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September 3, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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chemistry
You have 333 mL of alkaline solution at pH = 11.1. You wish to neutralize this by reacting it with 222 mL of acid. What must be the value of the pH of the acid?
Friday, May 31, 2013 at 1:36am

Chemistry
What is the volume of a sample of helium that has a mass of 5.13x10^-3 and a density of 0.17847g/L
Friday, May 31, 2013 at 12:05am

chemistry
try comparing the e values with of silver and i think you will see a reason why..
Thursday, May 30, 2013 at 11:36pm

chemistry
Silver will spontaneously reduce which of the following? Reaction E (volts) Na+ + e- ---> Na -2.71 Co2+ + 2e- ---> Co -0.28 Ag+ + e- ---> Ag .80 A) Na B) Co2+ C) Na+ D)Co E) None of these
Thursday, May 30, 2013 at 10:31pm

chemistry
Describe what happens in a fission reaction. What is a commonly used isotope in a nuclear fission reactor? Describe how a fission nuclear reactor power plant works.
Thursday, May 30, 2013 at 8:46pm

chemistry
Describe the subatomic structure of the nucleus, including the structure of each nucleon. Draw a picture. Describe the forces that hold the nucleus together and draw them on your diagram. Explain how beta emission works.
Thursday, May 30, 2013 at 8:45pm

chemistry
2.The data in the table show the amount of a 500 g sample of sodium-24 over time. Make a graph of the data (remember to label all axes and title the graph). What is the half-life of sodium-24? Explain how you determined your answer. Sodium-24 decays by beta emission. Write a ...
Thursday, May 30, 2013 at 8:44pm

CHEMISTRY
The following data were obtained when a Ca2+ ion selective electrode was immersed in a series of standard solutions. Ca2+ (M) 3.38E-5 3.38E-3 3.38E-1 E(mV) -74.8 -18.7 37.7 Calculate the concentration of a sample that gave a reading of -22.5 mV
Thursday, May 30, 2013 at 7:59pm

CHEMISTRY
Chromium plating is done using a dichromate solution. How long would it take to plate 1.0x10-2mm thick onto a car bumper with surface area 0.25m^2 in a 25.0 Amp electrolytic cell? (density of chromium is 7.19g/cm^3)
Thursday, May 30, 2013 at 7:46pm

Chemistry
A comparison of density values obtained by X-ray diffraction reveals that the percentages of vacant sites in aluminum (Al) are 0.0700% at 923 K and 0.0090% at 757 K. Given this data, determine the number of vacant sites per cm3 at 550 K. Express your answer as vacancies/cm3.
Thursday, May 30, 2013 at 6:59pm

Chemistry
A comparison of density values obtained by X-ray diffraction reveals that the percentages of vacant sites in aluminum (Al) are 0.0700% at 923 K and 0.0090% at 757 K. Given this data, determine the number of vacant sites per cm3 at 550 K. Express your answer as vacancies/cm3.
Thursday, May 30, 2013 at 6:58pm

chemistry
The N-N bond energy is difficult to measure. Given the values of 190 kJ/mol for the N-Cl bond energy and 240 kJ/mol for the Cl-Cl bond energy, determine the maximum de Broglie wavelength of an electron capable of breaking the N-N bond. Express your answer in m.
Thursday, May 30, 2013 at 6:37pm

chemistry
What should be the pH of the aqueous layer to extract caffeine? There are three aqueous solutions that you may choose from. Answer A. pH >14, using 2.5 M NaOH (aq) B. pH 1, using 0.1 M HCl (aq) C. pH 6.2, using 0.1 M NaHCO3 (aq)
Thursday, May 30, 2013 at 6:04pm

CHEMISTRY
Suppose you are studying coordination compounds of Co(II) with the ligand pyridine (py, C5H5N, molar mass=79.10). You isolate a crystalline compound, and because the only available anions are Cl- and NO3-, you hypothesize that the empirical formula of the coordination compound...
Thursday, May 30, 2013 at 5:52pm

