Thursday
April 24, 2014

Search: CHEM AP please help!!

Number of results: 50,605

chem- drbob222 please help
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 25C? chem - DrBob222, Tuesday, February 22, 2011 at 10:52pm q = mass water x delta Hvaporization. chem - Rebekah, Wednesday, February 23, ...
Wednesday, February 23, 2011 at 5:49pm by Rebekah

AP CHEM
A secondary alcohol results from the attachment of a hydroxy group to which carbon atom? C | <---GIVEN STRUCTURE C1-C2-C3-C4 A) C1 B) C2 C)C3 D)C4 Answer is C! I have to explain why, but the teacher never taught us anything about organic chem. So please explain!
Friday, April 5, 2013 at 2:52pm by Anonymous

chem
What is another name for cardamist? Please write the formula and a link to its structure. See http://antoine.frostburg.edu/chem/senese/101/consumer/faq/what-is-cardamist.shtml
Sunday, September 4, 2005 at 5:04pm by Nisar

chem help
im doing a graph for chem lab with excel. my classmate created a graph with these coordinates: X: 3.50 X10^-3 3.14X10^-3 3.28X10^-3 Y: -11.7 -8.96 -9.75 They got R2=0.998 but i got y = -3074.9x R = 0.6291 why is it wrong. im desperate please help! screen shot of my graph: ...
Saturday, October 23, 2010 at 11:05pm by ben

chem/science
Please predict what will happen. Im not very good in chem. Iron metal and pb(NO3) Lead metal and Mg(9NO3)2 Copper metal and AL(NO3)3 Lead metal and AgNO3
Thursday, April 18, 2013 at 8:44pm by jim

chem -repost for bobpursley
i don't know how to solve this. looked through all my notes but i'm not sure what kind of formula i am to use or if i even need one! please help me to understand the theory behind this: "calculate the work need to make room for the products in the combustion of S8(s) to SO2(g...
Sunday, April 17, 2011 at 8:53pm by please, help me

Chem
Are: Ba(NO3)2, Ti)2, MgI2, and Ca(CH3COO)2 soluble or insoluble in H2O @ 25degrees C? Here is a site that lists the solubility rules. You should know this table; eventually you will want to know it so well that it is memorized. If you still have questions after viewing this ...
Friday, October 20, 2006 at 1:41pm by K

Chem Check Please!!!
Using standard thermodynamic data from Appendix L of your text, calculate the equilibrium constant at 298 K for the following chemical reaction: CO(g) + H2O(l) CO2(g) + H2(g). Show work please! Thank you!!!
Sunday, March 16, 2014 at 11:20pm by Layla

chem
i don't get this at all can you please show me how to do this problem: a sample of oxygen occupies 10.0 L under a pressure of 105 kPa. at what pressure will it occupy 13.4 L if the temperature does not change. please help me set it up
Thursday, May 14, 2009 at 6:33pm by melissa

chem can u check answer please
the solubility of silver sulfate in water is 0.223%(w/v) at 35 degrees celsius.calculate the solubility product of this salt at this temp. I got 1.46 X 10^-6 M is this right please thanks Andy
Sunday, May 23, 2010 at 10:33pm by Andy

chem
Please help me balance this equation: I just can't get it right. Do you have any strategy you use to solve such equation balancing if so please help me. Ba(ClO3)2(aq)+ Na3PO4(aq)-> Ba3(PO4)2(s)+NaClO3(aq) Thanks alot!!:)
Monday, March 18, 2013 at 5:34pm by katlyn

chem
Dr Bob please answer below
Monday, January 5, 2009 at 7:43pm by lyne

O-CHEM
Do you expect acetaminophen to be soluble in water? why or why not? please help... thanks
Tuesday, February 3, 2009 at 11:50pm by Nina

O-CHEM
Do you expect acetaminophen to be soluble in 1.0 M NaOH? why or why not? please help... thanks
Tuesday, February 3, 2009 at 11:52pm by Nina

chem. AP
Please help? How would you convert 300 torr to mm hg?
Monday, February 15, 2010 at 7:32pm by Cindy

chem
how many atoms of C are in 2 moles of sucrose C12H22O11? please help
Wednesday, March 17, 2010 at 12:28pm by suzie

