Where did you get 5E-5. Is this how you set it up? 0.01 x 0.05 = 5E-4 If so, is it supposed to be 5E-4 instead of 5E-5? What is the equilibrium constant for a weak acid HA that dissociates 1% at an initial concentration of 0.05 M according to the following balanced chemical ...
DrBob222 I am kind of stuck with the balancing stuff, and I already had send the post, did you not read it?
Hey does anyone know when DrBob222 comes on here, cause I have a lot of chemistry questions which I need him to check. Thanks.
Thanks a lot I get it now!!!!!! From Adam To DrBob222
DrBob222 do you know anything about Heredity and Punnet Squares?
DrBob222 You are an amazing person! I have received more help from you the past two days that I have this whole semester from my instructor! You have an amazing gift of breaking things down to understand completely! Where are you from? Do you get paid for this somehow? look me...
DrBob222 please check my physics question posted at 8:55pm. The subject is drwl please check. I am not getting a response from drwl. Thanks! Mary DrWLS is not on right now. My physics is too poor to trust my answers. Bob Pursley is smarter than I am; he does physics, math, and...
Drbob222, even if you just tell me that there is an answer to the following problem then i know that there is an answer because i've tried many ways and i can't get x alone. -4(2x-3) = -8x +5 Is there an actual answer for this one? No. There is no answer, the question is ...
solve Ka for HX => H^+ + X^- given 0.1M LiX at pH=8.9 Chemistry - DrBob222, Tuesday, March 30, 2010 at 6:32pm LiX(aq) ==> Li^+(aq) + X^-(aq) X^- is a base and hydrolyzes in water to X^- + HOH ==> HX + OH^- Make an ICE chart and substitute into the following: Kb = (Kw/...
I'm sorry the problems i posted had a couple of errors how i posted it here they are: Posted by DrBob222 on Friday, November 24, 2006 at 6:19pm in response to Math. Thanks for showing your work. It helps us to know where you are having trouble. #4. [25/ (2^3-3)]*2 the star two...
my original question was: how do i figure this out?? How much heat does your body lose when 2.46 g of sweat evaporates from your skin at 25°C? chem - DrBob222, Tuesday, February 22, 2011 at 10:52pm q = mass water x delta Hvaporization. chem - Rebekah, Wednesday, February 23, ...
I got an answer of -1.34 x 10^3 KJ/mol. A 10.00 mL aliquot of 0.100 M NaOH is added to 15.00 mL of 0.100M HCl in a coffee cup calorimeter. The initial temperature of the two dilute liquids were both 25.0 degrees C and the final temperature of the mixture was found to be 37.8 ...
solve Ka for HX => H^+ + X^- given 0.1M LiX at pH=8.9 Chemistry - DrBob222, Tuesday, March 30, 2010 at 6:32pm LiX(aq) ==> Li^+(aq) + X^-(aq) Question for DrBob222 - is the X^- value in the ICE calculations 0.1 from the initial LiX 0.1M? X^- is a base and hydrolyzes in ...
Calculate the pH of an aqueous solution of 0.15 M potassium carbonate. I know that pH = -log(H30+) but I am not sure how to start this problem. Chemistry(Please help) - DrBob222, Saturday, April 14, 2012 at 11:09pm Hydrolyze the CO3^2-. CO3^- + HOH ==> HCO3^- + OH^- Do an ...
DrBob222, I don't know how to solve this problem either. And yes, this is the question for this problem. I even double check it. Please help. Chloroform (CHCL3) has a normal boiling point of 61 'C and an enthalpy of vaporization of 29.24 kJ/mol. What is the value of delta Gvap...
so i posted this question yesturday and got some help. which is the stuff below. can you look at the last thing i said which was the answer i got by doing what DrBob222 said to do and tell me if its correct.(the question is the first section) thanks chem - hannah, A salt ...
Strychnine, C21H22N2)2(aq) is a weak base but a powerful poison. Calculate the pH of a 0.001 mol/L solution of strychnine. The Kb of strychnine is 1.0 x 10^-6 DrBob222, I am planning on obtaining a pHD in about nine years:P Can you give me some advice on how to be that 1% of ...
What is 14/4 as an integer?
is the answer 64.48$
thank you so very much
Please help me on my question thanks
If you don't mind me asking, How are you so smart, and how old are you?
I don't get how to get N, please show me cause I don't understand
What is the formula for 2-bromomethylpropane ?
Thank you very much. I appreciate it a lot.
THANKS so much for all of your quick and useful help!
thankyou for your help its helped alot.you are a star!
Drbob222 that does not help. got anything else up ur sleeve?
I got 206.67 g Fe, DrBob222
Please check my post again
I have to calculate the concentration of I2 produced (# of moles of I2 produced / L) based on the stoichiometric ratio in the following equation. 2S2O3^2- + I2 -> 2I^- + S4O6^2- Chemistry(Urgent, please help) - DrBob222, Sunday, February 26, 2012 at 9:47pm If you know the ...
