Chem Definition and 398 Threads

I have a problem where I am given an equation of state pV=RT+(bRT-a)/V and asked to find the work produced in the isothermal, reversible expansion from V1 to V2. I thought I would want to use W=-integral(nRT/V)dV, but that is apparently only for ideal gases, and this problem concerns a...

Homework Statement 5.00g alloy of Magnesium and Aluminum is treated with excess HCl, forming MgCl2 and AlCl3 and 6.65L of H2 at 25 degrees celcius and 99.2kPa. What is the mass percent of Mg in the alloy? Homework Equations PV = nRT The Attempt at a Solution Using PV = nRT...

Homework Statement Hydrogen peroxide decomposes into water and oxygen gas with the help of a catalyst. write the molecular formula and the redox half reactions. Homework Equations (N/A) The Attempt at a Solution the molec. formula is of course 2 H_{2}O_{2} (l)...

Homework Statement Balance this redox equation. Homework Equations Ag + H^{+} + NO_{3} ^{-} \rightarrow Ag^{+} + H_{2}O + NO The Attempt at a Solution Using a conventional balancing mechanism I got these coefficients: 1 + 8 + 2 -> 1 + 4 + 2 but the correct...

[SOLVED] help setting up a CHEM E problem Homework Statement Three fillers used in packaging a pharmaceutical emulsion (ro = 1050kg/m^3) are fed from a single product line. One filler has a capacity of 2700kg/h, the second operates at 4600 kg/h and the third at 6800 kg/h. The emulsion is...

Hi, I'm taking AP Chem this year, and we just had this big assignment. I got through most of it, but here's some I need a walkthrough with. Homework Statement A titration is done using .1302M NaOH to determine the molecular weight of an acid. The acid contains one acidic hydrogen per molecule...

here is the question: The entire contents of one of the Erlenmeyer flasks used in the oxalate-permanganate titration in Experiment 8 was poured into a 250 mL volumetric flask. The volume was made up to 250 mL. A 20 mL portion of the solution was placed in a 100 mL volumetric flask and 20 mL...

Homework Statement In lab, a student decides to analyze a 0.6118 g sample containing only magnesium chloride and sodium chloride. He does this by adding 145 milliliters of 0.1006 M silver nitrate. A precipitate, silver chloride, is formed, which has a mass of 1.7272 grams. Using this data...

Is anyone here able to help me or point me in the right direction? Iron ores often involve a mixture of oxides and contain both Fe 2+ and Fe 3+ ions. Such an ore may be analyzed for its iron content by dissolving it in an acidic solution, reducing all of the iron to Fe 2+ ions and then...

Homework Statement A sample of 2.00 mol. CH3OH (g) is condensed isothermally and reversibly to liquid at 64*C. The standard enthalpy of condensation of methanol @ 64*C is -35.3 kJ/mol. Find w and q for the reaction. Homework Equations w = -nRT * ln(Vf/Vi) (although I don't have volume...

Organotin compounds play a significant role in diverse industrial applications. They have been used as plastic stabilizers and as pesticides or fungicides. One method used to prepare simple tetraalkylstannanes is the controlled direct reaction of liquid tin(IV) chloride with highly reactive...

Homework Statement A solution is made by disolving 0.40 mol isopropanol (C3H7OH) in 0.70 mol water. (a) What is the mole fraction of isopropanol? (b) What is the mass percent of isopropanol? % (c) What is the molality of isopropanol? m Homework Equations...

I have just started AP Chemistry this year as a junior at my high school despite all peer protests against it. And I admit so far the course has lived up to it's reputation of being very difficult. I was rather ecstatic to come across this site where I may obtain the help I /know/ I will need...

Hello, I need to make sure I understand some of the reactions correctly... For example: CH2OHCH3 in H+ will give us CH2=CH2. I would think that here the H+ bonded with the OH resulting in H2O (a leaving group), but I am not sure what happens to the other leaving H. In RC≡CR' in Na/NH3...

Hi, I was just wondering if anyone had any advice on sources of steam ejector design principles. I've seen one textbook on the topic of steam ejectors that is now out-of-print, and haven't been able to find any suitable online resources (generally, they're very basic and don't quantify much...

