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April 21, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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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

Chemistry
what is the answer....
Wednesday, March 12, 2014 at 3:24pm

Chemistry
I don't believe the equilibrium is shifted by pressure in an all aqueous system although I have a little trouble visualizing varsol as an all aqueous phase.
Wednesday, March 12, 2014 at 3:22pm

Chemistry
wrong, sir. it is not the ksp...gosh how stupid.
Wednesday, March 12, 2014 at 3:19pm

Chemistry
its not though. i put that and it was wrong...
Wednesday, March 12, 2014 at 3:16pm

Chemistry
Here is a site that lists ranges for hardness etc. Scroll down about half way on the page for the table. http://en.wikipedia.org/wiki/Hard_water
Wednesday, March 12, 2014 at 3:08pm

Chemistry
CO2
Wednesday, March 12, 2014 at 3:03pm

Chemistry
3.5M x (11.6 mL/214.8 mL) = ? or use the dilution formula of c1v1 = c2v2 3.5 x 11.6 = c2 x 214.8
Wednesday, March 12, 2014 at 3:03pm

chemistry
per kg of solvent.
Wednesday, March 12, 2014 at 2:59pm

Chemistry
Look at your stoichiometry problem above. This is done the same way.
Wednesday, March 12, 2014 at 2:58pm

Chemistry
Cu + 2AgNO3 ==> 2Ag + Cu(NO3)2 mols Cu = grams/atomic mass Using the coefficients in the balanced equation, convert mols Cu to mols Ag. Now convert mols Ag to grams Ag. g = mols x atomic mass Ag This is the theoretical yield.
Wednesday, March 12, 2014 at 2:58pm

Chemistry
what is it supposed to be?
Wednesday, March 12, 2014 at 2:39pm

Chemistry
i got it wrong... i got 1.22x10^-32. help!
Wednesday, March 12, 2014 at 2:38pm

Chemistry
If 6.51g of copper is reacted with 28.4g of silver nitrate, the products will be copper (II) nitrate and silver metal. What is the theoretical mass of silver that will be produced??
Wednesday, March 12, 2014 at 1:47pm

Chemistry
The reaction between 32.0g of CH4 and excess oxygen gas produces 75.9 of CO2 gas and some water. Determine the percent yield? Plss help :((
Wednesday, March 12, 2014 at 1:46pm

chemistry
Molality is a unit of concentration that measures the moles of solute per
Wednesday, March 12, 2014 at 1:26pm

STATISTIC HELP
1.M&M candies are great for probability. The following tables are the color distributions for the candies. Fill in each table with the missing probability and answer the questions that follow. Plain Brown Blue Green Orange Red Yellow Probability 0.3 0.1 0.1 0.1 0.02 ??? ...
Wednesday, March 12, 2014 at 1:08pm

Chemistry
If you dilute 11.6 mL of a 3.5 M solution to make 214.8 mL of solution, what is the molarity of the dilute solution?
Wednesday, March 12, 2014 at 12:28pm

chemistry
i don't know how to write it into a chemical formula
Wednesday, March 12, 2014 at 11:51am

AP CHEMISTRY
[Cd(bipy)_2]Cl_
Wednesday, March 12, 2014 at 11:39am

AP CHEMISTRY
[Cd(bipy)_2]Cl_
Wednesday, March 12, 2014 at 11:38am

Chemistry
What are the typical ppm values of hard water and an unknown water sample and how do their titrations compare?
Wednesday, March 12, 2014 at 3:13am

Chemistry
How would applying an external pressure on the following equilibrium affects the distribution of iodide between the polar (aqueous) and non polar (varsol) phases? I2+I^- --> I3^- All are aqueous solutions
Wednesday, March 12, 2014 at 1:33am

7th Grade
In my school, we have three units for seventh grade: Chemistry, Physics, & Astronomy. If you want to know your personal science class curriculum, ask your teacher! Hope I helped! ~Sanja
Wednesday, March 12, 2014 at 1:30am

Chemistry
Sorry. I just want to be sure that I am doing it right.
Wednesday, March 12, 2014 at 12:13am

Chemistry II
This question looks answered it looks as if the final answer is 128kJ/mol is it?
Tuesday, March 11, 2014 at 11:45pm

chemistry
a 151g quantity of water at 30.0 celsius was heated to boiling and 35.0 g of that water was converted to steam. what is the heat input required in calories to do this?
Tuesday, March 11, 2014 at 11:42pm

Chemistry
I answered the first part for you but you may not have liked it. Most (and some prof too I think) believe dissolved CO2 affect the value for M NaOH no matter what. The anhydride (anhydride means without water) of an acid is a material which produces that acid when added to ...
Tuesday, March 11, 2014 at 11:13pm

