Monday
April 21, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Post a New Question | Current Questions

Chemistry - Science (Dr. Bob222)
Consider the kinetic data given in the table below for the first order reaction: What is the value of the activation energy? A_2_--> 2A Expt. Initial [A2] Temp. Initial Rate mol/L (°C) [A2]·s–1 1 0.10 100 1.2 x 10–3 2 0.20 200 4.8 x 10–3 3 0.15 ? 4...
Wednesday, April 16, 2014 at 7:02pm

Chemistry
I have made mistakes like that but in this case I didn't. It could be either way. Which ever way you do it will work out. If you assume you started with HI, then 2HI ==> H2 + I2 and the EQUILIBRIUM MIXTURE will be as given. Then you work out Kc for that reaction. You ...
Wednesday, April 16, 2014 at 6:46pm

Chemistry
When a sample of potassium nitrate is heated, oxygen gas is produced. This gas, collected in a 750 milliliter flask, has a pressure of 2.8 atmosphere and the temperature is recorded to be 53.6°C. How many moles of oxygen gas are produced in this reaction? (R = 0.08205 L ...
Wednesday, April 16, 2014 at 6:43pm

Chemistry
Actually all of these can be worked using the table of reduction potentials but I will give that process last and show shortcuts for metals vs metal ions and for halogens vs halogen ions. The metals are done by looking at the activity series of metals. Here is a simplified ...
Wednesday, April 16, 2014 at 6:35pm

Chemistry
Thank you, but I have one more question. In your solution, wouldn't the equilibrium constant equation be [HI]^2 / [H2][I2] Wouldn't HI be the product and H2 and I2 be the reactants?
Wednesday, April 16, 2014 at 6:08pm

Chemistry
First, convert mols to M. (HI) = 7/10 = 0.7M (I2) = 1/10 = 0.1M (H2) = 1/10 = 0.1M Next calculate the Kc. 2HI ==>H2 + I2 Kc = (H2)(I2)/(HI)^2 Kc = (0.1)(0.1)/(0.7)^2 = approx 0.02 Then do and ICE chart. ............2HI ==> H2 + I2 I...........0.7....0.1...0.1 add...
Wednesday, April 16, 2014 at 5:58pm

Chemistry
The reaction is favoring the products. In other words when you have a reaction whose number is 0 you are at a perfect equilibrium, when you have some number smaller than that you have a greater number of reactants than products. When you are above that you a greater number of ...
Wednesday, April 16, 2014 at 4:56pm

chemistry
I have no idea either please help
Wednesday, April 16, 2014 at 4:56pm

Chemistry
An equilibrium mixture in a 10.0 L flask contains 7.0 mol HI(g) and 1.0 mol each of I2(g) and H2(g). If 2.5 mol H2, 5.0 mol I2 and 2.0 mol HI are added to that equilibrium mixture how many moles of each gas will be present when equilibrium is reestablished?
Wednesday, April 16, 2014 at 4:49pm

Chemistry
Write the balanced net ionic equation for the following? a) Copper metal and zinc ion b) zinc and cupric ion c) Copper metal and hydrogen ion d) zinc metal and hydrogen ion e) iron metal and hydrogen ion f) Chlorine (Cl2) and bromide ion (Br-) g) Chlorine (Cl2) and iodide ion...
Wednesday, April 16, 2014 at 3:53pm

Chemistry
The equilibrium constant can be calculated by: Kc= [product]/[reactants]. Before you know the exact concentration variables necessary to do this you need to calculate the moles present in your reaction. In the example you provided the moles per liter are: H2S= 8.7M/12.0L= 0.73...
Wednesday, April 16, 2014 at 2:56pm

Chemistry
follow my blog
Wednesday, April 16, 2014 at 2:44pm

Chemistry
timmmy
Wednesday, April 16, 2014 at 2:44pm

Chemistry
786
Wednesday, April 16, 2014 at 2:44pm

Chemistry
678
Wednesday, April 16, 2014 at 2:43pm

Chemistry
Write the balanced net ionic equations for the reactions of the halogens with copper metal. The halogens are oxidizing agents and the copper metal is a reducing agent. a) Bromine (Br2)+copper metal (Cu) b) Iodine (I2) + copper metal (Cu) Based on your observations and ...
Wednesday, April 16, 2014 at 2:41pm

