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October 21, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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Chemistry
Caprytic acid, also called octanoic acid, is an 8-carbon fatty acid that is used as a sanitizer on dairy equipment that comes in contact with milk. The acid has a molar mass of 144.21 g/mol. An aqueous solution of the sanitizer containing 12.25 g/L has a pH of 2.98. What is ...
Sunday, January 5, 2014 at 2:50pm

Grade 12 Chemistry
This is my question: AspirinTM (acetylsalicylic acid) is a monoprotic acid with molar mass of 180g/mol. An aqueous solution containing 3.3 g/L has a pH of 2.62. What percentage of acetylsalicylic acid molecules ionizes in the solution?
Sunday, January 5, 2014 at 12:40pm

chemistry Damon check my calculation
25g of a sample of ferrous sulphate was dissolved in water containing dilute h2s04 and the volume made up to one litre. 25ml of this solution required 20ml of this solution required 20ml of n/10 kmn04 solution for complete oxidation. Calculate the percentage of f2s047h20 in ...
Saturday, January 4, 2014 at 9:43pm

chemistry
a 350ml buffer solution is .150M in HF and .150M in NAF. What mass of naoh could this buffer neutralize before ph rises above 4.0? So far I got .285714 from 10^-.544. After that I tried to do .285714(x/.0525-x) but this doesn't worl. The answer is 1.2g. Help, please?
Saturday, January 4, 2014 at 4:13pm

Chemistry
A sample of NH3 gas occupies 75.0 liters at STP. How many molecules is this?
Friday, January 3, 2014 at 5:05pm

chemistry
write the british standard related to following details 1. A plain carbon steel with a composition of 0.46% of carbon and 1.5% of manganese. the steel is supplied to a harden ability specification
Friday, January 3, 2014 at 1:07am

chemistry
Calculate the uncertainty in speed of an electron if its position in space is known within the range of ±2pm. Assume me = 9×(10^-31) kg
Thursday, January 2, 2014 at 6:58am

Chemistry
What is the relationship between temperature and the equilibrium constant k? Is it a direct or indirect relationship? And why?
Wednesday, January 1, 2014 at 11:54pm

Chemistry
Equimolar amounts of gas A and B, each at an initial partial pressure of 1.00 atm are combined in a flask. The flask is sealed and allowed to react to completion according to the reaction: 2A(g)+ B(g) --> C(g) What is the final pressure inside the flask?
Wednesday, January 1, 2014 at 11:08pm

chemistry
The kinetic theory of gases is based on a number postulates from which the equation P= 1/3× N/V×m×µ² is derived (P is the pressure of the gas, N the number of molecules in the container, m the mass of each molecule and µ² is the mean ...
Wednesday, January 1, 2014 at 9:20pm

Chemistry
What is the effect of Independent Variable on Dependent Variable ?
Monday, December 30, 2013 at 6:01pm

Chemistry
What is the effect of Independent Variable on Dependent Variable ?
Monday, December 30, 2013 at 5:53pm

analytical chemistry
Regarding ICP analysis 4. For each of the following electrical discharge sources list the major strengths and limitations: a. dc arcs, b. ac arcs, c. ac sparks.
Friday, December 27, 2013 at 8:08am

chemistry
Where is an electron in 3Py orbital most likely to be found and where does the probability it vanish?
Thursday, December 26, 2013 at 9:19am

chemistry
The kinetic theory of gases is based on a number postulates from which the equation P= 1/3× N/V×m×µ² is derived (P is the pressure of the gas, N the number of molecules in the container, m the mass of each molecule and µ² is the mean ...
Thursday, December 26, 2013 at 7:55am

chemistry
copper,stone,wood&ice what property they gives?
Wednesday, December 25, 2013 at 1:05pm

chemistry
Please post any helpful links(tutorials) and practice worksheets for naming alkanes,alkenes, and alkyns.
Monday, December 23, 2013 at 2:14pm

chemistry
what current will be able to produce 20 volume of chlorine by electrolysis at STP within one hour?
Sunday, December 22, 2013 at 6:57am