Chemistry
4536
Tuesday, March 11, 2014 at 11:10pm

Chemistry
You must kidding? If you know how to do one of these you know how to do them all.
Tuesday, March 11, 2014 at 11:02pm

Chemistry
What's wrong with pH = -log(H3O^+)?
Tuesday, March 11, 2014 at 11:00pm

Chemistry
3. How does dissolved CO2 in distilled water affect the accuracy of the determination of a NaOH solution's concentration? The CO2 in the distilled water will create a more acidic solution which will affct the determination of NaOH solution's concentration? How is the ...
Tuesday, March 11, 2014 at 10:59pm

Chemistry
yes
Tuesday, March 11, 2014 at 10:58pm

Chemistry
Determine the pH of a 1.2×10^−2 M solution
Tuesday, March 11, 2014 at 10:55pm

Chemistry
What is the pH of a solution whose [H3O+] is 9.2× 10^−9 M?
Tuesday, March 11, 2014 at 10:55pm

Chemistry
Do I use: pH= -log[h30+]
Tuesday, March 11, 2014 at 10:52pm

Chemistry
Thamks! How do I determine the pH value of this solution?
Tuesday, March 11, 2014 at 10:46pm

Chemistry Urgent
Read your post below.
Tuesday, March 11, 2014 at 10:41pm

Chemistry Urgent
Do you want enthalpy/grams or enthalpy/mol. Most prefer it to be kJ/mol. q = g H2O x specific heat H2O x (Tfinal-Tinitial) That gives you q/2.30g X = ? J/g If you want J/mol it is J/g x 82.0 = ? J/mol. You can change that to kJ/mol if you wish.
Tuesday, March 11, 2014 at 10:40pm

Chemistry Urgent
95.0mL of H2O is initially at room temperature (22.0∘C ). A chilled steel rod at 2.0∘C is placed in the water. If the final temperature of the system is 21.3∘C , what is the mass of the steel bar? Specific heat of water = 4.18 J/g⋅∘C Specific heat...
Tuesday, March 11, 2014 at 10:38pm

chemistry
heat gained by rod + heat lost by H2O = 0 [mass rod x specific heat rod x (Tfinal-Tinitial)] + [mass H2O x specific heat H2O x (Tfinal-Tinitial)] = 0 Substitute and solve for mass rod
Tuesday, March 11, 2014 at 10:35pm

Chemistry Urgent
A calorimeter contains 32.0mL of water at 13.0∘C . When 2.30g of X (a substance with a molar mass of 82.0g/mol is added, it dissolves via the reaction X(s)+H2O(l)¨X(aq) and the temperature of the solution increases to 30.0∘C . Calculate the enthalpy ...
Tuesday, March 11, 2014 at 10:35pm

Chemistry
Since HCl is a strong acid (meaning it ionizes 100%), then (H^+) = (HCl). If you want to know OH and you have H^+, use (H^+)(OH^-) = Kw = 1E-14
Tuesday, March 11, 2014 at 10:33pm

chemistry
I think 1 is right. I disagree with 2. Yes, the solution of NaOH M is too low since all of the NaOH has not dissolved but during the second titration the NaOH is stronger which means it takes less NaOH than it should and M = mmols/mL so smaller NaOH mL means a larger M. 3. The...
Tuesday, March 11, 2014 at 10:29pm

chemistry
95.0mLmL of H2O\rm H_2O is initially at room temperature (22.0∘C\rm{} ^{\circ}C). A chilled steel rod at 2.0∘C\rm ^{\circ}C is placed in the water. If the final temperature of the system is 21.3∘C^{\circ}C, what is the mass of the steel bar? Specific heat of ...
Tuesday, March 11, 2014 at 10:28pm

Chemistry
A solution contains 0.00245 M HCl. Determine the [H3O+] for the solution. points Determine the [OH-]
Tuesday, March 11, 2014 at 10:23pm

Chemistry
HCl + NaOH --- > H2O + NaCl balanced as is One mole of NaOH for every one mole of HCl because the equation balances with one of each .68 * .29 = .1972 moles of HCl so we need .1972 moles of NaOH
Tuesday, March 11, 2014 at 9:47pm

Chemistry
In neutralization reactions, acid + base ¨ salt + water HCl can be neutralized with NaOH. How many moles of NaOH will it take to neutralize 0.68 L of 0.29 M HCl? Is there a formula that I need to use here?
Tuesday, March 11, 2014 at 9:39pm

Chemistry
That's a lot of significant figures you are quoting.
Tuesday, March 11, 2014 at 9:39pm