Chemistry
so would it be n=4 since that is the largest outer shell ms= + 1/2, -1/2 since it has 2 electrons in 4s but what would happen if it was 3d? Would that be times by 5? and I'm still a little confused on what the two others represent. I'm sorry for being such a bother!
Wednesday, April 16, 2014 at 2:17pm

Chemistry
For a 1 tesla field the Larmor frequency is freq = 28.025 GHz. http://hyperphysics.phy-astr.gsu.edu/hba​se/nuclear/nmr.html
Wednesday, April 16, 2014 at 2:15pm

Chemistry
Explain how you woud make 200.0 g of a .900 percent by mass solution of salt (NaCl in water)
Wednesday, April 16, 2014 at 2:10pm

Chemistry
I think so although no number is placed on it in that table you looked at. Most might say iodine since there is so little At around.
Wednesday, April 16, 2014 at 2:08pm

Chemistry
n is the principal quantum number and in general terms is the old Bohr shell. l (ell) is the azimuthal quantum number and describes the ellipticity (how elliptical) of the orbit. ml describes how the orbit is arranged in space ms describes the spin of the electron; i.e., ...
Wednesday, April 16, 2014 at 2:06pm

Chemistry
Astatine?
Wednesday, April 16, 2014 at 2:03pm

Chemistry
Why can't you simply substitute into the formula given in the problem?
Wednesday, April 16, 2014 at 2:01pm

Chemistry
What does each stand for? So if I am doing it for fluorine, what would n, l, ml, and ms represent? For instance, is n the sublevel or what? I'm rather confused.
Wednesday, April 16, 2014 at 2:00pm

Chemistry
http://en.wikipedia.org/wiki/Template:Pe​riodic_table_%28electron_affinities%29
Wednesday, April 16, 2014 at 1:59pm

Chemistry
You need to learn to do these. Here are the rules. n can be any whole positive number beginning with 1, 2, 3, etc. l(ell) can be any positive whole number beginning with zero but can't be larger than n-1 ml can have values from -ell to + ell. ms may have either of two ...
Wednesday, April 16, 2014 at 1:56pm

Chemistry
A column of mercury in a barometer is 767.3 mm Hg high. Note, that in order for the pressures to be equal, density and height of a column are inversely proportional, therefore, (den1)(h1)=(den2)(h2). The density of mercury is 13.6 g/mL and the density of water is 1.00g/mL. a) ...
Wednesday, April 16, 2014 at 1:54pm

Chemistry
List all the quantum numbers for each of the 9 electrons in fluorine n L m sub L m sub s 1. 2. 3. 4. 5. 6. 7. 8. 9.
Wednesday, April 16, 2014 at 1:33pm

Chemistry
Which halogen has the lowest electron affinity?
Wednesday, April 16, 2014 at 1:31pm

Chemistry
1355.37
Wednesday, April 16, 2014 at 12:41pm

Chemistry
Good morning, I am looking for help in figuring out how to solve this problem, knowing that the magnetic field was just calculated to be 9.39 tesla. Is there a specific formula and is there any information I'm missing to be able to solve this question? What is the resonant...
Wednesday, April 16, 2014 at 10:13am

Chemistry
209
Wednesday, April 16, 2014 at 10:01am

Chemistry
What do you mean you don't know where to start. This is just a case of substitute and solve. 7.7E24 = Kc(0.08205*298)^(4-2) Solve for Kc.
Wednesday, April 16, 2014 at 1:09am

Chemistry
Calculate Kc. CH_4(g) + H_2O(g) <-> CO(g) + 3H_2(g) Kp= 7.7 x 10^24 at 298K. Should I use the formula Kp= Kc(RT)^Deltang If so I have no idea where to start.
Wednesday, April 16, 2014 at 12:52am

Chemistry
A. The reaction for A is just the reverse of the original; therefore, the new Kp(that is K'p) for the new rxn will be 1/Kp B. B is just 1/2 the original; therefore, the new Kp (that's K"p) will be sqrt(Kp) For any reaction of A ==> B, then Kp = pB/pA. So when ...
Wednesday, April 16, 2014 at 12:30am

