used as an anesthetic. At 755 mmHg, and 25 degrees Celcius, it has a density of 2.05 g/L. what is the molar mass of cyclohexane and its molecular formula? The way i ...
October 15, 2006 by Anonymous

Dr Bob222
Can you help me with this please - Temp - 650 Pressure - 690mm Hg mass - 0.927g volume - 194cm3 How do I calculate the volume of the gas at a different temp? & at a different pressure? You can do this two ways. The simplest is P1V2/T1 = P2V2/T2
February 27, 2007 by bex

chemistry "Dr. Bob222" Guidance Request
The lethal inhalation dose of Sarin for a 200lb person has been determined to be 0.0015 mg. Determine the LD50 of Sarin that researchers used to calculate this lethal inhalation dose. 1.4 x 10-4 mg/kg 0.16 x 10-4 mg/kg 1.8 x 10-5 mg/kg 0.00023 mg/kg
December 15, 2012 by Cameron

chemistry
why are they shaped liked this 1)BF4- is a tetrahedral molecule 2)SF3+ is a Trigonal pyramidal molecule 3)ICI4- IS A SQUARE PLANER molecule 4IF5 IS A SQUARE pyramidal molecule 5)PF5 IS A TRIGNAL BIPYRAMIDAl molecule help Dr bob222
December 17, 2011 by Anonymous

chemistry
using VSEPR THEORY explain why 1)BF4- is a tetrahedral molecule 2)SF3+ is a Trigonal pyramidal molecule 3)ICI4- IS A SQUARE PLANER molecule 4IF5 IS A SQUARE pyramidal molecule 5)PF5 IS A TRIGNAL BIPYRAMIDAl molecule help Dr bob222
December 16, 2011 by rebecca

chemistry
Dr.Bob222: I attempted to solve the problem numerous times but keep ending up with the wrong answer. If you would be kind enough to show me the steps I would appreciate it. I'll pose the question once more: The volume of a gas at 24C and 0.21 atm is 36 mL. What volume will ...
February 15, 2012 by Daddy

chemistry
Q1) For the reaction, A to B, Delta H= +11.00 kJ mol-1 and Keq is 12.50 Calculate i) delta G and ii) delta S at 25 C (degrees celcius) 0 C degrees celcius = 273.15 K; R = 8.314 J K-1 mol-1] PLease help dr bob222
February 16, 2012 by jenny

(23.Chemistry - Science (Dr. Bob222)
An electrochemical battery made from Sn and Cu electrodes under standard conditions shows an initial voltage of V= 1.1 V. If the concentration of both Cu2+ and Sn2+ solutions is increased to 2 M from 1 M, the observed voltage will: (Hint: use the Nernst equation) A. increase ...
May 8, 2014 by Ana

Chemistry - Science (Dr. Bob222)
At 25 degree C, a student adds 0.400 g of solid phosphoric acid to a beaker containing 500.0ml of water. After the solid is completely dissolved the student adds 20.0ml of a 0.995M sodium hydroxide. What is the pOH of the solution in the beaker?
April 13, 2014 by Adrik

chemistry
A 1.325 g sample of an unknown vapor occupies 386 mL at 114 celsius and 946 mmHg. The simplest formula of the compound is NO2. What is the molecular formula of the compound? (I have N2O4, is this correct and if not, why not? We never went over this type of question in class! ...
October 20, 2010 by lavonne

Chemistry
Dr. Bob222, Please see my additional posts on Jan 20 at 2:26pm and Jan 21 at 12:33 am. This is in reference to the redox reactions: 1) Fe goes from +2 to +3, and S goes from -2 to +6. They both appear to be oxidized because they increased. Is it possible that both can oxidize...
January 21, 2013 by Sushmitha

Chemistry (Dr.Bob222)
The generic equation: Base− + H2O -> HBase+ OH− can be used to account for the pH of which salt? 1)CaI2 2)NH3 3)KCN 4)Al(NO3)3 5)NaCl Ok, so I know NH3, won't work because it is not a salt. The answer is KCN, but I don't understand why, could you explain, why ...
November 2, 2013 by K

Chemistry - Science (Dr. Bob222)
The following reaction has a positive value of ΔG. 2H2O(g) → 2H2(g) + O2(g) Which of the following statements must be true? A. The reaction is slow. B. The reaction will not occur. That is, when H2O(g) is introduced into a flask, no O2 or H2 will form even over a ...
May 7, 2014 by Ana