Chemistry
Substitute the numbers into the Henderson-Hasselbalch equation and calculate the ratio of (base)/(acid). That will tell you whatever you need to know about the ratio.
Tuesday, March 11, 2014 at 9:36pm

Chemistry
Thank You!! I got it right! My answer is 22.10853.
Tuesday, March 11, 2014 at 9:36pm

Chemistry
Actually, there isn't enough information to answer the question. The below will calculate the volume of NaOH required to reach the EQUIVALENCE POINT (which I assume is what the problem wants). The problem asks, however, mL required to read the END POINT. The end point ...
Tuesday, March 11, 2014 at 9:32pm

chemistry
A solution prepared by mixing 16.7 mL of 0.760 M NaCl and 16.7 mL of 0.760 M KI was titrated with 0.380 M AgNO3 in a cell containing a silver indicator electrode and a saturated calomel reference electrode. (a) What is [Ag+] when 16.2 mL of 0.380 M AgNO3 have been added? ...
Tuesday, March 11, 2014 at 9:30pm

chemistry
Plot the data as pH on the y axis and mL on the x axis. Locate the equivalence point, read the mL, divide that by 2 and read the pH at that mL mark (the mL/2 mark that is) and that will be the pKa value for the weak acid.
Tuesday, March 11, 2014 at 9:26pm

chemistry
You need to rephrase this question. You have CuSO4.5H2O produced but it is a reactant. And I don't see where you have any glycine at all.
Tuesday, March 11, 2014 at 9:23pm

Chemistry
You do them step by step. I use units I have memorized; sometimes that means going around the house more times to get where I'm going but it keeps me from memorizing a book of conversion factors. 3.50 mi/hr to yards/min. I remember there are 5,280 feet/mi There are 3 feet/...
Tuesday, March 11, 2014 at 9:16pm

Chemistry
You have a vinegar solution you believe to be 0.8 M. You are going to titrate 21.39 mL of it with a NaOH solution that you know to be 0.774 M. At what volume of added NaOH solution would you expect to see an end point? Answer in units of mL
Tuesday, March 11, 2014 at 9:07pm

Chemistry
delta x (position) = h/4*pi*mdeltav. delta x = h you know 4*pi you know mass = 247 lb converted to kg. delta v is 17.09 x 0.1 m/hr conerted to m/s. Here is a site that does a pretty good job of explaining how to do this. I've also included another site that helps, too. ...
Tuesday, March 11, 2014 at 9:02pm

Chemistry check and help
See your post above.
Tuesday, March 11, 2014 at 8:22pm

Chemistry
Pb(NO3)2 + Na2SO4 ==> Divide this into Pb(NO3) is Pb + element; NO3^- - element. Na2SO4 is Na + element; SO4^2- l element. + of #1 goes with - of #2 + of #2 goes with - of #1. (Actually, I think that's the hard way to do it; you just change partners between the two ...
Tuesday, March 11, 2014 at 8:21pm

chemistry
The first two are right. Silver ION is Ag^+. Ag is silver metal. Plumbous bromite is Pb(BrO2)2 Plumbous makes it +2 valence instead of +4. Bromite is BrO2^- I might be able to help with the first part of your question if I knew what the problem is.
Tuesday, March 11, 2014 at 8:16pm

Chemistry
See your posts above.
Tuesday, March 11, 2014 at 8:09pm

Chemistry
At pH 3.85, which of the following is true? A.[lactic acid] > [lactate ion] B.[lactic acid] < [lactate ion] C.[lactic acid] = [lactate ion] At pH 11.61, which of the following is true? A.[lactic acid] = [lactate ion] B.[lactic acid] < [lactate ion] C.[lactic acid] &...
Tuesday, March 11, 2014 at 8:09pm

Chemistry
If you know H^+ or OH^- the other can be calculated from (H^+)(OH^-) = Kw = 1E-14 If you want pH pH = -log(H^+) If you want pOH pOH = -log(OH^-) If yo have pH or pOH and want the other one pH + pOH = pKw = 14
Tuesday, March 11, 2014 at 8:08pm

Chemistry
Sometimes the basicity of a solution is reported using pOH (pOH = -log[OH-]). What is the a. [OH-] if pOH = 1.90 b. [H3O+] if pOH = 12.94 c. pH if pOH = 9.70
Tuesday, March 11, 2014 at 7:30pm