Chemistry Help
Coulombs = amperes x seconds = approx 3000. 107 g Ag will be deposited for every 96,485 coulombs. So Ag deposited is 107g Ag x (approx 3000/96,485) = ? g Ag.
Wednesday, April 16, 2014 at 12:23am

Chemistry Help
How many grams of silver will be obtained when an aqueous silver nitrate solution is electrolyzed for 22.0min with a constant current of 2.28A ?
Wednesday, April 16, 2014 at 12:19am

Chemistry
The reaction has an equilibrium constant of Kp=2.26x10^4 at 298 K. CO(g) + 2H_2(g) <-> CH_3OH(g) Calculate Kp for the reactions and predict whether reactants or products will be favored at equilibrium. A. CH_3OH(g) <-> CO(g) + 2H_2(g) B. 1/2CO(g) + H_2(g) <->...
Wednesday, April 16, 2014 at 12:15am

chemistry
mols sample = 0.05/114 = approx (but you do it for the real number) = 0.00044 q = mass H2O x specific heat H2O x delta T. q = 200g x 1 cal/g*C x 5.7 q = approx 1100 calories for 0.05g or 1100/0.05 = approx 23000 calories 23,000 calories x (1 kcal/1000 cal) = 23 kcal = 23 ...
Tuesday, April 15, 2014 at 11:56pm

Chemistry
I differ slightly (84.82) probably because you rounded to 1.62 while I kept everything in the calculator until the final answer. But to three significant figures I would round the answer to 83.8 (probably krypton).
Tuesday, April 15, 2014 at 11:48pm

chemistry
a 0.0500 mol sample of a nutrient substance is burned in a bomb calorimeter containing 2.00 x 10^2g H2O. If the formula weight of this nutrient substance is 114g/mol, what is the fuel value (in nutrient Cal) if the temperature of the water increased 5.70C
Tuesday, April 15, 2014 at 11:40pm

chemistry
3,5,5 look just like 1 and 2. 6 and 7 are done by working backward. delta T = i*Kf or Kb *m You're given delta T, solve for m. Then m = mols/kg solvent. Solve for mols Then mols = grams/molar mass. You're given mols and grams; solve for molar mass. i = 1 for both 6 and 7
Tuesday, April 15, 2014 at 11:39pm

chemistry
2. Find the freezing point of a solution composed of 50g IBr in 120 g of water. Assume 100% ionization. KBr = k1+Br1-. I assume you made a typo and IBr really is KBr. mols KBr = grams/molar mass. Solve for mols. molality = m = mols/kg solvent Solve for m delta T = i*Kf*m i for...
Tuesday, April 15, 2014 at 11:36pm

chemistry
1. Find the boiling point of a solution composed of 110g of HgCl2 (a non-ionizing solute) in 175g of water. mols HgCl2 = grams/molar mass Substitute and solve for mols. molality = m = mols/Kg solvent Substitute and solve for m delta T = i*Kb*m Your post says i = 1 Kb = 1.51 ...
Tuesday, April 15, 2014 at 11:32pm

Chemistry
I got to 1.62 = sqrt(M unknown/M O2) I know that the molar mass of O2 is 32 So I squared both sides of the equation to get 2.6244 = M unknown/ 32g O2 Multiplied 2.6244 x 32 = 83.98g/molunknown
Tuesday, April 15, 2014 at 11:30pm

Chemistry
(rate1/rate2) = sqrt(M2/M1) Substitute and solve for molar mass.
Tuesday, April 15, 2014 at 11:21pm

chemistry
I have the answers, I am just interested in the formulas so that I can solve the problems, thanks! 1. Find the boiling point of a solution composed of 110g of HgCl2 (a non-ionizing solute) in 175g of water. 2. Find the freezing point of a solution composed of 50g IBr in 120 g ...
Tuesday, April 15, 2014 at 11:20pm

chemistry
dGo = -nFEo Solve for n. That will give you the change in electrons.
Tuesday, April 15, 2014 at 11:19pm

