What is Chem: Definition and 424 Discussions

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...

I have this proplem as a homework assignment and I'm a bit stuck as houw to set it up. Here it is: Propane gas enters a continuous adiabatic heat exchanger at 40 degrees C and 250 kPa and exits at 240 degrees C. Superheated steam at 300 degrees C and 5.0 bar enters the exchanger flowing...

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

Just came back to school.. and I realize I've forgotten so many things! :cry: ARGG! >_< So if anyone can, I would really appreciate it you could help and show me how to do these problems asap!1) An element consists of 1.40% of an isotope with mass 203.973 amu, 24.10% of an isotope with mass...

4PH3(g) ------- P4(g) + 6H2(g) If, in a certain experiment, over a specific time period, 0.0063 mol PH3 is consumed in a 2.0 L container each second of reaction, what are the rates of production of P4 and H2 in this experiment. Any idea about this problem? divide 2.0 to 1.0 and then .0063 to...

Which course is best to do at summer school, Chemistry or Wold History w/Geography? Both classes are required, so I need to take one to make room for other classes in the Fall.

how good an insulator is asbestos? (thermal conductivity 0.15 W/ m K). I am trying to determine the thickness of insulation required to reduce the heat loss of a spherical container by half. The answer I calculated it to be is 0.2cm which to me doesn't seem right (too small?) but having no...

Reaction: CH_4 + 2H_2S <-> CS_2 + 4H_2 k_{eq} = 100 at a certain temperature An unkown amount of reactants were intorduced into a 1.0L bulb and at equilibrium 0.10 mol of CH_4 and 0.30 of H_2S were found. Calc \[CS_2\] at equilibrium. I don't seem to have enough information here. I can form...

In my chmeistry lab i use a pipet 5.0 ml of HCl and add it to a beaker. To this beaker I also added 5.0 ml NaOH. I stir the mixture and when a red litmus it turn to blue and when i put a blue litmus it stay blue. So that means its a base, but since its a mixture of an acid and a base shouldn't...

Hey can anyone help me with this question? What is the major product from the acid-catalyzed hydration of 3-methyl-2-pentene? a. 3-methylpentane b. 3-methyl-1-pentanol c. 3-methyl-2-pentanol d. 3-methyl-3-pentanol e. 3-methoxypentane Would the answer by D? My reasoning is that when...

1. if you want to draw the electron dot structure for say carbon (4 valence electrons) would you draw it with one dot on each side or two on one side, and one on two other sides? 2. can someone give me a link that helps discuss hybridization - i don't really get it and i need help...

it seems like most of the posts in this forum get moved to hw. come on now, can't we have any good chem topics that don't have to do with hw?

Does anyone have any links or places for me to look for a crash course in enthalpy, bombo calorimeter, and equations dealing with molecular weight or moles in general? I took a physics class worried about my lack of chemistry background, but everyone told me not to worry about it... Well...

I searched the internet for the answers and i keep coming up short maybe someone could help? 1. Which of the following is an empirical formula? a) C5H10O5 b) C6H12O2 c) C12H17OH Which of the following is an empirical formula? NaO C2H8N2 C6H3Cl2 What is the percent...

Could someone could help me with this reaction rate problem? 4PH3(g) ------- P4(g) + 6H2(g) If, in a certain experiment, over a specific time period, 0.0048 mol PH3 is consumed in a 2.0 L container each second of reaction, what are the rates of production of P4 and H2 in this experiment. I'm...

I need to include net ionic eq, phase symbols, etc. 1. Sulfur trioxide is heated with carbon dioxide. 2. A solution of strontium chloride is mixed with a solution of sodium sulfate. 3. Hydrochloric acid is added to sodium hydroxide My work: 1. SO3(g)+H2O(l)---->H2SO4(aq) 2...

[CHEM] Equlibrium Help please! Hi, I am having trouble with a few questions on my chapter review and I have a test tomorrow. I wasn't at school today so I didn't get the chance to ask questions. 1. The oxidation of sulfur dioxide to sulfur trioxide is an important reaction. At 1000K, the...

Hey everyone =) I am nearing my completion of the chemistry unit, and I have to do a huge lab report before I write my unit test..:frown: For the lab basically, we are comparing acid-neutralizing capabilities of baking soda and antacid substances. We are going to.. - mix measured amounts of...

What does the ic suffix mean in compound names? For instance ferric, plumbic, cupric? I'm guessing it has something to do with the charge on the metal ion? I have some nomenclature rules from my teacher but this isn't covered. Thanks.

HELLO EVERYONE can anyone help me wit this what is the role of chem. engg in new emerging fields i.e. BIOTECH.NANOTECHNOLOGY & ENVIRONMENTAL ENGG. DO REPLY

What possible experiments (not college level).. can you think off where the bio aspect of sight can be "tested" on.. anything from colorblindness.. to the blind spot... someone suggested getting a cow eye .. not sure if I will be able to get a hold of one here in San Diego though. (I also...

Ok so this problem pissed me off to no end... basically because ih ad 5 minutes to do it and couldn't figure it out. Now, i divided the 120g by the molar mass of PF3 and divided by .846 to find the actual amount necessary which gave me 1.612449659 moles. Multply that by the molar mass of F2...

2 a) Calculate the expected mass of one mole of 31^P atoms that the avogadro constant equals 6.0225 x10^23, the mass of one electron equals 9.1091x10^-28g, the mass of one proton equals 1.6725x10^-24g and the mass of one nuetron equals 1.6748x10^-24g. b) The actual mass of one mole of 31^P...

Could anybody tell me, in whatever units, how much energy per volume (and by mass if you know) is released by the most powerful chemical reactions?

Only three weeks into organic chemistry I, and I'm already feeling hopelessly confused. Can anyone recommend a good study guide or book to help clarify the basics, and explain the big picture? Thanks!

chem word problem ! please help Hi , This is a Hw question i have am stuck on i don't know how to solve it ... A pharmacist is to prepare 16 milliliters of special eye drops for a glaucoma patient. The eye-drop solution must have a 5% active ingredient, but the pharmacist only has 10%...

In the following calculation ( ( (5.70 x 10.02) − 7.2356) ÷ 0.014 ) + 1 the number 1 is defined as exact. Give the correct answer to this calculation with the correct number of significant figures. I am having a whole lot trouble with finding the correct significant...

I am currently thinking about choosing Chem Eng. as a major. I am very interested in what those who have this degree think about it. why is it a good/bad choice? what were some hard classes/subjects? where you plan on taking this degree? what are salaries like? I am interested in everything...