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April 18, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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Chemistry
hahahha
Sunday, March 16, 2014 at 4:44am

chemistry
k
Sunday, March 16, 2014 at 3:33am

Chemistry (titrations)
Yes they are in the 1:1 ratio. 1.8E-4 mols EDTA = 1.8E-4 mols Fe 1.8E-4 mols Fe x atomic mass Fe = grams Fe. Thus you have that many grams Fe in 50 g (50 mL solution) = 2.01E-4 g/g or 201 g/1 million grams = 201 ppm.
Sunday, March 16, 2014 at 12:19am

Chemistry (titrations)
15.00 mL of 0.01200 M EDTA were used to titrate 50 mL aliquot solution containing iron (II). How much iron (II) is present in the solution? The answer in the book is 201 ppm. I tried getting the moles of EDTA (n,EDTA = 1.8 x 10^-4 mol). I think they're in 1:1 ratio, or I ...
Saturday, March 15, 2014 at 10:59pm

Chemistry
Calculate the amount of energy released per gram of nuclei when 2 protium nuclei react to form deuterium nucleus (protium = 1.00782 amu, deuterium = 2.01410 amu). The answer in the book is -2.0 x 10^10 J, but I don't have any idea on how to do this. Please help, and thank ...
Saturday, March 15, 2014 at 10:39pm

incomplete--chemistry

Saturday, March 15, 2014 at 9:49pm

chemistry
This is just another stoichiometry problem but since everything is a gas and measured at the same conditions, it allows us to use a shortcut. C3H8 + 5O2 ==> 3CO2 + 4H2O We may use volume in liters as if L = mols. Simply convert L C3H8 to L CO2 using the coefficients in the ...
Saturday, March 15, 2014 at 9:47pm

chemistry
Assuming that the volumes of carbon diox- ide and of propane are measured under the same experimental conditions, what volume of carbon dioxide is produced by the complete combustion of 20 L of propane? i just dont understand
Saturday, March 15, 2014 at 9:38pm

chemistry
The distance versus time plot for a particular object shows a quadratic relationship. Which column of distance data is possible for this situation?
Saturday, March 15, 2014 at 8:11pm

Chemistry
How do you figure it out? That's what I'm asking.
Saturday, March 15, 2014 at 6:06pm

chemistry
Use the Henderson-Hasselbalch equation.
Saturday, March 15, 2014 at 5:51pm

chemistry
Ba(OH)2 + 2HCl ==> BaCl2 + 2H2O Mols Ba(OH)2 = M x L = approx 0.012 mols HC = twice that (look at the coefficients in the balanced equation. HCl = appox 0.024 Then mol = M x L. You know M and mols, solve for L.
Saturday, March 15, 2014 at 5:49pm

chemistry
Calculate the pH for the hydrogen half-cell of the following voltaic cell if the observed cell voltage is 1.00 V. Mn|Mn2+(1.00 M)||H+(pH =?), H2(1.00 atm)|Pt
Saturday, March 15, 2014 at 5:43pm

Chemistry
hi
Saturday, March 15, 2014 at 5:31pm

Chemistry
Nacl(l)
Saturday, March 15, 2014 at 5:23pm

Chemistry
CuCl2+2NH4OH=2NH4Cl+Cu(OH)2
Saturday, March 15, 2014 at 4:29pm

Science (Chemistry)
The answers all are in google. we are not here to do your homework. look it up before posting here.
Saturday, March 15, 2014 at 6:41am

Chemistry
a.) 102 b.) 64 c.) 198 d.) 34 Please check them
Saturday, March 15, 2014 at 6:40am

chemistry
Determine the volume of 1.2 mol/L HCl that will be required to neutralize 150 mL of 0.080 mol/L Ba(OH)2
Saturday, March 15, 2014 at 3:50am

chemistry
3. a) Calculate the pH of the buffer solution prepared by mixing 40.0 mL of 0.100 M H3PO4 and 60.0 mL of 0.100 M KH2PO4. Given the pKa of H3PO4 is 2.12.
Saturday, March 15, 2014 at 12:01am