Chemistry
I am struggling in naming alkanes,alkenes,... How do you determine the parent chain? I know it is the longest chain,but there are structures that look quite complicated....the branched ones are counted...!!!! I am so confused on determining the correct parent chain!!!!!! ...
Saturday, December 21, 2013 at 8:14pm

chemistry
Estimate the surface energy of (110) face of K crystals given just the information in the periodic table. Express your answer in the unit of J/cm2.
Saturday, December 21, 2013 at 10:08am

chemistry
Polyglycolic acid, PGA, is a polymer that we know rather well how to control the structure of (even though there are currently only limited applications). So in the lab we have created two types of PGA for testing, a linear chain PGA and a branched chain PGA. Assume comparable...
Saturday, December 21, 2013 at 10:08am

chemistry
Lead iodide, PbI2, has a Ksp in water of 7.1e-9 M3 at room temperature. Calculate the solubility of PbI2 in water. Express your answer in grams per liter. What is the solubility of PbI2 in 0.1 M NaI (aq)? Express your answer in grams per liter.
Saturday, December 21, 2013 at 10:05am

chemistry
A slab of plate glass containing dissolved helium is placed in a vacuum furnace at a temperature of 400 C to remove the helium from the glass. The concentration of helium is constant throughout the glass before vacuum heat treatment. After 10 minutes in vacuum at 400 C, at ...
Saturday, December 21, 2013 at 10:04am

chemistry
A pressure vessel is lined with a membrane to reduce the loss of helium. The membrane is made of a material through which the diffusivity of helium at 25 C is 3.091 x 10-10 m2/s. The concentration at the inner surface is maintained constant at 4.00 x 10-6 kg/m3. The ...
Saturday, December 21, 2013 at 10:03am

chemistry
Composition A: 5% MgO - 95% SiO2 Composition B: 20% MgO - 80% SiO2 The two glasses above are soaked in molten calcium chloride (CaCl2) at the same temperature for a time long enough for the properties of the two glasses to approach a steady value. What glass will have the ...
Saturday, December 21, 2013 at 10:02am

chemistry
On the basis of electrical measurements, it is concluded that the equilibrium vacancy concentration in a given metal is two orders of magnitude higher at 807 C than at 498 C. What is the energy of vacancy formation (ΔHv in kJ/mol) for this metal?
Saturday, December 21, 2013 at 10:01am

chemistry
Determine the amount (in grams) of boron required to be substitutionally incorporated into 1.000 kg of germanium in order to achieve a charge carrier density of 3.091 x 1017/cm3. Assume intrinsic carriers are negligible. What type of conduction will be present in this material...
Saturday, December 21, 2013 at 9:57am

chemistry
Determine if light with wavelength 3.00 x 10-7 m incident on gallium nitride (GaN) can generate electrons in the conduction band. Gallium nitride has a band gap of is 3.2 eV. Photons with wavelengths below what value will generate electrons in the conduction band of GaN? (...
Saturday, December 21, 2013 at 9:55am

chemistry
For each pair of materials, indicate which has the larger band gap. 1. GaAs BN 2. AlAs InAs 3. C Ge 4. InAs GaAs 5. InP GaP
Saturday, December 21, 2013 at 9:55am

chemistry
Draw the three dimensional structure of hydrazine (H2N-NH2) and answer the following questions about what you have drawn. How would you describe the geometric arrangement of electron domains around each nitrogen? linear trigonal planar tetrahedral trigonal bipyramidral ...
Saturday, December 21, 2013 at 9:52am

Chemistry
Determine the linear density of atoms (atoms/m) along the [111] direction of gold at 300K. What is the interplanar spacing (m) between [111] planes in gold at 300K?
Saturday, December 21, 2013 at 7:33am

chemistry
What is the minumum acceleration potential (V) that must be applied to a beam of free electrons for diffraction to occur in a crystal of niobium (Nb)? Express your answer in volts.
Saturday, December 21, 2013 at 5:46am

Solid State Chemistry
Which molecule ( KI or LiF ) has the higher boiling point? Select the single most important reason below to justify your choice should have the higher melting point Both molecules are nonpolar but the higher melting includes hydrogen bonding Both molecules are nonpolar but the...
Friday, December 20, 2013 at 3:07pm