Chem
cr(s)--->Cr^3(aq)+3e- and Pb2+(aq)+2e---->Pb(s) write a balanced equation Please help thanks
Sunday, May 5, 2013 at 5:04pm by Jess

chem
for 2Al2O3----> 4Al(s) + 3O2 the question is what is the heat change for the formation of 1 mol of aluminum oxide from its elements? Al2O3:-1676.0 O2:0.0 Can someone please explain how to complete this problem step by step please??
Tuesday, January 22, 2013 at 6:08pm by sara

chem
Ionic bonds and covalent bonds, which one is the stronger. My present teacher said that covalent bond is the strongest one. I learned ionic interaction is the strongest and many chem. books say so. Now i am confused. Is my present teacher right. Please explain this for me, and...
Tuesday, October 5, 2010 at 9:35pm by bun

Chem
The experiment is about titration of vinegar with NaOH. Before I start titration, I need to calculate how much of vinegar I will want to be using. I think I might use 50ml of distilled water to mix vinegar and I am gonna drop 3drops of phenolphthalein as indicator. Please help...
Sunday, October 10, 2010 at 1:54am by Kim

Chem Urgent!
I need help in balancing equation for NO2 + O2 -> NO + O3 Please help...
Saturday, March 15, 2008 at 6:51pm by Lily

college chem
PLEASE..Determine [OH-]of a solution that is 0.270 M in HCO3-...thanks
Friday, April 9, 2010 at 1:33pm by susy

chem
convert 8.00in^3 to ml please tell me how to solve this what are the steps ,
Wednesday, September 14, 2011 at 8:02pm by Anonymous

chem
calculate the PH of [OH-] = 4.510−3 M Please show how you work this problem.
Wednesday, January 18, 2012 at 6:59pm by john

chem please help
Find the number of moles of H2 in 1660mL H2 gas.
Wednesday, July 17, 2013 at 11:06pm by Anonymous

chem HELP PLEASE
how do i calculate a concentration ratio of oxidised to reduced cytochrome c Fe2+ to Fe3+ given at 25 C and pH7 E(mV) as 100 and absorbance at 550nm as 1.5 E is relative to standard hydrogen electrode i dont know how im supposed to calculate it from this data please help!!!
Thursday, February 18, 2010 at 9:47am by lu

chem please help
how do i calculate a concentration ratio of oxidised to reduced cytochrome c Fe2+ to Fe3+ given at 25 C and pH7 E(mV) as 100 and absorbance at 550nm as 1.5 E is relative to standard hydrogen electrode i dont know how im supposed to calculate it from this data please help!
Thursday, February 18, 2010 at 4:09pm by lu

chem HELP PLEASE its physics side of chem
given E, = l^2 h^2 / 2 m r^2 calculate energies for an electron localised to a circle of radius 2 x 10^-9 m for l = 0,1,2, draw pictures of three levels and calculate the relative populations of these levels at 300K i did the first bit but came out with, 0, 6.0249 x 10-6 J mol...
Tuesday, October 27, 2009 at 4:51pm by poppy

chem help please!
what is the formal charge for OMe and how many electrons would it donate?
Thursday, February 5, 2009 at 6:35pm by mary

Chemistry
Is DrBob222 available tonight? Please let me know, I need some chem help.
Monday, October 11, 2010 at 8:37pm by Karen

Chem ap
What happens to cell potential as temperature decreases? Please explain
Sunday, April 3, 2011 at 1:56am by boots

chem please..
are we exchanging force-carrying particles when we touch something?
Monday, February 24, 2014 at 9:04pm by Anonymous

CHEM AP please help!!
Using Heisenberg's uncertainty principle, calculate the uncertainty in the position of the following. a 1.32-mg mosquito moving at a speed of 1.61 m/s if the speed is known to within 0.01 m/s i tried every way and still cant get it..please someone help
Sunday, October 23, 2011 at 10:37pm by Karina