Science (Chemistry)
. Complete all the following for the reaction (NH4)2S + Cd(NO3)2 --> CdS(s) + NH4NO3 1. Balance this equation 2. Write the ionic equation 3. Write the net ionic equation
Friday, March 14, 2014 at 10:00pm

Chemistry
I have to go to work this weekend so I'm trying to get my homework finished. Could you please help me figure out this question? Calculate the mass of 1.00 mol of each of these substances: a.) silicon dioxide (SiO2) b.) diatomic nitrogen (N2) c.) iron (|||) hydroxide (Fe(OH...
Friday, March 14, 2014 at 9:54pm

Chemistry
half the concentration means twice the volume. so, add another 600.0 mL of H2O
Friday, March 14, 2014 at 9:21pm

chemistry 101
PBr3 is 271 grams per Mol Br is 80 g /mol so Br3 is 240 g/mol (240/271)1.57 = 1.39 grams
Friday, March 14, 2014 at 8:29pm

chemistry 101
How many grams of bromine are in 1.57 grams of phosphorus tribromide?
Friday, March 14, 2014 at 8:18pm

chemistry
2742500
Friday, March 14, 2014 at 7:50pm

Chemistry, please help!!!
I have to go to work this weekend so I'm trying to get my homework finished. Could you please help me figure out this question? Calculate the mass of 1.00 mol of each of these substances: a.) silicon dioxide (SiO2) b.) diatomic nitrogen (N2) c.) iron (|||) hydroxide (Fe(OH...
Friday, March 14, 2014 at 6:34pm

Chemistry
Calculate the mass of 1.00 mol of each of these substances: a.) silicon dioxide (SiO2) b.) diatomic nitrogen (N2) c.) iron (|||) hydroxide (Fe(OH)3) d.) copper (Cu)
Friday, March 14, 2014 at 5:10pm

chemistry
Roses are red Violets are blue Sorry to be playing on this page But I don't have a clue.
Friday, March 14, 2014 at 4:48pm

Chemistry
When the rate of the reaction 2NO+O2=2NO2 was studied, the rate was found to double when the O2 concentration alone was doubled but to quadruple when the NO concentration alone was doubled. Which of the following mechanisms accounts for these observations? a.) Step 1: NO + O2=...
Friday, March 14, 2014 at 3:10pm

Chemistry
In a bomb calorimeter, a 6.50 g sample of octane (C8H18) is combusted. The combustion enthalpy for octane is -5.45 MJ per mol C8H18. The temperature change of the calorimeter is 16.5 oC. What is the heat capacity of the calorimeter?
Friday, March 14, 2014 at 3:09pm

Chemistry
Determine the rate constant for the following second-order reaction: A=C+2D given that the initial concentration of A is .3 M and that the concentration of C increase to .01 M in 200 seconds. Express the result in terms of the rate law for the loss of A.
Friday, March 14, 2014 at 3:05pm

Chemistry
How much water can be produced from the complete reaction of 3.64 L of oxygen gas, at STP, with hydrogen gas? Answer in units of g
Friday, March 14, 2014 at 2:22pm

Chemistry
Uranium benefits and uses
Friday, March 14, 2014 at 1:52pm

Chemistry
Uranium 235 problem that exits
Friday, March 14, 2014 at 1:51pm

Chemistry
how many grams of bromine will be present in a sample that molar mass of 70.0 g/mol and occupies a 2.00L container at 117 kPa and 35.1C
Friday, March 14, 2014 at 1:28pm

Chemistry
A student has 600.0 mL of a 0.30M solution of HNO3. How much water must she add in order to make it a 0.15 M solution? Be careful how this question is answered.
Friday, March 14, 2014 at 1:07pm

chemistry
Five liters of air at -50.0°C are warmed to 100.0°C. What is the new volume if the pressure remains constant?
Friday, March 14, 2014 at 12:30pm

chemistry
In standardizing a potassium hydroxide solution, a student finds that 32.60mL of the base solution is needed to titrate 0.5045 grams of KHP to a phenolphthalein end point. In another titration, 26.63mL of this same base solution is needed to titrate 0.2003grams of an unknown ...
Friday, March 14, 2014 at 11:53am

chemistry
Calculate the molarity if a Ba(OH)2 solution if a 37.25ml portion of this solution is neutralized by 45.00mL of 1.500M HCl. You will need the balanced reaction
Friday, March 14, 2014 at 11:49am

chemistry
A radioactive sample contains 2.45 g of an isotope with a half-life of 3.8 days. How much of the isotope in grams will remain after 11.4 days?
Friday, March 14, 2014 at 10:40am