Chemistry
Calcium oxide can be prepared by heating calcium metal in oxygen according to the reaction: 2Ca+ O(2) --> 2CaO. How many grams of calcium would be needed to produce 15.0 grams of calcium oxide?
Thursday, May 30, 2013 at 5:52pm

chemistry
how do i convert 0.00183338433 g/mL to mM? and putting it in 4 significant numbers. thank u
Thursday, May 30, 2013 at 12:15pm

chemistry
What should be the pH of the aqueous layer to extract caffeine? There are three aqueous solutions that you may choose from. Answer A. pH >14, using 2.5 M NaOH (aq) B. pH 1, using 0.1 M HCl (aq) C. pH 6.2, using 0.1 M NaHCO3 (aq)
Thursday, May 30, 2013 at 9:41am

organic chemistry
for each of the following compounds, draw the form in which it will predominate at ph=3, ph=6, ph=10, and ph=14. a)CH3COOH b)CH3CH2NH3 c) CF3CH2OH please explain how to get answers. my book does not give clear examples.
Thursday, May 30, 2013 at 8:26am

chemistry
Derive the empirical formula of a hydrocarbon that on analysis gave the following percentage by mass composition: C = 85.63 % and H = 14.37 %. If the molecular mass of this compound is 56 g, derive the molecular formula.
Thursday, May 30, 2013 at 2:07am

CHEMISTRY SCIENCE
Points in favour: 1.Diffusion helps reduce the pollution of toxic gases. Points against: 1. old stains of ink, tea/coffee, cooked food are hard to remove through diffusion, or just hard to remove ... can u please elaborate on the same topics we are supposed to write it for one...
Thursday, May 30, 2013 at 1:17am

chemistry
A gaseous mixture containing 6 moles of oxygen, 8 moles of helium and 6 moles of carbon dioxide in a container under a pressure of 40 atm. Calculate the partial pressure of th3 individual gases.?
Thursday, May 30, 2013 at 12:22am

Chemistry Honors
Hydrogen burns to give water. If 200cm3 of H2 reacts with 150cm3 of O2 what volume of water vapor is produced
Wednesday, May 29, 2013 at 11:39pm

Chemistry
BaSO4(s)__><--- Ba2+(aq) + SO42−(aq) Adding what substance produces more SO4^2-??? This was a question, that had options of 1. SO4^2- 2. Ba2+ 3. BaSO4(s) 4. and i think a compound with NH in it Thank you
Wednesday, May 29, 2013 at 11:03pm

Chemistry
calculate the density of an aluminum pipe if the mass of the aluminum is 37g and the level of the water ina graduated cylinder increased by 11.0 mL when the pipe is submerged in the graduated cylinder. then calculate the percent error of the experimental value if the reference...
Wednesday, May 29, 2013 at 10:09pm

Chemistry
What is the ionic form of the equation H2O + Br2 + SO2 --> HBr + H2SO4 ?
Wednesday, May 29, 2013 at 9:58pm

Chemistry
A solution of household bleach contains 5.25% sodium hypochlorite, NaOCl, by mass. Assuming that the density of bleach is the same as water, calculate the volume of household bleach that should be diluted with water to make 500.0 mL of a pH = 10.10 solution.
Wednesday, May 29, 2013 at 8:18pm

Chemistry
calculate the volume of the 3.0 M stock solution needed to make a diluted 30mM solution in 400ml
Wednesday, May 29, 2013 at 5:41pm

Chemistry
I am doing a lab on Creating An Effective Airbag. We need to find out how much of the base is needed, which is NaHCO3,if we have 2.25 M of HCl, which is the acid. How much of the sample do we need? and how do we find out how much we need?
Wednesday, May 29, 2013 at 5:23pm

Chemistry
calculate the volume of the 3.0 M stock solution needed to make a diluted 30mM solution in 400ml
Wednesday, May 29, 2013 at 5:01pm

chemistry
i have to write lab report based on my determination of chemical formula & in lab we did experiment & found out the formula was cucl2*2h2o, in my lab report i have to start with mole to mole ratio how can i start writing that?
Wednesday, May 29, 2013 at 9:59am

CHEMISTRY
1 In the group of the alkali metals the degree of hydration-------- down the group. decreases increases is constant has no fixed pattern 2 Which of these statements is not true? liquid ammonia is is used to form carbides All metals react with carbon to form carbides lithium ...
Wednesday, May 29, 2013 at 7:26am

CHEMISTRY! DR.BOB PLEASE HELP
Tungsten trioxide (WO3) has a rich yellow color and is often used as a pigment in ceramics and paints. In order to test a ceramic vase for its WO3 content, a 10.19 g sample of the vase was ground and reduced with Pb(Hg) to convert any WO3 to W3 . The resulting W3 was ...
Wednesday, May 29, 2013 at 2:09am