Chem help-please
At o degrees celcius, a 1.0-L flask contains 5.0 x 10^-2 mol N2, 1.5 x 10^2 mg O2 and 5.0 x 10^21 molecules of NH3. What is the p00artial pressure of each gasnand what is the total pressure in the flask? I need to understand how to calculate it, formula and how to get the ...
Friday, May 4, 2012 at 8:59pm by KL

Chem for final, please help!
How many moles of H+(aq) ions are present in 1.25 L of 0.75M Nitric Acid? A. 0.60 mol B. 0.75 mol C. 0.94 mol D. 1.7 mol E. 1.9 mol Please show me how to work this!
Tuesday, December 7, 2010 at 1:27pm by lavonne

chem
Can someone show me the structural formula (lewis diagram) for ethene??? Please
Wednesday, March 31, 2010 at 2:39pm by Stacey

Chem please help
Formulas for the covalent compounds: Diphosphorous monoxide Tetrasulfur hexaiodide
Thursday, February 23, 2012 at 9:54pm by Margearett

Chem
238U + 2H --> ________+ 2 1n 92 1 0 I don't know the answer that goes in the blank or how to figure it out. Please help me. Thanks
Sunday, March 11, 2012 at 11:31pm by Andretti

Chem Please Help
If a 2.30 M sample of A is heated to 500 K, what is the concentration of B at equilibrium? A<-> 2B Kc= 5.04x10^-6 at 500k
Tuesday, April 1, 2014 at 12:43am by Anonymous

Chem
This is a lab concerning activity serious of metals and calculation of electrode portentions... Complete the following: if there is NO reaction write NR: (They provided the reactants, my answer is the products) Iron(s) + copper sulfate(aq) → iron sulfate(aq) + copper(s) ...
Wednesday, March 28, 2007 at 9:16pm by Marisol

Simple Chem O2
What is O2 mean? Also what is oxygen gas the formula? Please could someone answer this?
Wednesday, June 2, 2010 at 9:21pm by A

chem (urgent)
Can someone please explain to me in simple terms what the eutectic point and temperature are?
Friday, September 16, 2011 at 12:03pm by laura

Chem 1A
Help please! How many moles of NaOH must be added to 1.0 L of 3.0 M HC2H3O2 to produce a solution buffered at each pH? 1) pH= 3.78 2) PH= 6.52
Thursday, March 15, 2012 at 10:01pm by Mackenzie

Chem! Please helpppp!!!!!
Consider the evaporation of methanol at 25.0 c: CH3OH(l)-- CH3OH(g) I figured out that Delta G is 4.3 kJ. Find the Delta G at 25 C under the following conditions: Pressure of CH3OH= 157mmHg, 103mmHg, 14mmHg thanks! please explain
Thursday, November 11, 2010 at 6:17pm by JP

chem
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 ...
Wednesday, November 10, 2010 at 4:18pm by hannah

Urgent for Chem!
need help in balancing equation for NO2 + O2 -> NO + O3 Please help it may look balance but it is not. This is a tricky one
Saturday, March 15, 2008 at 7:25pm by Anynamous

CHEM
can u rank the fallowing elements by increasing electronegativity: sulur, oxygen, neon, and aluminum. please help!
Sunday, January 24, 2010 at 12:21am by Jay

Chem 2
Calculate the solubility of silver chromate, Ag2CrO4- in 0.005M Na22Cr)4- Ksp=2.6X10-12 HELP PLEASE......
Friday, March 2, 2012 at 5:10pm by DebC

chem
if a car produces 81g of {\rm CO_2}, how many grams of {\rm O_2} are used up in the reaction? the complete chem reaction is C2H6O+3O2--->2CO2+3H2O
Friday, October 19, 2012 at 8:20am by tracy

Dr. Bob
Dr. Bob, can you please tell me if I did my chem questions right... they have been sitting down there all day and all i need is someone to check if they are right please and thank you
Tuesday, February 19, 2008 at 12:35am by Lauren

chem--please help me!!
when a 25.0 mL sample of an unknown acid was titrated with a 0.100 M NaOH solution. Determine Ka for the unknown acid. Volume NaOH = 12.5 mL; pH=3.80 please help me explain in details!!!
Saturday, October 30, 2010 at 2:29pm by Sue

