Chem Definition and 398 Threads

This is for a friend: The worksheet says: Name the following comounds: It has a picture, which is a benzene ring with 2 PhD groups off the 1 and 2 positions. Is also says "THis one is a pun. See if you can figure it out!" Thanks, nkk

If an element Z forms a compound with the formula AgZ, which of the following is a correct chemical formula? -CaZ2 -Al2Z3 -H2Z -NaZ3 I don't really understand this at all and there is going to be decent amount of them on my final exam! please any help

I was sick so I actually missed this lesson in class and this wasn't mentioned in the notes I got from a fellow student, nor is it in my textbook. I can't even find a definition for what it means that the heat of condensation is "evolved," so if anyone can fill me in on that I'd greatly...

I am currently a junior in the chemical engineering program at my school and have now started debating possible paths I can take after I graduate. What I'm interested in are what type of possibilities are out there for engineers who choose to Master in Physics and not in their respective...

Homework Statement A question on a pretest asks me to name this. I know it's either (1R,2R) or (1S,2S)1,2-Cyclopentanediol because the OH's are facing in opposite directions, but I'm not sure how to figure out if the OH's are S or R 2. The attempt at a solution I somewhat have an...

Hi guys, I've got a question which i couldn't solve. Both napthalene (two benzene ring join together) and benzoic acid are aromatic compounds which exist as white solids. Based on their physical ahd chemical properties, describe how you could separate the components of a mixture of these...

First of all, how do you know if a combustion process produce h2o(g) or h2o(l)? It depends on the temperature, but how do you figure that out? I found the heat released during the combustion processes, which should equate the work done by the system (theoretically). But according to w =...

Hi all, i have access to the two software: (Isis draw and Chem draw ultra.). I want to know how to draw a pentagon (cyclopentane) with a semicircle in it (to represent the alternative bond)..this kind of representations are widely use in many journals.. Can anyone help to how to draw it in a...

ok i am doing my lab report ow, and i am compeltely lost with some of these questions. it was a titration neutralization lab can get some help? 1- why is it necessary to dissolve the khp in water? 2- why is necessary to swirl the flask during the titration? i think the second one is so...

Chloroform is used to extract caffeine from water.If the distribution coefficient, KD=10.What relative volume of chloroform-water should be used to extract 90% of the caffeine present in one single extraction? Now i know that KD=Co/Cw and I've solved a question on how much weight of an acid...

I'm currently a high school senior. I self-studied for AP Chemistry (using Zumdahl) in 10th grade and would like to continue studying chemistry this year. My question is: what textbook should I use? In AP Physics last year, teacher simply gave us a whole bunch of formulas to memorize. I went...

Homework Statement A bicycle tire is filled with air to a pressure of 68 psi, at a temperature of 28°C. Riding the bike on asphalt on a hot day increases the temperature of the tire to 58°C. The volume of the tire increases by 3.9%. What is the new pressure in the bicycle tire? Homework...

Homework Statement Predict if the following salts are acidic, basic, neutral or undetermined. Homework Equations a. NaOCl b. NH4I c. Sr(ClO3)2 d. KCN The Attempt at a Solution A. NaClO = Na+ and ClO- So, if Na+ gives up a proton, that would turn it into Na... and...

http://www.google.com/hostednews/ap/article/ALeqM5gbl9HOrXrN5zLTpmFDu7ZnL88vTgD9B80NL80 And it seems nobody has a clue about the motive.

Homework Statement This is a chem problem for adding sig figs with base ten. The problem is: 3.15x10^-4 + 6.99x10^1 + 5 all divided by 7.73x10^-4. I was trying to help my daughter with this. Homework Equations The Attempt at a Solution I can do sig figs pretty well and these kinds of...

Homework Statement I've been balancing equations but this one has me really confused please help. C3H5(NO3)3----> CO2 +N2 + H2O + O2 Homework Equations The Attempt at a Solution So I know that it is a single replacement reaction, (well I think so) but I don't know how to make the...

Homework Statement http://carlodm.com/images/chem.png The Attempt at a Solution The attempt is in the image. HOW IS THIS WRONG?? I've looked at it for hours now!

Calculate the change in energy when the following transition occurs in the hydrogen atom. n = 4 ----> n = 1 equation E = -Rh/n^2 eventually my answer is 2.04E-18J because my book tells me to take 1 over n(low) squared minus 1over n(high) squared and multiply by rydberg constant.. so...