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 -> ...
If a wave has a period of .02 seconds and a speed of 4 m/s, what is its wavelength? .08 m
I reponded back to you on my science helpers post.
DrBob222 - it says my answer should be a number.
What is the [H3O+] of a solution with [OH-] = 6.3 × 10-4 M? A. 6.3 × 10-18 M B. 10.80 M C. 6.3 × 10-4 M D. 1.6 × 10-11 M DrBob222 can you help me with this question please?
Convert a pressure of 23.8 in. Hg into kilopascal. Ok so I looked up kilopascal and it Said 1 Kpa = 1000 pa So I began to set it up like this 23.8 / 29.2 x1000 am I correct Chemistry - DrBob222, Thursday, October 13, 2011 at 1:48pm I don't think that will get it. I would go ...
Is the answer for part c 0.91? A 1.0 L ball containing Ar at 5 atm is connected to a 10.0 L ball containing N2 at 2atm. A)Calculate the partial pressures and mole fractions of Ar and N2 after the valve is opened and the gases are allowed to mix (they fill the balls on both ...
The Doppler effect is a change in the ______of a sound. pitch
Are you done helping me? Sorry, to bugg you i just reall need the help.
Thank you sir for helping me out with those chemistry problems.
Can you please help me with some questions I have on my Chemistry lab?
When is there a need to determine G? A. When H > 0 and S = 0 B. When H > 0 and S > 0 C. When H = 0 and S < 0 D. When H > 0 and S < 0 P.S. there are triangles before the G, H, and S.
how do I calculate pressure exerted by H2 in a Mg and HCl reaction? (weighing by redox)
DrBob222 please help me answer the question that I posted pleaseee, pleaseeee
Is DrBob222 available tonight? Please let me know, I need some chem help.
DrBob222- Is STP = to 273K? If so, would i use P1V1/T1 = P2V2/T2??
Is the relationship between delta G and Temperature inverse or direct?
Hi Dr. Bob would you please tell me what D rpresents? Thank you! What is the reactant, products, and what compounds is it? Is it H2O, O2, or what? What are the transition molecules? Help please. Do as below to get to the image. I couldn't put the URL in and it isn't my website...
Sorry , I thought it went through. What i want to be corrected is the following. (30)
I so need help please tell me some obscure facts about spain
can you please have a moment to look at my other previous posts, thanks a lot:-)
Just WHO IS DRBOB222? AND WHY ARE YOU SO AMAZING? PLEASE TELL US MORE ABOUT YOURSELF!
to DrBob222 wouldn't it be like this then 4.86L/12.75kg*1000cm^3/1L*(1kg/1000g)^3
to drbob222 ok, the pka (hclo) = 7.54 the ph = 7.35 this problem was under "preparing a buffer" section
DrBob222 No. 0.30 isn't the correct answer either. I'm going to ask my prof about it tomorrow.
What happens when a wave reaches the boundary of a new media? it would reflect back.
For incomplete cancellation to occur, opposite pulses must have. equal displacements
As a sound source moves away from a stationary observer, the number of waves will. decrease
DrBob222 - for molar mass do you use significant figures? If so would the answer be 0.05 (3.55/65.39)3.55 has 3 SF's correct?
DrBob222. when you move ice from zero to final T. Do you add 100 cal.?
Hey DrBoB222 I was wondering if you could help me with that problem just a little bit ago again?
I know I posted this but you didn't answer! Please help!!!! Consider the following reaction at 298 K: C(graphite) +2Cl2 (g) -----> CCl4(l) Calculate the following quantities. Delta H: -139 kJ/mol deltaS(sys)=? J/mol*K deltaS(surr)=? J/mol*K deltaS(univ)=? J/mol*K My answer ...
The following thermodynamic data was obtained for an unknown compound. Delta Hvap = 31.3 kj/mol and Delta S Vap= 79.7 kj/mol .Calculate the normal boiling point of this compound in Celcius.. Thank you! Chemistry - DrBob222, Tuesday, April 30, 2013 at 12:31am dG = dHvap - ...
I really want to know what this symbol means ^. I haven't learned about it at all. Does it mean squared or something?
to drbob222: the book says that the naclo grams are equal to 2.4. how did they come up with that from the Henderson hesselbalch equation?
For the medium to remain undisturbed as two pulses pass the same point, they must have. different amplitudes
what does air pressute do to the freezing, melting ad boiling point *Note to DrBob222: If you are going to answer this, please , no links
(This homework question has been removed due to a copyright claim submitted by K12 Inc.)
Can you check my previous postage I'd reply already. Thank you done below What are about the other messages are they okay too. I think I just finished with all of them.
You just answered my previous half-life question, and I was curious how to find the value of k. You said that k = 0.693/t1/2 , but how do you evaluate t sub1/2?