Grade 12 Chemistry
When 50.0 mL of 1.0 mol/L hydrochloric acid is neutralized completely by 75.0 mL of 1.0 mol/L sodium hydroxide in a coffee-cup calorimeter, the temperature of the total solution changes from 20.2 to 25.6. Determine the quantity of energy transferred, q, and state whether the ...
Tuesday, April 15, 2014 at 11:00pm

chemistry
What is the value of x for the following reaction if E∘=1.43V and ΔG∘ = -276kJ ? A+B^x+→A^x++B
Tuesday, April 15, 2014 at 10:24pm

chemistry
chemistry 101
Tuesday, April 15, 2014 at 10:23pm

Chemistry
Under identical conditions, separate samples of O2 and an unknown gas were allowed to effuse through identical membranes simultaneously. After a certain amount of time, it was found that 4.92 mL of O2 had passed through the membrane, but only 3.04 mL of of the unknown gas had ...
Tuesday, April 15, 2014 at 10:21pm

chemistry
did you figure it out
Tuesday, April 15, 2014 at 9:39pm

chemistry
You can calculate delta S for the system and delta H for the system at 25 degrees C by using dHo formation and dSo formation and dHo rxn = (n*dH products) - (n*dH reactants) dSo rxn = (n*dH products) - (n*dH reactants). What's the temperature. dS surrounds = -dH/T dS ...
Tuesday, April 15, 2014 at 9:07pm

CHEMISTRY
546.0 J
Tuesday, April 15, 2014 at 9:03pm

Chemistry
For number 1, I was wondering how would you exactly link the structures together? In the form of tris and trans?
Tuesday, April 15, 2014 at 8:36pm

chemistry
Determine ΔSuniv for the following equation: Ca2+ (aq) + SO42- (aq) → CaSO4 (s)
Tuesday, April 15, 2014 at 7:15pm

Chemistry
pH = -log(H^+) Substitute and solve for pH.
Tuesday, April 15, 2014 at 6:28pm

CHEMISTRY HELP !!!!
dGsystem < 0 for any spontaneous process.
Tuesday, April 15, 2014 at 6:27pm

CHEMISTRY HELP !!!!
the following statement is false. Rewrite that it makes a correct statement about free energy. a. ΔGuniverse > 0 for any spontaneous process.
Tuesday, April 15, 2014 at 6:07pm

Chemistry
What is the pH of a solution that has a concentration of hydronium ions that is 1.8 × 10-4 molar H3O+? Show, or explain, the work used to solve this problem.
Tuesday, April 15, 2014 at 5:49pm

chemistry
M of the diluted stuff is 1.14 g/mL x 1000 mL x 0.20 x 1/98 = 2.33M M of the strong stuff is 1.84 x 1000 x 0.98 x 1/98 = 18.4M Then use the dilution formula. mLA x MA = mLB x MB 100 x 2.33 = mLB x 18.4M Solve for mL B. I obtained approx 13 mL
Tuesday, April 15, 2014 at 5:01pm

chemistry
A procedure calls for 100ml of 20% H2SO4, SG=1.14. How much of the concentrated acid (98%), SG=1.84, must be diluted with water to prepare 100ml of acid of the required strength?
Tuesday, April 15, 2014 at 3:54pm

chemistry
mols glyc = grams/molar mass mols H2O = grams/molar mass Xgly = mols gly/total mols XH2O = mols H2O/total mols.
Tuesday, April 15, 2014 at 3:43pm

chemistry
Determine the mole fraction of each substance in a solution containing 36.0g H2O and 46g glycerin, C3H5(OH)3
Tuesday, April 15, 2014 at 3:36pm

chemistry
Use google for conversion 1500 mm Hg = 1.97368421 atm = 199 983.553 pascals
Tuesday, April 15, 2014 at 3:01pm

chemistry
How would I figure out the pressure?
Tuesday, April 15, 2014 at 2:49pm

chemistry
PV = nRT
Tuesday, April 15, 2014 at 2:47pm

Chemistry
I'm not sure what you want for #1. We can't draw structures on this forum_search_20140419. For #2, the Cl outside the coordination sphere is the ionic Cl, therefore Cl- + Ag^+ ==> AgNO3. The two coordinated Cl atoms within the sphere are not ionic and do not react ...
Tuesday, April 15, 2014 at 2:46pm

chemistry
If 1.50mol of oxygen gas exerts a pressure of 1500mmHg at 20∘C, what is the volume in liters?
Tuesday, April 15, 2014 at 2:36pm