Chemistry DrBob222
5. What volume would 27g of neon at 2 atm pressure and 50°C occupy? I have solved the problem correctly, but I am not sure if I have the correct units on this conversion so that everything will cancel out. Also, is it right to have 20g Ne/1mole K? I seem to be missing ...
Wednesday, May 29, 2013 at 1:11am

chemistry
calculate the molarity of 29.25 grams of NaCl in 2.0 liters of solution
Tuesday, May 28, 2013 at 11:36pm

chemistry
Tungsten trioxide (WO3) has a rich yellow color and is often used as a pigment in ceramics and paints. In order to test a ceramic vase for its WO3 content, a 10.19 g sample of the vase was ground and reduced with Pb(Hg) to convert any WO3 to W3 . The resulting W3 was ...
Tuesday, May 28, 2013 at 10:36pm

Chemistry
What is the mole fraction and mass percent of NaCl when the molality is 1.71m?
Tuesday, May 28, 2013 at 6:37pm

Chemistry
Let's say that you are asked to design an airbag for a car. You know that the bag should be filled with gas with a pressure higher than atmospheric pressure, say 828 mmHg at a temperature of 22.0 C . THe bag has a volume of 45.51. What quantity of sodium azide should be ...
Tuesday, May 28, 2013 at 5:47pm

Chemistry
What is HO HO C6 H6 CH2 CH NH2?
Tuesday, May 28, 2013 at 4:26pm

Chemistry
Please help me out! Gas law homework! How many liters of HCl (g) at STP can be produced from 5.44 g of Cl2 and excess H2 according to the following equation? H2 (g) + Cl2 (g) --> 2 HCl (g) Thank you so much in advance.
Tuesday, May 28, 2013 at 3:59pm

chemistry
To save on production costs, most automobile bumpers are never coated with more than 200 g of chromium. Determine how much time a standard bumper should be immersed in a chromium vat. need full explanation i did find this question but it was not explained the calculations and...
Tuesday, May 28, 2013 at 3:49pm

chemistry
Making the simplistic assumption that the dissolved NaCl(s) does not affect the volume of the solvent water, determine the constants m and b in the equation Molarity = m⋅density + b that relates the NaCl molarity to the NaCl(aq) density. Take the density of water to be 1...
Tuesday, May 28, 2013 at 2:49pm

Chemistry
How many mL of 0.976 M sodium hydroxide, NaOH, are necessary to completely neutralize 46 mL of sulfuric acid, H2SO4?
Tuesday, May 28, 2013 at 12:19pm

Chemistry
concentration of hydrogen ion is 3.8*10^-3M.what is its pH?
Tuesday, May 28, 2013 at 9:41am

Chemistry
If a gas at 1.2 atm of pressure and 22.0 degrees of Celsius occupies 0.350L, what pressure will hold the same sample of gas in a volume of 0.050L if the temperature of the gas increases 25 degrees of Celsius?
Tuesday, May 28, 2013 at 5:45am

Chemistry
If a gas at 1.2 atm of pressure and 22.0 degrees of Celsius occupies 0.350L, what pressure will hold the same sample of gas in a volume of 0.050L if the temperature of the gas increases 25 degrees of Celsius?
Tuesday, May 28, 2013 at 5:45am

Chemistry
At some temperature, Keq = 33 for the reaction H2 + I2 „³ 2HI. If initially, [H2] = .0600 M and [I2] = .0300 M, what are all three equilibrium concentrations?
Tuesday, May 28, 2013 at 12:42am

chemistry
Two liquids A and B on mixing form an ideal solution. The vapour pressure of the solution containing 2 moles of A and 4 moles of B is 0.2 atm. If the vapour pressure of pure A at a certain temperature is 0.3 atm then what will be the vapour pressure of pure B at that temperature?
Tuesday, May 28, 2013 at 12:16am

chemistry
18.5g Al is submerged in 20.2g of water with a total temperature of 27°C. How much energy in joules is absorbed by the Al if the temperature changes to 32°C ?
Tuesday, May 28, 2013 at 12:04am

chemistry
Suppose that 2.00 moles of HCl in a 1.00L glass flask slowly decomposes into H2 and Cl2. When equilibrim is reached, the concentrations of H2 and Cl2 are both 0.214M. What is the Keq?
Tuesday, May 28, 2013 at 12:03am