Chemistry
Rank the following three elements in order of increasing Young'sModulus: Ge, Sn, Si. My answer is as follows: Sn<Ge<Si. I am not sure if this correct. Can someone verify. Thanks.
Friday, December 20, 2013 at 1:43pm

Chemistry
If 1.50 g of H2C2O4 2H2O were heated to drive off the water of hydration, how much anhydrous H2C2O4 would remain? Thank you! Please explain clearly.
Thursday, December 19, 2013 at 9:13pm

Chemistry
You are operating an X-ray tube with a molybdenum (Mo) target by applying an acceleration potential of 50 keV. Calculate the values of two characteristic wavelengths, λKα and λSWL. Express your answers in meters.
Thursday, December 19, 2013 at 4:29pm

chemistry
The particle wavelength of your lecturer in 3.091 on his way from the office to 10-250 (200 yards, 1 yard = 0.9144 m) has been determined to be 4.045 x 10 -36m. Taking his body weight to be 178 lbs (1 lb = 0.4536 kg), how long does it take him to get to his class? (answer in ...
Thursday, December 19, 2013 at 7:37am

chemistry
The human eye responds to a light stimulus (generates a sensation of "light") upon receiving light energy of 10eV (and more). If we take 6000 angstroms as the average wavelength, how many photons must the eye receive to register a light sensation?
Thursday, December 19, 2013 at 7:35am

chemistry
what is the percentage yield for Sr(NO3)2 + Na2SO4 -> SrSO4 + 2 NaNO3. mass of strontium nitrate is 0.788g mass of sodium sulfate is 1.258g mass of dry filter paper 0.759 g mass of dried precipitate in filter paper 1.317g
Thursday, December 19, 2013 at 1:07am

chemistry
CO2(g) + H2(g) equilibrium reaction arrow CO(g) + H2O(g) Calculate the equilibrium concentration of each compound if 2.00 moles of CO2 and 2.40 moles of H2 are placed in a 3.90 liter container at 300°C. Kc = 2.30 for the reaction at this temperature. [CO2] = M [H2] = M [CO...
Wednesday, December 18, 2013 at 9:36pm

chemistry
A competing technology uses a photovoltaic cell to charge a battery which can then be used to power a LED light. To compare these technologies, we make some reasonable assumptions. We assume the solar cell is 10 cm on a side, and that it has an efficiency of 15%. We assume the...
Wednesday, December 18, 2013 at 5:34pm

chemistry
In the TV show "Breaking Bad" the characters attempt to use HF acid to dissolve guns (among other things). Here we consider instead dissolving guns (which we will assume are pure iron) with sulfuric acid. Complete the balanced reaction for reacting iron in dilute ...
Wednesday, December 18, 2013 at 4:00pm

chemistry
In the process of electrolysis, electrical power is used to separate water into oxygen and hydrogen molecules via the reaction: H2O --> H2 + ½O2 This is very much like running a hydrogen fuel cell in reverse. We assume that only the activation potential for the ...
Wednesday, December 18, 2013 at 3:55pm

Chemistry
The mass of a sample of boron atoms is 5.60 g. How many boron atoms are in this sample? Show work, and explain.
Wednesday, December 18, 2013 at 3:51pm

chemistry
the oxidation number of Mo in Na2MoO4 is what?
Tuesday, December 17, 2013 at 11:09am

chemistry
If the ground state is 4S^2 , what is the name of the element
Tuesday, December 17, 2013 at 10:54am

chemistry
how many grams of chromium are required to react with 125 mL of 0.75M CuSO4?
Monday, December 16, 2013 at 10:05pm

Chemistry, due soon please help
calculate the mass of 100 ppm of CO2 int the atmosphere if the atmospheres mass is 5.3x10^18 kg
Monday, December 16, 2013 at 10:05pm

Chemistry
Do pipettes blow up like balloons when they are heated. Why or why not?
Monday, December 16, 2013 at 8:10pm