Homework Statement On a dry day, your body can accumulate static charge from walking across a carpet or from brushing your hair. If your body develops a charge of -18 (microcoulombs), how many excess electrons has it acquired? The Attempt at a Solution i don't know what to do...

Which grads are in greater demand right now?

Im try to make sure i understand something right. I have two jars on the left is oxidation takes place and on right reduction takes place. A wire connects them to allow electrons to move. electrons move from left side to right side. This makes the left side negative cause it produces electrons...

Homework Statement "Calculate the grams of acetic acid per liter of vinegar" Homework Equations Previous problem stated the multiply the average molarity of diluted vinegar times 10= 2.7 M Vinegar (acetic acid)= H(C2H3O2) molecular weight= 60.06 g The Attempt at a Solution...

I need to review 6 journal articles (approx. 150 words/article) relating to chemistry of the car (any topic). I need a topic which is going to allow me to easily identify the biases of the people who wrote the article, and that will be somewhat controversial, interesting and relevant to our...

Homework Statement When 100 mL of an aqueous solution containing 1.0 g of caffeine is extracted with 10 mL of chloroform at room temperature, 0.5 g of caffeine is transferred to the chloroform layer. Calculate the distribution coefficient of caffeine between chloroform and water at room...

The value of H° for the reaction below is -1107 kJ: 2Ba(s) + O2(g) --> 2BaO(s) How many kJ of heat are released when 5.75 g of Ba(s) reacts completely with oxygen fo form BaO(s)? i worked out the moles of Ba which was 0.0412 then times by -1107 whcih is 46.4 however the answer is...

hey guys I've got another problem, any conceptual help and help would the questions would be greatfully apprectiated. thanks Homework Statement From a consideration of the data below determine which of the given species will oxidize Fe to Fe2+: Data Fe2+ + 2e- --> Fe; E° = -0.44 V...

Homework Statement Refer to the cell below: Pt / MnO4-(0.10 M), Mn2+(0.20 M).H+(0.010M) // Cr3+(0.40 M), Cr2O72-(0.30 M), H+(0.010M) / Pt The standard reduction potentials are as follows: MnO4- + 8H+ + 5e- --> Mn2+ + 4H2O; E° = 1.51 V Cr2O72- + 14 H+ + 6e- --> 2 Cr3+ + 7H2O; E° = 1.33 V...

Homework Statement NaCl is added slowly to a solution that is 0.010M in each Cu+, Ag+ and Au+. Ksp's are 1.9x10^-7, 1.8x10^-10 and 2.0x10^-13 respectively. Which compound will precipitate first? Can anyone tell me how the Ksp is different from Ka? and the relationship to precipitation?

Homework Statement Calculate the mass of nitrogen dissolved at room temperature in an 80.0L home aquarium. Assume a total pressure of 1.0 atm and a mole fraction for nitrogen of .78. Homework Equations Mole fraction= moles solute/moles solution Sgas=KH x Pgas KH = 6.1 x 10-4...

Homework Statement 2NS(g) + 2H2(g)<---> N2(g) + 2H2S(g) @ equilibrium in a 4.L flask @ 25o C. 2.5 mol of eah component initially is put into the flask. At equilibrium, 2.5 mol of NS is present. what is Kc for the rxn at this temp?? Homework Equations Kc=[products]/[reactants] M=moles/L...

Homework Statement Discuss in detail (with the use of chemistry examples) whether the mole concept is fundamental and essential to chemistry, or merely a convenience concept. The bottom line question is "Could we do chemistry without the mole concept?" Homework Equations The...

Homework Statement I need to find net ionic equations for: -Fe(NO3)3 + NH3 -Cr(NO3)3 + NH3 -Cu(NO3)2 + NH3 -AgNO3 + NH3 -Cr(OH)3 + NaOH -Fe(OH)3 +NaOH and a whole bunch of other reactions. I have no problem with writing the balanced equations but I get a little stuck on breaking things...

How can you know if a complex ion has an optical isomer or not? I understand that it's when the mirror image can't be superimposed but am having trouble recognizing it. For example, take [Co(NH3)4F2]+. Does this have an optical isomer or just cis/trans?

Hello, I am a physics undergrad...getting ready for my final semester this summer. I have to take a chemistry class (actually, anything above a first General Chemistry class). It just so happens that the ONLY such Chem class they offer (small school) during my final semester is Organic...