Why is it important in gravimetric analysis to add an excess amount of precipitating ions to a solution containing an analyte
What is the equilibrium constant for a weak acid HA that dissociates 1% at an initial concentration of 0.05 M according to the following balanced chemical equation? HA <----> H+ + A-
Calculate the standard free-energy change for the following reaction at 25 C degrees. 2Au^3+(aq)+3Ni(s) <-- --> 2Au(s)+3Ni^2+(aq) Ni2+(aq) + 2e- -> Ni(s) E=-0.26 Au3+(aq) + 3e- -> Au(s) E=+1.498 G= ? KJ Would it be G=1.758? •Chemistry - DrBob222, Sunday, March 31...
A student fails to fill the cuvette 2/3 full with the reaction mixture ( CV+ and OH-). What effect does this error have on the measured absorbance values? Thank you :)
DrBob222 - can you set up the equation for the volume problem, i don't have a clue... Is this Charles Law? I know how to change C to K you add 273, but I don't know what figures go where in this formula PV=nRT......
What are the relative rates of reaction of primary, secondary and tertiary alkyly halides in an SN1 substitution? Explain the reason for your answer? Thank you so much?
I really need help on these chemistry problems. Can you please help me work them. Please?
for a thermodynamics lab, I have to graph the ln K vs. 1/T, so does the ln K go on the y-axis and the 1/T go on the x-axis?
Shaking a towel up and down would create what type of wave in the towel? surface
I already asked Drbob222 for a substance that i cantake to school wich contains an aromatic compund, I'm not suppose to buy because it must be at home. please help me:0
True/False The medium determines the speed through which most mechanical waves will travel. True
Dear DrBob222 !!! Would you please help me answers the question that I posted. I really don't understand and need help! Please, Thanks
A .326L container holds 0.146g of Ne and an unknown amount of Ar at 30C and the total pressure is 627 mmHg. Calculate the moles of Ar present? (I have calculated temp 308K, pressure is 0.825 atm and moles of Ne are .007) Chem - DrBob222, Wednesday, March 3, 2010 at 3:25pm T is...
A certain compound contains carbon, hydrogen , and oxygen. When 1.00 grams of this compound are burned in oxygen gas 1.47 grams of CO2 and 0.600 grams of water are formed. When 2.75 grams of the compound are dissolved in 10.0 grams of water the resulting solution freezes at...
A wave created when two different waves meet will have an amplitude greater than the individual waves because of. constructive interference
Can you please check my previous science post. As of right now, you are the only science teacher on this site--which is why I am pleading you to. Thank you very much:-)
How much water is needed to dilute 25.0 ml of 0.357 mol/L hydrochloric acid to 0.246 mol/L I got 17.2 is that correct
What is the reason for considering N2 has a boiling point lower than O2,because of its low molecular mass. Just curious about that old reason...
identify the following formulas as acids, bases or salts: HCH3COO NaCL H2CO3 C6H8)7 Mg(OH) NaOH KBr Sr(OH)2 HNO3 please help really urgent :) thanks :)
Although I vaguely see DrBob222's concept, I still need some help in the set up. Thank you. A 10 lb. frozen boneless roast needs to be thawed and baked to a temperature of 200 degrees F. The storage freezer maintains a temperature of -10 degrees F. Pork changes from solid to a...
I posted this question already but you never replied back :( Consider the following reaction at 298 K: C(graphite) +2Cl2 (g) -----> CCl4(l) Calculate the following quantities. Delta H: -139 kJ/mol deltaS(sys)=? J/mol*K deltaS(surr)=? J/mol*K deltaS(univ)=? J/mol*K My answer...
Please I posted a chemistry question but I havent gotten any answer back please help me, sorry for having so little patience answered below.
THANK YOU DR BOB YOU ARE SO AWESOME!!!
Hi I have a follow up to a question that was answered previously. New question: So when the HPO4(2-) reacts with the NaOH, will the equation be this?: HPO4^(2-) + NaOH --> H2O + NaPO4(2-) But how do I write the equation for the H2PO4^- and HCl? H2PO4^- + HCl --> Here is ...
1) The Ka for acetic acid is 1.8e-5. What is the pH of a 3.18M solution of this acid? I did 1.8e-5 = x^2/3.18 x=sqrt 1.8e-5 X 3.18 = 7.56e-3 pH=-log(7.56e-3) = 2.12 The pH is 2.12 2) At 25 degrees celsius, the pH of a 1.75M NaCN solution (the Ka for HCN is 4.0e-10) is ? 4.0e-...
Regarding my question on display.cgi?id=1496901710(I can't post URLs) Can we apply the formula PM=dRT seperately to the systems before and after being heated,and solve this one?
You asked me to show my work for one of my questions a few minutes ago and i need you to verify my work because you said my answer was wrong
The unique rate for the combustion of ethane is 0.44 M/s (a) what is the rate that oxygen reacts? (b) what is the rate of formation of water molecules?