Chemistry
If 1.62 mold of CS2 burns with 5.65 mol of O2, how many moles of the excess reactant will still be present when the reaction is over? the chemical equation is CS2+3O2=2SO2+CO2
Monday, May 27, 2013 at 11:58pm

Chemistry
What mass of N2O5 will result from the reaction of 6.0 mol of NO2 if there is a 61.2% yield in the reaction?
Monday, May 27, 2013 at 11:54pm

chemistry
the concentration of urea in a solution prepared by dissolving 16g of urea in 39 g of H2O is ________% by mass. The molar mass of urea is 60.0 g/mol
Monday, May 27, 2013 at 10:57pm

Chemistry
Cyclohexane has a freezing point of 6.6 degree Celsius and a K(f) of 20.0 degree Celsius/m. 1.50g of an unknown solute is dissolved wth 18.0g of cyclohexane. The freezing point of the solution was 1.3 degree Celsius Using this iInformation assuming the solute doesn't ...
Monday, May 27, 2013 at 9:08pm

Chemistry
Assume you are starting with a 10x solution. how would you make it a 7.5x dilution?
Monday, May 27, 2013 at 3:06pm

Chemistry--DrBob222
Estimate the number of moles of gas (and mass of gas assuming that it is all N2) inside your family car (or a friends if you don't have one). If the amount of gas was compressed at constant temperature to fit inside a coke can what ould the pressure inside the coke can be...
Monday, May 27, 2013 at 2:58pm

Chemistry
What is the volume of HCl stock (37%) you must add in order to make up a 10.0% diluted HCl solution, if the final volume to be achieved is 600mL?
Monday, May 27, 2013 at 2:01pm

chemistry
diffusion helps detecting leakages in cylinders or gas stoves
Monday, May 27, 2013 at 2:43am

Chemistry
So I did a lab that consist of baking cookies and the mass of the final products isn't equal to the ingredients used. Could there be mass lost as gas ? What other factors might there be? Thanks
Sunday, May 26, 2013 at 11:52pm

chemistry
As of May 17th 1213, the price of cobalt metal on the London Metal Exchange was $27500 per metric ton. One metric ton is defined as 1000Kg. Determine the price of cobalt in cents per atom.
Sunday, May 26, 2013 at 11:25pm

Chemistry
Nitric acid is commonly purchased as a 16 M solution, which has a density of 1.41 g/mL. Convert this molarity to a) mass percentage, b) molality, c) mole fraction. A) 16molHNO3(63.02HNO3/1MolHNO3)=1,008.32gH​NO3 - 1,000gH20(1MolH20/1.41ml/g)=1410ml/mol w/w= 1008.32/1410...
Sunday, May 26, 2013 at 10:30pm

chemistry
Hi, I was hoping someone could double check a chemistry answer for me. I am trying to calculate the Ksp of Ag2CrO4. This question is based on a experiment to determine ksp experimentally. In the experiment the Ksp of silver chromate was calculated using a single displacement ...
Sunday, May 26, 2013 at 6:06pm

Quantum Chemistry
Assume that the double-slit experiment could be carried out with electrons using a slit spacing of b= 10.0 . To be able to observe diffraction, we choose lamda=b , and because diffraction requires reasonably monochromatic radiation, we choose (delta P)/P= 0.0100. Part A What ...
Sunday, May 26, 2013 at 6:03pm

science chemistry
Given 4K + O2 → 2K2O, what is the reaction type? Single Replacement Double Replacement Synthesis (formation) Decomposition
Sunday, May 26, 2013 at 5:51pm

chemistry
what volume of water is required to make 0.20 M solution from 16 ml of 0.5 M solution?
Sunday, May 26, 2013 at 6:21am

chemistry
How much hydrogen gas (mL) would be rpoduced at 25 degreez C and 1.34 atm if 5.5 grams of zinc reacts with 25mL of 0.05 M hydgrchloric acid? Please respond with how u found the answer
Saturday, May 25, 2013 at 8:24pm

chemistry
how much heat would be required to warm the earth's oceans by 1 degree celcius if the volume of the earths oceans is 137x100000000km3 and the density of the seawater is 1.03g/cm3
Saturday, May 25, 2013 at 6:44pm

Chemistry
what is the molarity of 28.9 g of cacl2 dissolved in water to make 0.78 l of solution
Saturday, May 25, 2013 at 3:03pm