I'm a chemical engineering undergraduate studying in Canada right now. I'm not too sure what my future looks like, so I'd like to have some opinions on whether it's a good engineering discipline to stick with. 1. I'm interested in a career in R&D, but I hear that you need at least a PhD. I'm...

we ofen hear the terms organic, natural and chemical in the media. Organic and natural are usually used to imply that a product is "healthy" and/or "environmentally friendly" while chemical often implies negative implications for health and for the environment. In your opinion are these...

P. Chem--advice? I know, a physics major taking P. chem...why would he put himself through that? However, the topic has peaked my interest and it appears that what I want to do research on will require a knowledge of P. Chem, so my question is simply: Anyone have any survival advice? The...

Hello, I needed some help with my Chemistry Homework. I have 4 questions that I'm not so sure of the answer. I've given my best try. Please if someone can help me correct my answers or tell me which one is the right one and how to determine/solve it... Thanks in advance. Question One...

Can some body please help me on my homework. The problem is in the link image below (click to go to it) http://img501.imageshack.us/img501/1126/helplr7.jpg" I'd know how to do that problem if it said "initial rate (M/s)" in the last column, but it says "Reaction time (seconds)" and I...

Homework Statement My questions pertain to #4b of the free response. Question: Excess nitric acid is added to solid calcium carbonate. The question asks to predict a balanced equation for this reaction. The Attempt at a Solution what I wrote down was: H+ + CO3 ----> H2O...

Homework Statement All I'm trying to do is translate the cell diagram below into a into a an equation so I can determine which is the anode and which is the cathode. Here is the cell diagram. I know how to balance it, I just want to make sure I'm putting reactants and products on their...

I'm very confused with an electrochemistry lab. For the lab, we used Al+3, Cu+2, Fe+3, Zn+2, and KNO3. The setup was wells with all of the solutions in them. We soaked a piece of paper(filter paper) in KNO3 for the reactions, then used the paper as a salt bridge between the solutions of the...

After drawing the 8 alcohols with the formula C5H11OH, I'm asked to "Describe how they are formed and give two uses for this type of alcohol." The only example in my text for this is the hydration of an alkene which, at a glance, wouldn't make sense for 2,2-dimethyl 1 propanol. Is this one...

This is the question: If 20 mL of a 0.3M solution of NaOH is required to neutralize 30.0 mL of a sulfuric acid solution, what is the molarity of the acid solution? I just need to get pointed in the right direction and then just some simple steps from there... Thanks H20h

Homework Statement The standard Gibb's free energy for the reaction N2+3H2<--->2NH3 is -33.0 KJ at 298 K. Everything is a gas. Calculate Kp for this reaction. Homework Equations I have in my notes that Keq=e^(-Delta G/RT) where R is the constant 0.008314 KJ/K. I also have a formula...

Homework Statement The question asks: Using the measured cell potential and the Nernst equation, calculate the [Ag+] in the test solution. However, you guys will need a little bit of background information to answer this question since it is a lab. First of all this reaction was: Ag2CO3(s)...

Homework Statement Kk so the problem is that we have 55.48 ml of NaOH was required to titrate 25 mL of a weak monoprotic acid. After 31.64 mL of NaOH had been added, the pH is 4.96 for the solution. Calculate the Ka and pKa for this weak acid. Homework Equations pKa= pH +...

Homework Statement How many pi bonds are in the molecule C12H18? Homework Equations I have in my notes the formula (6nPi+2-total # of electrons)/2. The Attempt at a Solution Unfortunately I can't find an explination for this formula in the book and I don't remember what was...

My daughter and a large portion of her class are struggling in AP Chem. Any has any link or have any beneficial suggestion for her. She is very motivated. She only has a grade of "C"

Homework Statement I am to draw a structural diagram of 2,4-dimethyl-1-heptyne. 2. The attempt at a solution ----------CH3 CH=C-CH2-CH-CH2-CH2-CH3 ---CH3 I tried just using spaces but it wouldn't indent them so I used hyphens. Now, I'm fairly certain my answer is correct (one of...

How difficult is a College Level General Chemistry I class? I took Honors Chem in 10th grade under a very good teacher (30+ years in Chemistry field) but don't have that fond of a memory of the field. My little brother is currently taking a Chemistry class so I have his notes/book to go over...