Chemistry
ONe day, you were walking along the road with your friend and saw a piece of solid that you've never seen before. You were curious about the identity of the substance so you tried to give it to the Department of Science. You found out from them that it is a new found ...
Monday, December 16, 2013 at 7:29am

chemistry
A sample of chlorine consists of 3×10to the power 6 of 35Cl and 2 × 10to the power 5 atoms od 37Cl . what is the average mass of an atom of chlorine in the sample?
Monday, December 16, 2013 at 2:29am

chemistry
How can you convert the number of atoms of these isotopes 35Cl and 37Cl to percentage?
Monday, December 16, 2013 at 1:03am

chemistry
What is the the energy (in Joules per photon) of visible radiation that has a wavelength of 6.405e-7 meters? The speed of light is 3.00x108 m/s and Planck's constant is 6.626x10-34 J*s.
Sunday, December 15, 2013 at 11:38pm

chemistry
30 ml of sugar syrup is mixed with water to yield a concentration of 60% sugar solution. What is the volume of the solution? The sugar has a molecular formula of c12h22o11 and a mass of 12g.
Sunday, December 15, 2013 at 8:24pm

chemistry
Nitroglycerin, C3H5N3O9, is a shock sensitive liquid (density = 1.450 g/mL) that detonates by the reaction 4 C3H5N3O9(l) ® 10H2O(g) + O2(g) + 6N2(g) + 12CO2(g) How many grams of N2 will be produced during the detonation of 2.813 L of nitroglycerin?
Sunday, December 15, 2013 at 7:06pm

CHEMISTRY.
Lowering of vapor pressure is directly proportional to: a) Temperature b) Mole fraction of Solute c) Mole fraction of Solvent d) Amount of solution
Sunday, December 15, 2013 at 5:26pm

CHEMISTRY.
Lowering of vapor pressure is directly proportional to: a) Temperature b) Mole fraction of Solute c) Mole fraction of Solvent d) Amount of solution
Sunday, December 15, 2013 at 5:26pm

CHEMISTRY.
Lowering of vapor pressure is directly proportional to: a) Temperature b) Mole fraction of Solute c) Mole fraction of Solvent d) Amount of solution
Sunday, December 15, 2013 at 4:01pm

chemistry
What is the total molar concentration of ions in 45.26 mL of 0.2068 M K2CO3 (a strong electrolyte)?
Sunday, December 15, 2013 at 3:36pm

chemistry
The mass of an individual atom of calcium is 40.08 amu. How many atoms would weigh a total of 15.46 g of this element if the mass of 1 amu is 1.6605x10-24 g?
Saturday, December 14, 2013 at 6:48pm

Chemistry
The relative humidity of air is equal to the ratio of the partial pressure of water in the air to the equilibrium vapor pressure of water at the same temperature. If the relative humidity of the air is 30.% and its temperature is 23°C, how many molecules of water are ...
Friday, December 13, 2013 at 7:58pm

chemistry
Will tea bag contains caffeine? What is the bad effects if one drink too much tea bags everyday?
Friday, December 13, 2013 at 8:05am

Chemistry
Can someone please help me answer these questions? Is additional information other than what is given needed to solve? Thanks in advance. 1) Calculate the PH of a buffer containing 0.100 M propanoic acid, HC3H5O2 and .100 M NaC3H502 after the following have been added. Ka for ...
Friday, December 13, 2013 at 1:39am

chemistry
will iron rust if it is placed in a test tube of ethanol acid with no water inside. Explain
Thursday, December 12, 2013 at 11:57pm

chemistry
ok, so i did a lab called: measurements using electrochemical cels and electroplating, and one of the post lab questions asks,if the student fails to dry the electrode, in this case (Cu+2), what effect does it have on the calculated value of Faraday? and what affect does it ...
Thursday, December 12, 2013 at 5:48pm

chemistry
how many moles of nitrogen would be needed to make 10.0 ammonia?
Thursday, December 12, 2013 at 5:41pm

college chemistry
If 100.0 mL of 0.0025 M Na2SO4 (aq)is saturated with CaSO4 how many grams of CaSO4 would be present in the solution? [Hint: Does the usual simplifying assumption hold?]
Thursday, December 12, 2013 at 5:38pm

chemistry
An excess of aqueous AgNo3 reacts with 41 mL of 5 M K2CrO4(aq) to form a precipitate. What is the precipitate?
Thursday, December 12, 2013 at 12:41pm

chemistry
how do u find the percantage composition of an element?
Wednesday, December 11, 2013 at 10:03pm

chemistry
How many CO2 molecules are formed when 10 methanol molecules react?
Wednesday, December 11, 2013 at 8:36pm

chemistry
arrange the following 0.10M solutions in order of increasing (H+). NaBr NH4Cl LiCn
Wednesday, December 11, 2013 at 8:02pm