Chemistry
Calculate the H3O+ concentration present in water under the following conditions. Enter your answer in scientific notation. [OH-] = 2.8 x 10-7 M [OH-] = 8.8 x 10-3 M [OH-] = 2.4 x 10-11 M
Tuesday, March 11, 2014 at 7:23pm

chemistry
i need help with writing nomenclature for the formula and the compounds examples: Sodium bisulphate hydroiodic acid ammonium dihydrogen phosphate Zn(HCrO4)2 Calcium metal ferrous bromide sodium carbide phosphate radical liquid mercury plumbic oxide auric carbonite sodium ...
Tuesday, March 11, 2014 at 6:57pm

Chemistry
Thermochemistry Essay Rough Draft
Tuesday, March 11, 2014 at 6:10pm

Chemistry
A student walks at a brisk 3.50 mi/hr. Calculate the student's speed in yards/minute. I have 4 questions just like this one. Could you tell me step by step on how to do the double conversions? Thanks!
Tuesday, March 11, 2014 at 5:12pm

Chemistry check and help
what is ... Sodium bisulphate hydroiodic acid ammonium dihydrogen phosphate Zn(HCrO4)2 Calcium metal ferrous bromide sodium carbide phosphate radical Check... sodium bicarbonate NaHCO3
Tuesday, March 11, 2014 at 4:45pm

Chemistry
A 247 lb fullback runs the 40 yd dash at a speed of 17.09 ± 0.1 mi/h. (a) What is his de Broglie wavelength (in meters)? (b) What is the uncertainty in his position? ** I found part A but I am unsure how to use this information to get part B. Any help is appreciated :)
Tuesday, March 11, 2014 at 4:44pm

Chemistry
A student walks at a brisk 3.50 mi/hr. Calculate the student's speed in yards/minute. I have 4 questions just like this one. Could you tell me step by step on how to do the double conversions? Thanks!
Tuesday, March 11, 2014 at 4:41pm

chemistry
cuso4.5h20 + 2c2h5no2 = cu(gly)2.h20 moles of cuso4.5h2o produced is 12mmoles moles of glycine poriduced is 16.5 mmoles. which is the limiting reagent?
Tuesday, March 11, 2014 at 4:29pm

chemistry
A 125.0 mg sample of an unknown, monoprotic acid was dissolved in 100.0 mL of distilled water and titrated with a 0.050 M solution of NaOH. The pH of the solution was monitored throughout the titration, and the following data were collected. Determine the Ka of the acid. ...
Tuesday, March 11, 2014 at 3:22pm

Chemistry: Freezing point depression
mols EtOH = grams/molar mass m = mols EtOH/kg solvent delta T = Kf*m Subract delta T from zero to find nw freezing point.
Tuesday, March 11, 2014 at 12:52pm

Chemistry
8N2O4 + S8 + 8H2O ==> 8H2SO3 + 16NO
Tuesday, March 11, 2014 at 12:47pm

Chemistry - incomplete
A good first step would be to get some H on the left . . .
Tuesday, March 11, 2014 at 12:12pm

chemistry
q = mass Pt x specific heat Pt x (Tfinal-Tinitial) 20.7 = 11.0 x sp.h. x (35.8 - 20.5) sp.h. = ?
Tuesday, March 11, 2014 at 12:10pm

Statistic Please Check
Check this out please Thanks Lesson 3 Unit 2 Probability Couplements, Disjoint Events and the addition Rule 1.M&M candies are great for probability. The following tables are the color distributions for the candies. Fill in each table with the missing probability and answer the...
Tuesday, March 11, 2014 at 11:44am

chemistry
In the laboratory a student finds that it takes 20.7 Joules to increase the temperature of 11.0 grams of solid platinum from 20.5 to 35.8 degrees Celsius. What is the specific heat of platinum she has measured.
Tuesday, March 11, 2014 at 11:36am

Chemistry
How do I balance the following reaction in acidic conditions? N2O4 + S8 = NO + H2SO3????
Tuesday, March 11, 2014 at 11:35am

Chemistry: Freezing point depression
What is the free sing point of a solution of ethyl alchohol, that contains 24g of the solute (C2H5OH), dissolved in 780 g of water
Tuesday, March 11, 2014 at 9:50am

chemistry
each mole of CaCO3 produces 1 mole of CaO so, convert grams CaO to moles, then back to grams of CaCO3
Tuesday, March 11, 2014 at 8:37am

chemistry
How many grams of calcium carbonate are required to prepare 50.0 grams of calcium oxide? CaCO3-> CaO + CO2
Tuesday, March 11, 2014 at 8:19am

chemistry
Titration was used to determine the molarity of acetic acid in vinegar. A primary standard solution of KHP was used to standardize the NaOH. 1. When performing this experiment, impure KHP was used to standardize the NaOH solution. If the impurity is neither acidic or basic, ...
Tuesday, March 11, 2014 at 2:25am

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