Chemistry
1. How would you sketch the probable products of the reaction of the cis and trans with each reagent other than AgNO3? _____ with en _____ with NH3 ____ with KSCN cis: trans: (NOTE: What are the differences between cis and trans and its formation?) 2. How exactly would you ...
Tuesday, April 15, 2014 at 2:15pm

Chemistry
The Eo voltage in tables may changes as a result of acid or basic conditions; however, there are no H or OH ions in the half reactions you've written so you need not worry about that.
Tuesday, April 15, 2014 at 12:31pm

chemistry
What is the "mass you calculated" refer to?
Tuesday, April 15, 2014 at 12:28pm

chemistry
How many mols NaCl do you want? That's M x L = ? Then mols = grams/molar mass. You know molar mass and mols, solve for grams.
Tuesday, April 15, 2014 at 12:12pm

Chemistry
Write and balance the equation. Convert 400.0g C3H8 to mols. mol = grams/molar mass Using the coefficients in the balanced equation, convert mols C3H8 to mols or the product. Now convert mols of the product to volume. mols x 22.4 L/mol = Liters.
Tuesday, April 15, 2014 at 12:12pm

Chemistry
What volume in liters of C3H7Cl is produced if 400.0g of C3H8 (propane) reacts with excess chlorine gas according to the equation C3H8+ Cl2 --> C3H7Cl+HCl
Tuesday, April 15, 2014 at 9:57am

chemistry
what volume of 2.0 M NaCl is required to prepare 150 mL of 0.10 M NaCl?
Tuesday, April 15, 2014 at 9:47am

chemistry
I don't know I copied the question word for word. He wants to know what was produced and percentage changes. I'm sorry
Tuesday, April 15, 2014 at 1:23am

chemistry
What reaction? What change in % did you calculate? I don't get the question?
Tuesday, April 15, 2014 at 12:52am

chemistry
There are two different oxides of copper produced as a result of this reaction. They are copper(I) and copper(II) oxide. If copper is changed to copper(I) oxide the percentage changed in mass is 12%. If copper is changed to copper(II) oxide the percentage change in mass is 25...
Tuesday, April 15, 2014 at 12:32am

chemistry
mols F^- = 0.0025g/atomic mass F and since that is is 1 L, that is the concn in mols/L. Evaluate Qsp and compare with Ksp.
Tuesday, April 15, 2014 at 12:14am

Chemistry, CO2 aq+H2O-&gt;H2CO3!
How many grams of CO2 are needed to neutralize a 5 liters water with a pH of 11 to 7? under the following conditions: P: 4000 psi, T:230 oF Note: CO2 is a one of oil reservoir fluid components with mole percent 0f 3.6%. thanks a million
Monday, April 14, 2014 at 11:54pm

Chemistry
So I multiply Eu3+(aq)+e−→Eu2+(aq) by two so there is two e- in both half reactions. I also remember that I need to add H+ and OH- onto one or both sides depending if the reaction is acid or basic. How do I determine that?
Monday, April 14, 2014 at 11:51pm

chemistry
A ground water source contains 2.5 mg of F- ion per liter. a) what is the concentration of F- ions in moles per liter? b) will CaF2 (Ksp = 2E-10) precipitate when the concentration of Ca2+ = 5.0E-3M?
Monday, April 14, 2014 at 11:16pm

chemistry
(P1V1/T1) = (P2V2/T2) P1 = 1 V1 = 0.550 T1 = 273 P2 = ? V2 = 7.50E-2L T2 = 273 + 20
Monday, April 14, 2014 at 11:13pm