Chemistry cp
How many moles of fertilizer are there in 55,000g of fertilizer
Wednesday, December 11, 2013 at 6:25pm

Chemistry
how can you tell if something with oxidize or reduce some other thing, based on the standard reduction potential table?
Wednesday, December 11, 2013 at 5:46pm

Chemistry
how can you tell if something with oxidize or reduce some other thing, based on the standard reduction potential table?
Wednesday, December 11, 2013 at 5:46pm

Chemistry
If a tablet of TUMS contains 500mg of the active ingredient, CaCO3, how many tablets would it take to neturalize the 1.5g of HCl? From balanced equation: CaCO3 + 2HCl = CaCl2 + H2O + CO2
Wednesday, December 11, 2013 at 3:09pm

Chemistry
60.0 mL of O2 was collected over water at a total pressure of 755 torr and a temp of 25C. The vapor pressure of water at 25C is 24 torr. How many moles of O2 were collected? Could you please explain and show the steps? I know the answer is 2.36x10^-3.
Wednesday, December 11, 2013 at 3:06pm

chemistry
the total number of atoms represented in the formula: (NH4)3 PO4 (DOT) 6H20
Wednesday, December 11, 2013 at 12:10am

Chemistry - Chemical Equilibrium
In a solution with carbon tetrachloride as the solvent, the compound VCl4 undergoes dimerization: 2VCl4 <-> V2Cl8 When 6.6834 g VCl4 is dissolved in 100.0 g of carbon tetrachloride, the freezing point is lowered by 5.97*C/ Calculate the value of the equilibrium constant ...
Tuesday, December 10, 2013 at 6:51pm

Chemistry
In a solution with carbon tetrachloride as the solvent, the compound VCl4 undergoes dimerization: 2VCl4 <-> V2Cl8 When 6.6834 g VCl4 is dissolved in 100.0 g of carbon tetrachloride, the freezing point is lowered by 5.97*C/ Calculate the value of the equilibrium constant ...
Tuesday, December 10, 2013 at 6:49pm

Chemistry
What will be the concentration of the solution formed when 5.72mL of 8.50M HCl is diluted to 250mL?
Tuesday, December 10, 2013 at 3:32pm

Chemistry
Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of SO2(g). 2SO2(g)+O2(g)=2SO3(g) Kc=1.7*10^8 [SO3]aq=0.0034 M [O2]aq=0.0018 M
Tuesday, December 10, 2013 at 12:22pm

College Chemistry
Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of SO2(g). 2SO2(g)+O2(g)=2SO3(g) Kc=1.7*10^8 [SO3]aq=0.0034 M [O2]aq=0.0018 M
Tuesday, December 10, 2013 at 4:19am

Chemistry
Methane reacts with water to form CO and H2 as follows: CH4(g)+H2O(g)=CO9g)+3H2(g) The value of Kp at 298 k for the reaction is 7.7 *10^24, calculate Kc. If you can please show the steps I would greatly appreciate it. Thank you
Tuesday, December 10, 2013 at 4:06am

chemistry
25.75 mL of a hydrochloric acid solution reacts completely with a solid sample of magnesium carbonate producing 170.8 mL of CO2 which is collected over water at 24.00°C and 731.0 torr total pressure. The vapor pressure of water at 24.00°C is 22.4 torr. 2 HCl(aq) + ...
Tuesday, December 10, 2013 at 1:31am