1. Homework Statement The relative abundance of uranium isotopes in today’s Earth crustal material is: 99.2745% 238U 0.7196% 235U 0.0055% 234U What were the relative abundances when the Earth was formed 4.6x109 years ago? 2. Homework Equations t = age = 1/lambda * ln(N/No) N...

Homework Statement What percentage of the original Ag+ remains in solution when 175 mL of 0.0208 M AgNO3 is added to 250 mL 0.0380 M K2CrO4? Homework Equations The Attempt at a Solution I found the initial amont of CrO4 and Ag and put that into the equilbrium expression of...

Since Benedict's test is testing for the presence of a reducing agent (in the form of a carbohydrate), would that not mean it would give a false positive if acid was present (i.e. is acid not considered to be a reducing agent, it being a proton donor)?

Hi, I am supposed to design 2 experiments for my senior year Chem class. Right now I cannot think of anything that is interesting, relatively advanced but at the same time at a high school level (its only a design lab so I can include advanced equipments). Topics that interest me the...

Which of the following is a redox reaction? A. TiCl4(g) + 2 Mg(l) D Ti(s) + 2 MgCl2(l) B. NH3(g) + CO2(g) + H2O(l) NH4HCO3(aq) C. NaCl(s) + NaHSO4(s) D HCl(g) + Na2SO4(s) D. NaOH(aq) + H3PO4(aq) NaH2PO4(aq) + H2O(l) E. None of the above Is it A? Also another q. The primary reason for...

If you don't have a B. Eng. (and are not a certified engineer): Does it make sense to do an M. Eng.? What is the difference between the kind of jobs you can get with an M. Sc. in chemistry, and an M. A. Sc. or M. Eng. in chemical engineering? What about an M. Sc. plus MBA? I am one...

Right now, I'm torn between 4 majors, 2 of which are fairly similar (chem and chem engineering). My main questions is out of those 4, which one do you think will offer the best career options with just a B.S. Right now I'm not planning on a masters or PhD program. A few things about me...

Homework Statement A gas has a Henry's law constant of 0.150 M/atm. How much water would be needed to completely dissolve 1.49 L of the gas at a pressure of 720 torr and temp of 14 C.Homework Equations m = amount solute (in mol)/mass solvent(in kg) M = amount solute (in mol)/volume solution...

Homework Statement For the equilibrium PCl5 <---> PCl3 + Cl2, all gases, Keq = 4.16e-2. The equilibrium concentration of PCl5 is 1.0 M, and both PCl3 and Cl2 are 0.204 M. If the volume of this closed system is doubled, what are the concentrations of each gas when a new equilibrium is reached...

Homework Statement Write a detailed mechanism for the following reaction: Attached picture Homework Equations N/A The Attempt at a Solution Okay, I know this is PART of the mechanism for the oxidation of a glycol by periodic acid which causes cleavage of the C-C bond between the...

Hi I have two questions grade 11 chem questions that I don't know how to do. HELP PLEASE! Q1: Tetraethyl( Pb(C2H5)4 ) lead was added to gasoline up to 2.0ml per 3.8L of gasoline. a)Calculate the mass of Tetraethyl lead in the total amount of gasoline that you use for this trip (31.2 L of...

Homework Statement 800ml sample of 2.00 molar formic acid HCOOH (or HA) ismixed with 200ml of a 4.80 molar NaOH. Calculate the [H3O+] of the resulting solution. Homework Equations (for buffers) pH=pKa-log(HA/A-) Ka for formic acid is 1.8x10-4 pH=14-pOH [H+]=(1.00x10-14)/([OH-) The...

Hey guys, does anyone have a strong link for a Virtual Chem Lab for General Chemistry labs? It can be online or downloadable. Thanks

All relevant data is attached in a .jpeg. Ultimately, I have 4 equations with 6 unknowns. I found the correct answer through a chem calculator, but I'm wondering how it computed the balanced equation. Any insight much appreciated! Jeff

Homework Statement Which of the following solid substances can be liquefied simply by increasing the pressure suffciently? ice (H2O) diamond (C) dry ice (CO2) sulfur (S) graphite (C) Which of the following substances cannot be liquified at 1 atm pressure? nitrogen (N2) helium (He)...

Homework Statement Find the mg of Fe in vitamin pill. Vitamin pill was dissolved in 25mL HCl which was then diluted to 250mL with water in flask. 25mL of that solution was then diluted to 100mL in another flask. 10mL of the second was diluted to 100mL in another flask. Absorbance of the last...