CHEM
rank the fallowing elements by increasing atomic radius: carbon, aluminum, oxygen, potassium. please help!
Sunday, January 24, 2010 at 12:23am by Jay

please chem help
What is the ratio of the activities of Zn 2+ and Pb 2+ in a solution that is in equilibrium with respect to sphalerite and galena?disregard hydrolysis effect
Thursday, September 16, 2010 at 2:58am by moon

please chem help
What is the ratio of the activities of Zn 2+ and Pb 2+ in a solution that is in equilibrium with respect to sphalerite and galena?disregard hydrolysis effect
Thursday, September 16, 2010 at 3:00am by moon

please chem help
What is the ratio of the activities of Zn 2+ and Pb 2+ in a solution that is in equilibrium with respect to sphalerite and galena?disregard hydrolysis effect
Thursday, September 16, 2010 at 3:00am by moon

please chem help
What is the ratio of the activities of Zn 2+ and Pb 2+ in a solution that is in equilibrium with respect to sphalerite and galena?disregard hydrolysis effect
Thursday, September 16, 2010 at 3:00am by moon

Organic Chem
how would you make 300mL of toluene and hexane in a artion of 70:30 respectively? i dont un derstand please help
Tuesday, September 28, 2010 at 6:57pm by steph

Chem
A 50 ml sample of 0.025M AgNo3 is mixed with 15 ml of 0.04 M CrCl3. How many grams of AgCl will precipitate? Please show steps
Saturday, October 9, 2010 at 5:15pm by MAX

chem
How many moles of O are in 13.0 mol Fe(NO3)3? can you please find this using dymensional analysis and show me how you worked it? Thans
Wednesday, November 10, 2010 at 5:50pm by sara

chem please help !!!!
what might one do to verify that the global strain energy minimum has been identified for a compound?
Thursday, October 13, 2011 at 9:29pm by jon

College Chem 2
calculate the solunility of silver chromate, Ag2CrO4, in 0.005 M NA2CrO4- Ksp=2.6x10-12 Please help.....
Saturday, March 3, 2012 at 1:26pm by Deb

Chem Help!
I really need help with this question for my chem H.W. 1) On a summer day in Breckenridge, Colorado, the atmospheric pressure is 525 mm Hg. What is this air pressure in atmospheres? (round to the hundredths place) atm
Thursday, April 10, 2008 at 12:34pm by Lisa

Biology/Chem
Can someone please explain how I would write the equation for the hydrolysis of lactose using structural formulae? Thanks.
Tuesday, March 20, 2007 at 5:40pm by Confucious

chem help please
K= 6.9x10^10 which way does this dominate to right or left? for equilibrium constant? this is a hw problem i just dont understand
Thursday, December 6, 2007 at 7:53pm by alicia

Chem
which of the following is not soluble ? (1)sodium chromate (2)lead(II)iodide (3)lithium hydroxide (4)ammonium sulfate don't understand, please help.
Sunday, February 13, 2011 at 7:22pm by Jackson

CHEM, please help!
What pH buffer solution is needed to give a Ni2+ concentration of 2.5 x 10-3M in equilibrium with solid nickel hydroxide Ni(OH)2? Ksp = 6.0 x 10-16.
Sunday, March 18, 2012 at 10:47pm by Kate

To DrBob222(Please check Chem)
(This homework question has been removed due to a copyright claim submitted by K12 Inc.)
Thursday, June 21, 2012 at 11:34am by Liz

AP CHEM! PLEASE HELP
A sample consisting of various gases contains 2.6 10-6 mole fraction of radon. This gas at a total pressure of 37 atm is shaken with water at 30C. Calculate the molar concentration of radon in the water. Can somepne please provide a step by step instruction?
Monday, December 12, 2011 at 11:18pm by kanika

Chem- bobpursley
What mass of protons would be required to just neutralize the charge of 1.5 g of electrons? my teacher said .0015kg times 1e-/.00091e-27kg times 1pt/1e- times 1.67262e-27 over 1 p chem - bobpursley, Tuesday, September 21, 2010 at 6:48pm That is what I would do also. But I ...
Tuesday, September 21, 2010 at 8:39pm by Sara