CHEMISTRY
I haven't learned half reactions for oxidation and reduction so please teach me by leading me from step to step.... I don't get this.. Sn2+ +2Fe3+---> Sn4+ +2Fe2+ The answer key says Oxidation: Sn2+--->Sn4+ +2e- Reduction: 2Fe3+ + 2e----->2Fe2+
Tuesday, December 10, 2013 at 12:09am

CHEMISTRY
I haven't learned half reactions for oxidation and reduction so please teach me by leading me from step to step.... I don't get this.. Sn2+ +2Fe3+---> Sn4+ +2Fe2+ The answer key says Oxidation: Sn2+--->Sn4+ +2e- Reduction: 2Fe3+ + 2e----->2Fe2+ **where did the...
Monday, December 9, 2013 at 11:09pm

Chemistry #4
What is the concentration of a solution formed by dissolving 10.0g of ammonium acetate in enough water to form 150.0mL of solution? Could someone please explain and show me how to do this? I have the answer= .865M But I am not sure exactly how?!
Monday, December 9, 2013 at 10:21pm

Chemistry(DrBob222)
So, i did this lab, a solubility and thermodynamics lab of KNO3, and in it we had to determine the delta h delta g and delta s, the question i have is what is the relationship of the signs delta h, delta s, and delta g, to the dissociation of the salt and the temperature ...
Monday, December 9, 2013 at 7:24pm

Chemistry
What is [H+], [OH-], pH, and pOH for a 0.048mol/L solution of the weak benzoic acid, C6H5COOH?
Monday, December 9, 2013 at 4:46pm

Chemistry
A sample of ca(oh)2 is allowed to stand in distilled water until a saturated solution forms. A 50.00 mL sample of this saturated solution is neutralized with 24.4 mL of 0.05 mol/L Hcl 2hcl+ ca(oh)2>cacl2+2h2o Use this information to calculate the ksp for ca(oh)2
Monday, December 9, 2013 at 4:41pm

Chemistry
Use equations to explain how a buffer system, such as hno2:no2, reacts with h3o and oh?
Monday, December 9, 2013 at 4:40pm

Chemistry
1 L of 0.002 mol/L Pb(NO3)2 has been prepared. Given that ksp for PbCl2 is 1.7 x10^-5, what is the largest number of moles of nacl that can be added to this solution without causing a precipitate to form.
Monday, December 9, 2013 at 4:39pm

chemistry
You have purifiedLDH using affinity chromatography. Using the bradford assay you determined the total protein concentration of the column fraction to be 10 mg/ml in a final volume of 2.4 ml. You diluted some of your column fraction to 1 mg/ml using SDS Page sample loading ...
Monday, December 9, 2013 at 12:46pm

Chemistry(DrBob222)
for a thermodynamics lab, I have to graph the ln K vs. 1/T, so does the ln K go on the y-axis and the 1/T go on the x-axis?
Sunday, December 8, 2013 at 10:45pm

Chemistry
How many grams of K2Cr2O7 (Potassium dichromate) must be used to make 250 ml of a0.125 M solution?
Sunday, December 8, 2013 at 8:59pm

Chemistry
How do I balance this chemical reaction? __K + __CaBr2 → __KBr + __Ca
Sunday, December 8, 2013 at 8:56pm

chemistry
Q2: A sample of carbon dioxide(CO2) has a mass of 55g and occupies 3.3L at 100C. What pressure does the gas exert (in kPa)?
Sunday, December 8, 2013 at 7:45pm

chemistry
Q3: In the combustion reaction of 149g of propane(C3H8) with excess oxygen, what volume of carbon dioxide(CO2) is produced at STP? (note: balance the reaction first) C3H8 + O2  3CO2 + H2O
Sunday, December 8, 2013 at 7:44pm

chemistry
Aluminum granules are a component of some drain cleaners because they react with sodium hydroxide to release both energy and gas bubbles to help clear the drain clog. The reaction is: 2NaOH + Al + 6H2O  2NaAl(OH)4 + 3H2 (note: balance the reaction first) What mass of ...
Sunday, December 8, 2013 at 7:43pm

AP Chemistry
for a thermodynamics lab, I have to graph the ln K vs. 1/T, so does the ln K go on the y-axis and the 1/T go on the x-axis?
Sunday, December 8, 2013 at 7:26pm

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