I'm currently attending a community college and I'll be transferring to one of the UC schools after this spring semester as a physics major. Of the 5 schools I'm applying to, only 1 of them requires General Chem II, and that school is one of my lower priorities. I'm currently enrolled in Gen...

please help guyz its a project...

i have a take home "test" that my teacher allows me to use other resources including my book. i really didnt understand kinetics. can you explain to me by answering these questions? 4)(c) Provide a molecular explanation for the dependence of the rate of the forward reaction on the...

I was just wondering what expierence has anyone had with the ACS Chem Exam, Good? Bad? Why?

I am having trouble answering the following question any help would be greatly apperciated. 1. A protein must be synthesized by a cell. Part of the amino acid sequence in this protein is: -Ala-Gly-Thr-Leu- The codons for these amino acids are: Gly -- G G C Leu -- C U A Thr -- U...

Here is a problem on my Chem. Final and I seem to have lost my notes for this parituclar problem. Can anyone give me an idea on where to get started? Thanks Here is the problem: http://www.fuzzyb3av3r.com/chem.doc"

omg Chem Titration help fast! Ok so I'm a gr11 student who just had a titration exeriment.. and there are a couple of things that are really screwing me over! Okay so we used an indicator, Phenolphthalein, more specifically, and when we stopped the titration when it turned light pink. My...

Hello, I just have a question regarding this problem. Please tell me if its correct. I have to identify the substance oxidized, the substance reduced, the oxidizing agent, and the reducing agent. http://xs109.xs.to/xs109/06462/chem..png For the first one This is what I believe: H2O2...

Do physics majors normally take chemistry? The reason I ask is that I'm currently taking Chem 1 w/ lab and Calculus 1. I chose to take chem because I can't take physics until I have some more calc under my belt and I thought it would be beneficial; however, I'm considering not taking chem 2...

Question: A sample of hydrogen gas, collected at 100 C and 1.0 atm., has a volume of 350 ml (0.350 lit.). What will be the pressure after it is transferred to a 4.0 lit. flask and cooled to 25 C? (temp must be in degrees of Kelvin) I had assumed using the formula V2 = P1 X V1 / P2 but i am...

Chem Lab "ID of Unknowns" I had to find 5 unknown solutions in a recent chem lab and now I am doing the equations, but I am not sure about two of them: Deep blue percipitate NH3 (aq) + CuSO4 (aq) -------> Cu(NH3)4 SO4 (s) brown heavy percipitate 4NaI (aq) + 2CuSO4 (aq) -------> 2CuI (s)...

For the purpose of drawing dot structures and determining VSEPR shape, how do I figure out the number of valence electrons for inner transitional metals? Do I only count the electrons in the highest p and s orbitals, or do I also count the electrons in d,f,etc. orbitals? Clarification on this...

So I have to use Le Chateliers principle to expalin why low pressure is used in the freeze-drying process (eg in making instant coffee) So here is what I know so far: in freeze drying, they turn solid water right into a gas basically removing all moisture from the food so it keeps for a very...

This is basically the lab I typed up tonight to hand in tomorrow. I'm wondering: 1. Does it look okay? 2. Is there any additional information I should add/anything to take out? 3. Is my third calculation totally off or is it just experimental error? Purpose: To calculate the molar enthalpy...

I am new to AP Chem and given a problem that I cannot begin to figure out how to compute. None of my calculations come up with the correct answer. How do I work through this? PROBLEM: A sample containing NACl, SA2S04 and NAN03 (the number are sub), gives the following elemental analysis...

I am in Chem AP in high school and it is rediculously tough. Although, I try to study the book by myself, but I always have questions. Too many to ask the teacher. I was wondering if you guys could clear those out. Thx a lot. 1. I read in the book that H20 is acid. But I always thought...

It has been a long while since I have had to calculate normality. If I remember correctly the formula for normality is: N=g/(equiv wt x Vol) or NAcidVAcid=NBaseVBase The known values given are the normality of the base and the volume of the base. Since the normality of the acid is the...

Which has a higher density, oxygen or air? Prove by calculations, knowing that air is approximately 20% oxygen and 80% nitrogen and that 1 mol of any gas occupies 22.4liters at STP