MATH/CHEM PLEASE HELP!
Give the answer to the following calculation with the correct number of significant digits. Report your answer in scientific notation. (6.17 x 10-1 + 4.9 x 10-2) x (3.95 x 10-2 + 6.454 x 10-3) i know how to solve for the answer, i just dont know the correct number of sig figs...
Thursday, September 13, 2007 at 8:44pm by Jade

chem please
If 60 g water is evaporated from the solution at the same time as the temperature is reduced from 25.0 to 0.0 degree celsius, what mass of KNO3(s) will recrystallize?
Sunday, February 1, 2009 at 10:29pm by Erin

Chem
I need help setting this up, please. What is the specific heat of a substance if 1560 cal are required to raise the temperature of a 312g sample by 15C
Wednesday, May 27, 2009 at 11:44am by Kay

Chem.
How would you adjust the instrument for GC analysis to get better resolution? Please discuss. What is another GC detector and explain how it works and what sampler it is good for.
Monday, November 2, 2009 at 10:37pm by Chelsea

chem
Oh Dr.BOB...I am so lost..and sooo frustrated. Can you explain to me how to balance a chemical equation one more time please. Thanks Stacey
Tuesday, May 11, 2010 at 9:59pm by Stacey

Chem
Can someone please check this for me? It's ranking the following bonds in order of increasing ionic bond character. Cl-Cl C-H H-Cl Mg-C H-O Na-Cl Ca-O Cs-F I'm not sure where Fe-O, and Fe-C fall. Thanks -MC
Wednesday, February 19, 2014 at 8:07pm by mysterychicken

chem
Please calculate the energy involved in the following chemical reaction, given the values below: 2Ag + H2S --> Ag2S + H2 -24 -33
Sunday, March 2, 2014 at 8:59pm by lost girl

chem
Please calculate the energy involved in the following chemical reaction, given the values below: 2Ag + H2S --> Ag2S + H2 -24 -33
Sunday, March 2, 2014 at 9:14pm by lost girl

chem lab
hi im doing a post lab sheet for chem class. and im having a little trouble. i have: temperature 12.6 C -> 285.6 K Time 816 sec but im supposed to find 1/T(K) it looks like my classmate did this: 12.6 x 285.6 = 3598.56 however they gave me the response to group 2 also: and ...
Saturday, October 16, 2010 at 9:08am by chem

chem - br bob is this right
What is the pH of a solution prepared by adding 4.000 grams of NaOH to a 50.00 mL of a buffer that is 2.00 molar both in acetic acid and sodium acetate? (Assume final volume is still 50.00 mL) * chem - DrBob222, Wednesday, April 21, 2010 at 10:52pm * chem - phil, Wednesday, ...
Wednesday, April 21, 2010 at 11:05pm by phil

Chem
What causes dispersion forces? Disperson forces are caused by an unsymettrical distribution of charge in the molecule, causing a net electric force. http://www.chem.purdue.edu/gchelp/liquids/disperse.html
Tuesday, January 9, 2007 at 6:46am by Dennis

Gen Chem II
Thanks for the information Dr. Bob. Would you be able to work it out so that I can actually see the steps with the numbers and follow from there. The question was on Vitamin K from Sunday at 2:44pm which you answered at 3:45pm. Thanks again. I am looking to get a tutor since I...
Monday, February 11, 2013 at 5:28pm by Nefret

chem
6) How many significant figures should be retained in the result of the following calculation? 12.00000 x 0.9893 + 13.00335 x 0.0107 A) 2 B) 3 C) 4 D) 5 I thought it was 3, but it is 4. Can you please explain to me
Wednesday, March 11, 2009 at 3:28pm by Loi

chem
How many moles of base are needed to neutralize 2 mol of acid for HNO3 + KOH - KNO3 + H2O?. Can u show your work please:) Thanks a bunch
Tuesday, May 4, 2010 at 11:14pm by Stacey

chem can u check answer please
what is the hydrogen ion concentration of an aqueous solution with a pOH of 9.262? I got 5.47X 10 ^-10 is this correct? Thanks Andy
Sunday, May 23, 2010 at 10:36pm by Andy

chem
I am having a hard time with the following : 50 g HCl + 50g Ca(OH)2=H2O+? amt of CaCl2? I dont know how to set this prob. up.Please HELP!Thank you in advance....
Friday, November 12, 2010 at 9:01pm by joann