Chemistry
How many grams of I2 are present in a solution if 39.85mL of 0.160M Na2S2O3 solution is needed to titrate the I2 Solution
Friday, March 14, 2014 at 1:43am

Chemistry
pKa=-log(Ka) Then to find pH use, pKa+log(0.220/0.220) Thus, pH=pKa
Thursday, March 13, 2014 at 11:13pm

Chemistry
hhjshjksdhasd
Thursday, March 13, 2014 at 11:08pm

Chemistry
How many grams of a 17.7% potassium sulfate solution would contain 419.9 g potassium sulfate? Answer in units of g
Thursday, March 13, 2014 at 10:50pm

Chemistry
Write the equation for the dissolution of NH4NO3 in water. If 5.95 mol of NH4NO3 are dissolved, how many total moles of ions are produced? Answer in units of mol
Thursday, March 13, 2014 at 10:48pm

Chemistry
How many moles of ammonia gas can be formed from the complete reaction of 44.8 liters of nitrogen gas at standard temperature and pressure (STP), according to the balanced equation, N2 (g) + 3H2 (g) arrow 2NH3 (g)?
Thursday, March 13, 2014 at 10:00pm

Chemistry
Express the concentration of a commercial hydrogen peroxide solution, which is 3.0 (w/w), as a molarity. Show all work
Thursday, March 13, 2014 at 10:00pm

chemistry
Can u show the solution to this problem? What is the mass of silver that can be prepared for 1.00g of copper metal Cu (s)+2AgNO3(ag)= Cu(NO3)2(ag)+2Ag(s)
Thursday, March 13, 2014 at 9:49pm

Chemistry
What are the molality and mole fraction of solute in a 32.3 percent by mass aqueous solution of methanol (CH3OH)? molality = ?m mole fraction =
Thursday, March 13, 2014 at 8:28pm

Chemistry
What is the mole fraction of NaOH in an aqueous solution that contains 33.4% NaOH by mass?
Thursday, March 13, 2014 at 8:21pm

Chemistry Help Please
1)how would the accuracy of your determined keq change if all your volume measurements were made with graduated cylinders rather than pipets ? 2) if all of the SCN^- was not converted completely to FeNCS^2+ when the calibration curve was prepared would this raise or lower the ...
Thursday, March 13, 2014 at 7:36pm

Chemistry
The data below has been taken for the reaction of a dye with the hydroxide ion. The reaction was performed at two different hydroxide ion concentrations while the dye concentration was kept constant. What is the rate law? [OH─] = 0.10 M [OH─] = 0.20 M t (min) Abs ...
Thursday, March 13, 2014 at 7:32pm

CHEMISTRY.
what would be the VSEPR shape of pyridine?
Thursday, March 13, 2014 at 6:01pm

chemistry
A student decomposes water to produce hydrogen and oxygen. If the student begins with 34.7 g of water and collects 24.9 g of oxygen, what is her percent yield?
Thursday, March 13, 2014 at 3:02pm

Chemistry
I tried working this question out with the help already provided, but I couldn't ever get the right answer. If you could possibly explain how to do the problem step by step and include the right answer, I'd greatly appreciate it. Thanks! What mass of sodium benzoate ...
Thursday, March 13, 2014 at 2:46pm

