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December 21, 2014

Search: Chem Help please!!!!!

Number of results: 54,275

chemistry
can you please give me some practical applications of qualitative chem and quantitative chem...
November 26, 2014 by Kara

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, ...
February 23, 2011 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!
April 5, 2013 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
September 4, 2005 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: ...
October 23, 2010 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
April 18, 2013 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...
April 17, 2011 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 ...
October 20, 2006 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!!!
March 16, 2014 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
May 14, 2009 by melissa

chem
what are the other practical applications of Analytcal chem on being a medical technologist?
November 26, 2014 by Arielle

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
May 23, 2010 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!!:)
March 18, 2013 by katlyn

chem
Dr Bob please answer below
January 5, 2009 by lyne

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??
January 22, 2013 by sara

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

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

chem. AP
Please help? How would you convert 300 torr to mm hg?
February 15, 2010 by Cindy

chem
how many atoms of C are in 2 moles of sucrose C12H22O11? please help
March 17, 2010 by suzie

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

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...
October 5, 2010 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...
October 10, 2010 by Kim

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

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

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

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

chem please help
Find the number of moles of H2 in 1660mL H2 gas.
July 17, 2013 by Anonymous

chem please help drbob222
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.
November 25, 2014 by Morgan

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!!!
February 18, 2010 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!
February 18, 2010 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...
October 27, 2009 by poppy

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

Chemistry
Is DrBob222 available tonight? Please let me know, I need some chem help.
October 11, 2010 by Karen

Chem ap
What happens to cell potential as temperature decreases? Please explain
April 3, 2011 by boots

chem please..
are we exchanging force-carrying particles when we touch something?
February 24, 2014 by Anonymous

Chem Help Please!
Explain why bromination of cyclohexene produces trans 1,2-dibromocyclohexane.
October 21, 2014 by JuYoung

Chem Help Please!
Explain why bromination of cyclohexene produces trans 1,2-dibromocyclohexane.
October 22, 2014 by JuYoung

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
October 23, 2011 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 ...
May 4, 2012 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!
December 7, 2010 by lavonne

chem
Can someone show me the structural formula (lewis diagram) for ethene??? Please
March 31, 2010 by Stacey

Chem please help
Formulas for the covalent compounds: Diphosphorous monoxide Tetrasulfur hexaiodide
February 23, 2012 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
March 11, 2012 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
April 1, 2014 by Anonymous

Chem Help Please!
Give the full mechanism for the reaction of 3-bromo-3-methylpentane with methanol. Thank you!
October 14, 2014 by Jesicca

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) ...
March 28, 2007 by Marisol

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

chem (urgent)
Can someone please explain to me in simple terms what the eutectic point and temperature are?
September 16, 2011 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
March 15, 2012 by Mackenzie

Chem
Please help how to set up How many grams of CuSO4 * 5H2O are needed to prepare 100.ml of a 0.10 M solution?
April 29, 2014 by Nicholas

Chem Help Please!
Explain why the stability of alkyl carbocations is: tertiary > secondary > primary > methyl Thanks!
October 21, 2014 by Kimberly

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
November 11, 2010 by JP

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
March 15, 2008 by Anynamous

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

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

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 ...
November 10, 2010 by hannah

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
February 19, 2008 by Lauren

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
October 19, 2012 by tracy

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!!!
October 30, 2010 by Sue

CHEM
rank the fallowing elements by increasing atomic radius: carbon, aluminum, oxygen, potassium. please help!
January 24, 2010 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
September 16, 2010 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
September 16, 2010 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
September 16, 2010 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
September 16, 2010 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
September 28, 2010 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
October 9, 2010 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
November 10, 2010 by sara

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

College Chem 2
calculate the solunility of silver chromate, Ag2CrO4, in 0.005 M NA2CrO4- Ksp=2.6x10-12 Please help.....
March 3, 2012 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
April 10, 2008 by Lisa

Biology/Chem
Can someone please explain how I would write the equation for the hydrolysis of lactose using structural formulae? Thanks.
March 20, 2007 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
December 6, 2007 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.
February 13, 2011 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.
March 18, 2012 by Kate

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

Chemisty
How many grams of Cl are in 38.0g of CF2Cl2? I really want to figure out how to do it. I can't seem to understand any of this Chem homework and it's getting me frustrated, please help!
September 26, 2014 by Luis

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?
December 12, 2011 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 ...
September 21, 2010 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...
September 13, 2007 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?
February 1, 2009 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
May 27, 2009 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.
November 2, 2009 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
May 11, 2010 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
February 19, 2014 by mysterychicken

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

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

chem please help drbob222
Why is it important in gravimetric analysis to add an excess amount of precipitating ions to a solution containing an analyte
December 2, 2014 by Morgan

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 ...
October 16, 2010 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, ...
April 21, 2010 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
January 9, 2007 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...
February 11, 2013 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
March 11, 2009 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
May 4, 2010 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
May 23, 2010 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....
November 12, 2010 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
April 25, 2013 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.
July 26, 2013 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!
September 27, 2013 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!
November 7, 2013 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!
November 7, 2013 by K- High Anonymous

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