CHEM-PLEASE HELP
Calculate the molar solubility of silver chloride (AgCl) in: a-deionized water and b-.20M NaCl solution Given Ksp=1.6*10^-10
Thursday, April 25, 2013 at 12:21pm by JO

**Chem | PLEASE HELP!!!!!!!!
Divide 34700 by 0.00900 and enter the answer using the proper scientific "E" notation so that the result is within 1% of the exact calculation.
Friday, July 26, 2013 at 10:54pm by LILYYYYY

math/chem
If aluminum foil has a density of 2.70 g/ml, then how thick would be a 2.22 g sample of foilif it measures 5.0 cm on each side. PLEASE SHOW WORK THX!
Friday, September 27, 2013 at 10:40pm by john

Chemistry
What would happen if too much refrigerent was present in the system(refrigerator)? Too little? HELP!!! I'm doing a C^3 assignment for chem and its due tomorrow can someone help me please!
Thursday, November 7, 2013 at 10:24pm by K- High Anonymous

Chemistry
What would happen if too much refrigerent was present in the system(refrigerator)? Too little? HELP!!! I'm doing a C^3 assignment for chem and its due tomorrow can someone help me please!
Thursday, November 7, 2013 at 10:26pm by K- High Anonymous

Chemistry
What would happen if too much refrigerent was present in the system(refrigerator)? Too little? HELP!!! I'm doing a C^3 assignment for chem and its due tomorrow can someone help me please!
Thursday, November 7, 2013 at 10:50pm by K- High Anonymous

Chem--PLEASE HELP 911
A compound of carbon, hydrogen, and oxygen was burned in oxygen, and 2.00 g of the compound produced 2.868 g CO2 and 1.567 g H2O. In another experiment 0.1107g of the compound was dissolved in 25.0 g of water. This solution had a freezing point of -0.0894 degrees C. What is ...
Thursday, December 13, 2012 at 5:23pm by MSJO

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?
Friday, February 1, 2013 at 10:15pm by Devron

chem
how do you find the number of electrons in an ionic compound chart, if you haven't been given the charge? Would someone be able to please tell me? thanks
Monday, March 9, 2009 at 7:27pm by micah

chem
what is the Ka for a 0.1994M propionic acid solution if pH is 2.795? CH3CH2CO2H(aq)+H2O(l)<->CH3CH2CO2-(aq)+H3O(aq) someone please help.. I have a final in two days.
Monday, May 10, 2010 at 9:48pm by manda

Chem
given the balanced equation: 2Al2O3(s)-->4Al(s)+302(g) What is the total number of moles of O2 that are produced when 8.0 mol of Al2O3(s)are totally decomposed ? please help me.
Monday, January 3, 2011 at 12:54am by Martin

Chem
How many sigma bonds are there in trypophan? I know the answer is 28 but I don't know how to get that answer. Can someone please explain?? Thanks!
Friday, February 12, 2010 at 3:45pm by Lauren

Chem help please
A solution is found to contain 1 x 10-4 OH− ions, determine the pH of this solution.
Friday, November 16, 2012 at 12:55am by Trevor

please ..chem
When you touch an object, does the electrons from your hand exchange photons with the object?
Monday, February 24, 2014 at 8:56pm by Anonymous

please help me on chem
Commodity prices of NaCl and urea are about $0.033/lb for NaCl (as rock salt) and about $0.10/lb for urea. Calculate the cost of treating 1000 lb of ice on a surface to produce a solution thatmelts at -3.9 degrees Celsius with each chemical.I know you use to delta T= mkfi ...
Wednesday, February 27, 2013 at 12:53am by K

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