For Dr.Bob222
I posted a question under First Amendment, would you look at the question and give your opinion? I'm not finding it Carrie. I Posted the question under first amendment question I will pass since government is not my field.
January 25, 2007 by Carrie

(12)Chemistry - Science (Dr. Bob222)
Calculate delta E for a process in which 88.0 g of nitrous oxide gas (N2O) is cooled from 165 ˚C to 65 ˚C at a constant pressure of 5.00 atm. The molecular weight of nitrous oxide is 44.02 g/mol, and its heat capacity at constant pressure, Cp, is 38.70 J/molK. A) - ...
May 8, 2014 by Ana

chemistry
. Compound C (MW = 550) is provided at a concentration of 25g/100mL. 1mL is taken and compound D is to be added (MW = 1025, concentration = 75mM) to give a final ratio of compound C:D of 4:1 moles ratio. What volume of compound D is to be added? ***Dr BOB222 THE 4:1 RATIO IS ...
December 11, 2011 by Bob

(11) Chemistry - Science (Dr. Bob222)
In the following hypothetical reaction A + B → C + D, the equilibrium constant, Keq is less than 1.0 at 25C and decreases by 35% on changing the temperature to 45C. What must be true according to this information? A. The ΔH for the reaction is negative. B. The...
May 7, 2014 by Ana

Science. plz help!!
What is the physical and chemical characteristics of the element neon? p.s- a really need help i'm not joking. oh yeah and thank you for your time! I think I answered this last night but it may not have been your question. Anyway, go to www.webelements.com and click on element...
November 13, 2006 by Vicky

Chemistry (Dr.Bob222)
The half-life of P-32 is 14 days. How long after a sample is delivered can a laboratory wait to use a sample in an experiment if they need at least 10 percent of the original radioactivity? I need help on how to set up this problem. What is the general equation to use for a ...
November 7, 2013 by K

Chemistry - Science (Dr. Bob222)
Use the following information to answer this question: Cu+(aq) + e- → Cu(s) E = 0.521V Cu2+ (aq) + e- → Cu+ (aq) E = 0.153 V. Given these half cell reactions, an aqueous solution of Cu+ ion in the absence of O2(g) : A. will be thermodynamically stable B. will ...
May 3, 2014 by Ana

Chem202 - for DrBob222
Dr. Bob222: There is a problem you answered .100M HClO2 titrated with .080M NaOH I can work the problem many times but I am getting 7.30pH and the answer says 7.38 using quad. I used quad and still get 7.30. I also do know how you go from the neutralization reaction of HClO2...
May 26, 2013 by Steve

11th grade math algebra 2 trig
Dr. Bob222 Iam sorry for my improper use of grammar. (not intended in a smart alike way.) you are buying beads and string to make a necklace. The string coast $1.50; A pack of 10 decorative beads costs $0.50; And a pack of 25 plain beads costs $0.75. You can only spend $7.00 ...
October 9, 2008 by Nick

chemistry - (Dr. Bob222)
A student attempted to synthesize malonic acid which has a molecular weight of 104 g/mol by the same method used to synthesize aspirin. A titration was performed to find the equivalent weight. 0.125 g of malonic acid product was used for a titration that required 24 mL of 0.10...
April 21, 2014 by Ana

chemistry (Dr.Bob222)
Do serial dilutions start out as saturated solutions?, Meaning when it starts out ppt forms, but there is a point where ppt stops forming, so when the ppt stops forming does that mean it is representing a saturated solution, and that when the ppt is not forming the solution ...
November 25, 2013 by K

chemistry
operating conditions 250-300 celcius and 50-100 atmospheres are consistent with the aims of achieving a high equilibrium yield of methanol and a high rate of production. noting any conflicts, explain the role of a copper catalyst noting how its presence helps with the conflict...
March 20, 2007 by c

Dr. Bob222 G-Chem
I agree with 0.0918 mols C and 0.137 mols H but not the formula. 0.137/0.0918 = about 1.5; is that C2H3? And the balanced equation is 4C2H3 + 11O2 ==> 8CO2 + 6H2O I've not heard of C2H3? Okay, I have never heard ofC2H3 as well, so I had to take the number of moles that I ...
February 6, 2013 by Devron

Chemistry - Science (Dr. Bob222)
Hydrazine is used as a rocket fuel because its reaction with oxygen is extremely exothermic: N2H4(liquid) + O2(g)  N2(g) + 2H2O(liquid) ΔH(reaction) = -615 kJ mol-1 What is the enthalpy of this reaction if water were produced in the gaseous rather than the liquid ...
May 8, 2014 by Ana