Chemistry
This must be a multipart question sincer the Kc data for HCl is not relevant. You have 2ICl ==> I2 + Cl2 and you want the reverse of that. Just take the reciprocal of Kc for the forward rxn or Kc reverse = 1/Kc forward
Thursday, March 13, 2014 at 12:32pm

chemistry
16.172 grams
Thursday, March 13, 2014 at 12:31pm

Chemistry
Based on these data I would go with AgCl(least soluble), NaCl, KCl(most soluble) with the idea being it takes less energy to break the crystal bonds for KCl and most to break the crystal bonds for AgCl. I think the actual solubilities are NaCl most and AgCl least.
Thursday, March 13, 2014 at 12:27pm

chemistry
When reacted with H2O? 2Na + 2H2O ==> 2NaOH + H2 mols H2 you want = 781g/molar mass H2. Using the coefficients in the balanced erquation, convert mols H2 you want to mols Na to start. Then convert mols Na to g. grams = mols x atomic mass Na.
Thursday, March 13, 2014 at 12:08pm

chemistry
You want 23.1% w/w which means 23.1 g urea in 100 grams solution. (1.6/x)*100 = 23.1 Solve for x for TOTAL mass. I obtained about 7 g total (only approximate--you need to do it more accurately)--so you want about 7-1.6 = ? g H2O
Thursday, March 13, 2014 at 12:04pm

Chemistry
See your post above.
Thursday, March 13, 2014 at 11:59am

Chemistry
http://en.wikipedia.org/wiki/Silicon_car​bide
Thursday, March 13, 2014 at 11:59am

Chemistry
what is chemical equation for the preparation of siliconcarbide
Thursday, March 13, 2014 at 10:57am

Chemistry
what is chemical for the preparation of siliconcarbide
Thursday, March 13, 2014 at 10:47am

chemistry
if I have 1.60g of urea, how much water, in grams, should be added in the preparation of a 23.1 percent by mass solution?
Thursday, March 13, 2014 at 10:32am

chemistry
how many grams of sodium metal are needed to give 781 g of hydrogen?
Thursday, March 13, 2014 at 8:28am

Chemistry
The lattice enthalpies of NACL KCL and AGCL are 787,717 and 916 kj/mol; based on these values , arrange them in increasing order of water solubility and expain the answer.
Thursday, March 13, 2014 at 3:20am

Chemistry
The equilibrium constant Kc^i is 3.2x10^-34 at 25 degrees C for 2HCl(g) -> H2(g) + Cl2 (g). The equilibrium constant Kc^ii is .10 at 25 degrees C for 2ICl (g) -> Cl2 (g) + I2 (g). a) Calculate the equilibrium constant Kc for the reaction below at 25 C Cl2(g) + I2 (g) -&...
Thursday, March 13, 2014 at 2:37am

Chemistry
Supposing all the "gas" is water vapor. The source below gives the specific heat of water vapor and liquid water: (2.000 J/(g·°C) x ((0.07796 g) x (125 ºC - 100 ºC) = 3.898 J from cooling the vapor to 100 ºC (0.07796 g H2O) / (18.01532 g H2O...
Thursday, March 13, 2014 at 2:15am

Chemistry
10
Thursday, March 13, 2014 at 1:51am

chemistry
higher concentration
Thursday, March 13, 2014 at 1:26am

Chemistry 32
mols = grams/molar mass M = mols/L solution pH = -log(Molarity HCl) I get pH = 1
Thursday, March 13, 2014 at 12:12am

Chemistry 32
HCI (aq) is a strong acid. suppose you dissolved 0.0365 grams of HCI in water to give a final volume of 10.0 mL. what is the pH of this final solution. The molar mass of HCU is 36.5g /mole and the molar mass of water is 18.0g/mole
Wednesday, March 12, 2014 at 11:25pm

Chemistry
This topic's pretty old, but I figured it would be worth it to have the new way to solve the problem posted as well. If you're like me you're a young whippersnapper who's never even heard of normality. It's actually not as hard as DrBob says. Molarity = ...
Wednesday, March 12, 2014 at 11:17pm