Chemistry
No and partly because I may have led you astray. The numbers I gave you are for 1L of the solution at that concn. You only want 500 mL of that (which I missed on first reading) so you need only 1/2 of your final figure or 5.346/2 = ?.
Monday, April 14, 2014 at 11:10pm

chemistry
A sample of hydrogen chloride gas occupies 0.550L at STP. What is the pressure in atm if the volume is 7.50×10−2L at 20∘C?
Monday, April 14, 2014 at 11:08pm

Chemistry
HAc + NaOH ==> NaAc + H2O First determine the M of the HAc. mL x M = mL x M 22.5 x .21 = 50x (I worked this part for you at your original post yesterday. Apparently you never went back to look at it.) M HAc = approx 0.9 but you need to do it more accurately. Now divide the ...
Monday, April 14, 2014 at 11:04pm

statistics
z-score for chemistry = (82-75)/6.25 = 1.12 z-score for physics = (63-59)/3.57 = 1.12044 I would consider the difference insignificant, so the two scores would be equivalent.
Monday, April 14, 2014 at 11:00pm

Chemistry
I did that but got 5.346 g as my answer. Is that correct?
Monday, April 14, 2014 at 10:57pm

Chemistry
Li3PO4. You want (Li^+) = 0.1385M You want to make this out of Li3PO4. But since Li3PO4 furnishes 3 Li ions for every molecule of Li3PO4, you only need 1/3 that number or 0.1385/3 = ? mols Li3PO4. Then g Li3PO4 = mols x molar mass.
Monday, April 14, 2014 at 10:42pm

Chemistry
CH3COOH + NaOH ==> CH3COONa + H2O mols NaOH = M x L = ? mols CH3COOH = mols NaOH (because of the 1:1 coefficients in the balanced equation.) g CH3COOH = mols CH3COOH x molar mass CH3COOH. Then % CH3COOH = (g CH3COOH/mass sample)*100 = ?
Monday, April 14, 2014 at 10:38pm

Chemistry
This is a limiting reagent (LR) problem. You know that when an amount for BOTH reactants is given. Zn + 2HCl ==> H2 + ZnCl2 mols Zn = grams/molar mass. mols HCl = M x L = ? Using the coefficients in the balanced equation, convert mols Zn to mols H2. Do the same for mols HCl...
Monday, April 14, 2014 at 10:35pm

Chemistry
Thanks for your help. Sorry, I accidentally posted the question again without meaning to.
Monday, April 14, 2014 at 10:32pm

General Chemistry
Thanks for your help! I got it now. I messed up with second half reaction, it was supposed to be Cr^2+ + 2e- -> Cr; E = -0.91.
Monday, April 14, 2014 at 10:32pm

statistics
Leslie took two midterm exams and earned the following scores: 82 on the chemistry exam (class distribution: μ = 75, σ = 6.25) and 63 on the physics exam (class distribution: μ = 59, σ = 3.57). Rounding to two decimal points, on which exam should Leslie get...
Monday, April 14, 2014 at 10:27pm

Chemistry
If that is the smallest Ecell, then turn those half cells into a reaction. Arrange the half cells so they produce a positive voltage. 2Eu^2+ + Sn^2+ ==> 2Eu^3+ + Sn
Monday, April 14, 2014 at 10:25pm

Chemistry
What mass of lithium phosphate is needed to prepare 500.0 mL of a solution having a lithium ion concentration of 0.1385 M?
Monday, April 14, 2014 at 10:21pm

Chemistry
2Fe3+(aq)+H2(g)→2Fe2+(aq)+2H+(aq).​ Ecell = Eocell - (0.5916/2*log Q and I know that confuses you but don't be. Plug in the numbers Eo and n and for Q plug in concns/pressures(in atm) as follows: Q = [(H^)^2*(Fe^2+)^2]/[(Fe^3+)^2*pH2] I write it this way ...
Monday, April 14, 2014 at 10:18pm

Chemistry
Vinegar is a solution of acetic acid, CH3COOH, dissolved in water. A 4.69 g sample of vinegar was neutralized by 32.97 mL of 0.100 M NaOH. What is the percent by weight of acetic acid in the vinegar?
Monday, April 14, 2014 at 10:18pm

Pages: <<Prev | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>

Post a New Question | Current Questions

Homework Help: Science

Search
Members