(1-11) Chemistry - Science (Dr. Bob222)
Liquid chloroform (CHCl3) is placed in a closed container and allowed to equilibrate with chloroform vapor. With the temperature held constant, additional chloroform is introduced into the system, and the vapor-liquid equilibrium is reestablished. Following this, the ...
May 10, 2014 by Ana

Chem 212
To treat a burn on your hand, you decide to place an ice cube on the burned skin. The mass of the ice cube is 16.1 g, and its initial temperature is -13.3 C. The water resulting from the melted ice reaches the temperature of your skin, 31.3 C. How much heat is absorbed by ...
February 19, 2013 by 1231az

chemistry
Hy Dr Bob222 this will be the last time I will bother you about this type of question. Can you please tell what I am doing wrong? This is the best answer I could come up with: Question: Strychnine, C21H22N2O2(aq) is a weak base but a powerful poison. Calculate the pH of a 0....
April 8, 2008 by Kelsy

For Dr.Bob222 (chem work)
What is the pH of a solution of 120 ml 0.15M acetic acid to which we add 30mL 0.2M NaOH? CAN YOU CHECK MY WORK PLEASE? 0.15 mol/L * 0.12 L = 0.018 mol acetic acid 0.2 mol/L * 0.03 L = 0.006 mol NaOH 0.018 - 0.006 = 0.012 mol of acetic acid in excess pH = pKa + log (acid/base) ...
August 27, 2007 by Gulzaman

Dr.Bob222
this is all my work so far on the limiting reagent problem I asked about yesterday about Calcium nitrate and ammonium fluoride.... 28.42g/164.1= .17318 mol Ca(NO3)2 29.6g/37.042=.79909 mol (NH4)F (1mol Ca(NO3)2 /.17318) x (2mol (NH4)F/x)=.34636 (2 mol (NH4)F/.79909)x(1 mol Ca(...
October 27, 2009 by Brittany

Organic Chemistry
Does anybody know of a website that explains organic nomenclature ? ...something along the lines "organic nomencluture for Dummies" would be great :-) I'm stuggling to underatand "Z-3-Bromo-6-methyloct-3-ene" let alone draw it ! Here is a site that might just be what you are ...
March 12, 2007 by WeatherGirl

(2-8) Chemistry - Science (Dr. Bob222)
Which of the following statements is correct? A) The internal energy of a system increases when more work is done by the system than the heat that flows into the system. B) The system does work on the surroundings when an ideal gas expands against a constant external pressure...
May 11, 2014 by Ana

general
what is G.P.A. in college, and how is it determined? and more information about academic standing. Write a paragraph. It varies depending on the college. Variables include: major, pass/fail courses. You need to see the policies for particular institutions. https://my.unsw.edu....
December 3, 2006 by deek

Chemistry/ Dr.Bob222
DrBob222 I am beginning to understand about balancing equations well, thanks to your help, but there are still some other things, which I am having a hard time figuring out. Complete and balance the following chemical reactions between an acid and a metal. A) HBR + Mg -> ...
July 13, 2010 by Derrick

chemistry - Can you please check
Calculate the amount (g) of each of the following salts that need to be added to a 200 mL volumetric flask to produce a 2 M solution of S. CaSO4 (NH4)2SO4 Fe2(SO4)3 Dr. BOB222, Could you please check the following? Thank you. CaSO4: moles x atomic mass = .0400 x 32.066 amu = ...
January 23, 2013 by Sejul

Chemistry - Science (Dr. Bob222)
Nitrogen gas has values of Cv and Cp of 20.8 and 29.1 J K-1 mol-1, respectively. When a certain amount of nitrogen is heated at constant pressure, what fraction of the heat Q is used to increase the internal energy of the gas, and how is the remaining energy used? A) 3/2 of Q ...
May 8, 2014 by Ana

Chemistry - Science (Dr. Bob222)
A student wanted to determine the amount of copper in a sample of copper ore. The student dissolved a 2.500 0.001 g piece of copper ore in about 75 mL of nitric acid; then, a complexing agent was added. The student transferred this solution to a volumetric flask and used de-...
March 25, 2014 by Anonymous

chemistry
TO DR.BOB222 hi i have a question. It's regarding a electrolytic cells. This lab has already been posted but i wanted to show you what i have so maybe you can check it for me. question: what is the mass of tin produced? what is the theoretical mass of tin that should have been...
April 18, 2008 by samantha