CHEMISTRY.
what would be the VSEPR shape of pyridine?
Wednesday, March 12, 2014 at 10:26pm

chemistry
1. How many different 4p orbitals are there? 2. How many radial nodes are there? 3. How many angular nodes are there? (excluding the radial nodes) I thought it was 2,1, 2??
Wednesday, March 12, 2014 at 9:53pm

chemistry
Thank you!! You are so helpful!
Wednesday, March 12, 2014 at 9:52pm

chemistry
The maximum number of electrons in ANY d orbital is 10. The maximum number of electrons in any shell is 2N^2. 72 is right but 22 is wrong.
Wednesday, March 12, 2014 at 9:51pm

chemistry
no, there is no diagram. they just say it: 8p1 is the orbital number. So n=8. but i'm stuck from there. Thank you for your help.
Wednesday, March 12, 2014 at 9:51pm

chemistry
wavelength = h/mv Substitute and solve for v. Don't forget to change wavelength to m.
Wednesday, March 12, 2014 at 9:48pm

chemistry
Do you have a diagram from which to choose or are you to calculate the wavelength. Is that 8p1 a term symbol or something different?
Wednesday, March 12, 2014 at 9:47pm

chemistry
dE = 2.18E-18 J*(1/16 - 1/81) c = freq x wavelength = 3E8 m/s
Wednesday, March 12, 2014 at 9:43pm

chemistry
E = hc/wavelength E = must be in J/photon; therefore, 1350000/6.02E23 = E Then fill in h, c and solve for wavelength and convert to nm.
Wednesday, March 12, 2014 at 9:35pm

chemistry
1. it takes: ____ electrons to fill the 6d subshell of an atom. 2. It takes _____ electrons to fill the n=6 shell of an atom. I thought it was 22 and 72?
Wednesday, March 12, 2014 at 9:26pm

chemistry
What is the velocity, in meters per second, of a beam of electrons if they are to display a "de Broglie" wavelength of 41.2 um?
Wednesday, March 12, 2014 at 9:24pm

Chemistry
Thank you Batman. I am forever in your debt. And thanks my friendly neighborhood Spiderman for helping me understand!
Wednesday, March 12, 2014 at 9:21pm

chemistry
What is the longest wavelength of light that can be emitted by a hydrogen atom that has an initial configuration of 8p^1? Thank you!!
Wednesday, March 12, 2014 at 9:18pm

chemistry
What is (delta E) for the traansition of an electron from n=9 to n=4 in a Bohr hydrogen atom? What is the frequency? Thank you!
Wednesday, March 12, 2014 at 9:17pm

chemistry
What is the wavelength, in nm, of light with an energy content of (1.35x10^3 kJ/mol)? Thank you!!!
Wednesday, March 12, 2014 at 9:16pm

incomplete--chemistry

Wednesday, March 12, 2014 at 8:27pm

Chemistry
Frankly, I've never seen this before but if I had to name it I would write sulfur(II) chlorate Sulfur has common valencies of -2, 0, +4 and +6; the (II) is to denote a valence (oxidation state) of +2.
Wednesday, March 12, 2014 at 8:24pm

chemistry
Arrange the three metals in order of their relative strengths as reducing agents, placing the strongest first. Write each metal as a half reaction.
Wednesday, March 12, 2014 at 7:46pm

chemistry
what is the chemical reactions for these... 2Na+2H2O->2NaOH+H2 2FeS2+3O2->Fe2O2+2SO2 CaCO3->CO2+CaO
Wednesday, March 12, 2014 at 7:15pm

Chemistry
Sulfur chlorate I suppose
Wednesday, March 12, 2014 at 6:32pm

Chemistry
how do i name this chemical? S(ClO3)2
Wednesday, March 12, 2014 at 6:09pm

Chemistry
although what Steve said is fine.
Wednesday, March 12, 2014 at 5:58pm

Chemistry
Ferrous Nitrate (Iron+2) Fe(NO3)2 Ferric Nitrate (Iron +3) Fe(NO3)3
Wednesday, March 12, 2014 at 5:57pm

Chemistry
It'd be Iron Nitrate, but more precisely, Iron (II) Nitrate
Wednesday, March 12, 2014 at 5:56pm

Chemistry
how do i name this chemical? Fe(NO3)2
Wednesday, March 12, 2014 at 5:24pm

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