chem please help!

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can you please give me some practical applications of qualitative chem and quantitative chem...

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 25°C? chem - DrBob222, Tuesday, February 22, 2011 at 10:52pm q = mass water x delta Hvaporization. chem - Rebekah, Wednesday, February 23, ...


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!


What is another name for cardamist? Please write the formula and a link to its structure. See

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 R² = 0.6291 why is it wrong. im desperate please help! screen shot of my graph: ...


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

organic chemistry

whats the difference between inorganic chem and organic chem? im really confuse because mrs. white told us inoraganic is about ionic bonds while organic is about covalent bond. what is the difference between the twooo? please help me

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...


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 ...

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!!!


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


what are the other practical applications of Analytcal chem on being a medical technologist?

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


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!!:)


Dr Bob please answer below


Do you expect acetaminophen to be soluble in water? why or why not? please help... thanks


Do you expect acetaminophen to be soluble in 1.0 M NaOH? why or why not? please help... thanks

chem. AP

Please help? How would you convert 300 torr to mm hg?


how many atoms of C are in 2 moles of sucrose C12H22O11? please help


cr(s)--->Cr^3(aq)+3e- and Pb2+(aq)+2e---->Pb(s) write a balanced equation Please help thanks

org chem

Why does Oxygen8 has 2 lone pairs? Please help


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??


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...


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 don't know how im supposed to calculate it from this data please help!!!

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 don't know how im supposed to calculate it from this data please help!


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...

Chem Urgent!

I need help in balancing equation for NO2 + O2 -> NO + O3 Please help...

college chem

PLEASE..Determine [OH-]of a solution that is 0.270 M in HCO3-...thanks


convert 8.00in^3 to ml please tell me how to solve this what are the steps ,


calculate the PH of [OH-] = 4.5×10−3 M Please show how you work this problem.

chem please help

Find the number of moles of H2 in 1660mL H2 gas.

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.


balance the redox reaction NO2^- + Ag^+ = NO3^- + Ag

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...

chem help please!

what is the formal charge for OMe and how many electrons would it donate?


Is DrBob222 available tonight? Please let me know, I need some chem help.

Chem ap

What happens to cell potential as temperature decreases? Please explain

chem please..

are we exchanging force-carrying particles when we touch something?

Chem Help Please!

Explain why bromination of cyclohexene produces trans 1,2-dibromocyclohexane.

Chem Help Please!

Explain why bromination of cyclohexene produces trans 1,2-dibromocyclohexane.

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

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 ...

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!


Can someone show me the structural formula (lewis diagram) for ethene??? Please

Chem please help

Formulas for the covalent compounds: Diphosphorous monoxide Tetrasulfur hexaiodide


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

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

Chem Help Please!

Give the full mechanism for the reaction of 3-bromo-3-methylpentane with methanol. Thank you!


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) ...


A student mixed 6 g of ice at -3.4 degrees celsius with 1 g of steam at 103 degrees celsius. What was the final temperature of this mixture.i tried equalling mcdelta T. Please help asap. I would be eternally grateful. Please answer in kj or J only

CHEM 2: Boiling Point

Which Aqueous solution has the highest normal boiling point? a.) 0.1 m NaCl b.) 0.1 m C2H5OH c.) 0.1 m CaCl2 d.) They all have the same boiling point. I think that the answer is D, the all have the same boiling point. Is this correct? Because Delta T= K(b)msolute .... and if ...

Simple Chem O2

What is O2 mean? Also what is oxygen gas the formula? Please could someone answer this?

chem (urgent)

Can someone please explain to me in simple terms what the eutectic point and temperature are?

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


Please help how to set up How many grams of CuSO4 * 5H2O are needed to prepare of a 0.10 M solution?

Chem Help Please!

Explain why the stability of alkyl carbocations is: tertiary > secondary > primary > methyl Thanks!


Please give the complete mechanism for the acid catalyzed addition of methanol to 3 - methylbutene

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


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 ...

chem chem

hi does anyone know what the VSPER theory is

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


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

Organic Chem

how would you make 300mL of toluene and hexane in a artion of 70:30 respectively? i don't un derstand please help

Chem 2

Calculate the solubility of silver chromate, Ag2CrO4- in 0.005M Na22Cr)4- Ksp=2.6X10-12 HELP PLEASE......


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

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

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!!!

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 don't understand


rank the fallowing elements by increasing atomic radius: carbon, aluminum, oxygen, potassium. please help!

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

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

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

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


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


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

chem please help !!!!

what might one do to verify that the global strain energy minimum has been identified for a compound?

College Chem 2

calculate the solunility of silver chromate, Ag2CrO4, in 0.005 M NA2CrO4- Ksp=2.6x10-12 Please help.....

org chem

2 ethylpentane My answer for this is a correct name and structure but my teacher said it is incorrect.. Why? Please explain.


What is the balanced net ionic equation for aluminum foil reacting with hydrochloric acid ? (with steps please)


What concentration of Cl– results when 993 mL of 0.521 M LiCl is mixed with 883 mL of 0.309 M MgCl2? PLEASE HELP! I don't know how to set this up

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


Can someone please explain how I would write the equation for the hydrolysis of lactose using structural formulae? Thanks.


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.

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.

To DrBob222(Please check Chem)

(This homework question has been removed due to a copyright claim submitted by K12 Inc.)


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!


Please explain: 1) if MnO2 when in a fast reaction with H2O2 appear in balanced equation and 2)purpose of manganese dioxide. Thanks

org chem

Law of partition means? I think it is distribution? How is this applied in extraction involvong immiscible solvent? Help please.


calcualte the enthalpy change for the process in which 6.00g of steam at 100C is coverted to liquid water at a temperature of 35.0

AP Chem

What is the wedge dash notation for the SP hybridization of Carbon? Could someone please describe it, or do you have a link for it? I'm so stuck and lost! Thank you


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 30°C. Calculate the molar concentration of radon in the water. Can somepne please provide a step by step instruction?

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 ...


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 don't know the correct number of sig figs...

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, ...

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?


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.


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


I am having a hard time with the following : 50 g HCl + 50g Ca(OH)2=H2O+? amt of CaCl2? I don't know how to set this prob. up.Please HELP!Thank you in advance....


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


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


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