Chemistry...Attn DrBob222
Thanks for your earlier thoughts. Am still working on the problem and would like to know if you have any thoughts on my approach below: If I have a set of data that gives the apparent partition coefficient as a function of pH, over a range of pH 2-10, how do I calculate the Ka...
March 12, 2010 by Renee

chemistry
Calculate the pH at the point in the titration of 25.00 mL 0.108 M HNO2 at which 10.00 mL 0.162 M NaOH have been added. For HNO2, Ka=5.1 x 10^-4 and: HNO2 + OH- -----> H2O + NO2- I know that HNO2 is a weak acid and NaOH is a strong base. Help given to me so far from Dr. ...
October 4, 2011 by Holly

Belinda, Math
I aked the instructor about that problem that looked like this: (w-(1)/(4))^2 and he said that what i thought was right. which was : the answer:w^2-(1)/(2)w+(1)/(6) Yes, that's right. I just thought your way of getting the answer was more complicated than it could have been. ...
January 25, 2007 by Jasmine20

Chemistry
My question is what is the molar mass of 1.00 mol of Li? Can you explain in detail and I have another question: What is the molar mass od 1.00 mol of Ag but if you help me with the first question, then can you just tell me to the other by myself so I can see if I did it right ...
October 16, 2006 by Cupcake

chemistry
Which solution would CaC2O4 be most soluble in? Na2C2O4 NaHC2O4 H2C2O4 NaCl HCl I due to common ions i think it would be one of the first three and i think it is Na2C2O4 because the other 2 have Hydrogen. Is it Na2C2O4? No, the common ions work just the other way; CaC2O4 will ...
April 7, 2007 by jacob

math
SOMEBODY PLEASE HELP ME!!!I CANT FIND TESSELATION.PLEASE HELP. The word is tessellation. If you had read my response to your original question you would have known how to spell it. Go to www.google.com, type in anything close and it will ask you if you meant tessellation. ...
October 15, 2006 by vaneesa

Physics
well, we tried searching up simple physics equations on google, as dr. bob222 suggested, but we found problems that were way out odf our range. we are looking for problems similar to this. --- Suzan does not remember which one of the following equations --- t=2pi l/g or t=...
July 8, 2008 by Shivangi & Jennily

Chemistry - Science (Dr. Bob222)
Posted by Ana on Saturday, May 3, 2014 at 11:23am. A zinc-copper battery is constructed as follows (standard reduction potentials given below): Zn | Zn2+ (0.10 M) || Cu2+ (2.50 M) | Cu Zn2+ + 2 e- → Zn(s) E = -0.76 V Cu2+ + 2 e- → Cu(s) E = 0.34 V The mass of ...
May 5, 2014 by Ana

GK or Dr.Bob222...Chemistry please help...
Please refer to the previous post Chemistry Help Please. Moles of S203^2- = (molarity)(volume): =(0.032400 mol/L)(0.053 litres S203^2-) = 0.03240 moles S203^2- Posted by DrBob222 on Wednesday, October 22, 2008 at 9:37pm in response to GK..please check...Chemistry Help Please I...
October 23, 2008 by Sara

Managerial Economics
I need assistance with the following question: A researcher estimated that the price elasticity of demand for automobiles in the United States is -1.2, while the income elasticity of demand is 3.0. Next year, U.S. auto makers intend to increase the average price of automobiles...
November 8, 2006 by Talia

Chemistry
Need to write a balanced chemical equation for the reaction between hydrogen selenide and tin. I know that the hydrogen selenide decomposes producing solid tin selenide and hydrogen gas but how would I balance that in the equation. Any help gratefully recieved. I can write and...
January 7, 2007 by Mac

chemistry - Dr.Bob222 please help
Hi Everyone, Anyone want to try giving these a shot? The right electrode in a cell is a piece of copper immersed in a 1.00 L solution of 0.0701 F copper sulfate. The left electrode is a galvanized nail (i.e., an iron nail that is completely coated with a layer of zinc), ...
November 7, 2006 by ajones51

Dr.Bob222- IChemical formulas&Reactions
When aqueous copper(II)chloride reacts with aqueous ammonium phosphate, soluble ammonium chloride forms and copper(II) phosphate precipitates out of solution. 1. Write the balanced molecular equationfor this reaction. 2. Write the balanced complete ionic equation for this ...
January 3, 2007 by chrissy

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