Chemistry
If 10g of NO react with 20g of O2, what is the maximum amount of NO2 that can be produced? My answer is Mol NO = 10/30 = 0.333 mols Mol O2 = 20/32 = 0.625 mols To react all the O2 you would need 2 NO*0.625 moles of NO/1mole O2 =1.25 O2? but, we just have 0.333 mols, so NO is ...
Saturday, May 25, 2013 at 2:08pm

Chemistry
If 1.20g of steam at 100.0 celcius condenses into 38.5 g of water, initially at 27 celcius what is final temperature of water
Saturday, May 25, 2013 at 12:23pm

Chemistry
A solution contains 40.0 g of sodium chloride and 200.0 g of water. Calculate the NaCl concentration as a a) mass percentage, b) molality, c) mole fraction. I have trouble finding mole fraction. I believe I've got the other two, but I'm not 100% sure.
Friday, May 24, 2013 at 11:07pm

Chemistry
Calculate the osmotic pressure at 22 °C of a 0.25 M solution of a) dextrose, b) magnesium chloride.
Friday, May 24, 2013 at 10:44pm

Chemistry
Describe the subatomic structure of the nucleus, including the structure of each nucleon. Draw a picture. Describe the forces that hold the nucleus together and draw them on your diagram. Explain how beta emission works.
Friday, May 24, 2013 at 6:22pm

Chemistry
Compare and contrast the processes of nuclear fission and fusion, showing similarities and differences. Describe which, if any, of these processes is naturally occurring. If so, where?
Friday, May 24, 2013 at 6:16pm

Chemistry
Estimate the number of moles of gas (and mass of gas assuming that it is all N2) inside your family car (or a friends if you don't have one). If the amount of gas was compressed at constant temperature to fit inside a coke can what would the pressure inside the coke can be...
Friday, May 24, 2013 at 3:47pm

Chemistry
How many grams would you need to weigh out in order to have 2.7 x 1021 formula units of LiCl? i am so confused :(
Friday, May 24, 2013 at 2:49pm

Chemistry
Calculate the volume occupied by 200g of steam at 200 °C and 0.5 atm. is my answer correct: PV = nRT V = nRT/P V = gRT/mm P V = (200g H2O)(0.0821 liters atm/1mole K)(473 K)/ (18g H2O/1mole )(0.5 liters atm) = 863 liters
Friday, May 24, 2013 at 2:17pm

Chemistry -- DrBob222
A gas initially at STP is heated to 50°C keeping the volume constant. What is its new pressure? I used this formula: P1 = 1 atm T1 = 273 K T2 = 323 K solve for P2 P2 = P1 (T2/T1) But, where do I use the 50 degrees C? Also, is my answer correct: P2 = 1atm x 323K/273K = 1.18...
Friday, May 24, 2013 at 12:30pm

Chemistry
A .25 g chunk of sodium metal is cautiously dropped into a mixture of 50g of water and 50 g of ice both at 0 C 2Na(s) + 2h2o(l) -> 2naoh(aq) + H2 Delta H = -368 kj Will the ice melt ..
Friday, May 24, 2013 at 8:16am

chemistry
Oxygen vapor combines with hydrogen gas to produce liquid water. If 50.0 g of oxygen combines with 105 L of Hydrogen gas (at STP) how many grams of water could be produced?
Thursday, May 23, 2013 at 11:12pm

Chemistry
How many liters of oxygen are required to react completely with 5.9 L c3H8?
Thursday, May 23, 2013 at 11:10pm

Chemistry
Determine the mass of 100mL of vinegar if the density of vinegar is 1.09 g/mol
Thursday, May 23, 2013 at 8:20pm

chemistry
What is the balanced equation for a reaction of iron with chlorine?
Thursday, May 23, 2013 at 7:22pm

chemistry
What volume (in liters) of 0.94 M KOH solution should be added to a 0.090 L solution containing 9.1 g of glutamic acid hydrochloride (Glu, FW=183.59; pka1=2.23, pka2=4.42, pka3=9.95) to get to pH 10.20?
Thursday, May 23, 2013 at 6:55pm

chemistry
Ignoring activities, determine the molar solubility (S) of Zn(CN)2 in a solution with a pH = 3.63. Ksp (Zn(CN)2) = 3.0 × 10-16; Ka (HCN) = 6.2 × 10-10. I'm completely lost help please!
Thursday, May 23, 2013 at 5:18pm

Chemistry
Would the VSEPR notation of CH3Cl be AX4?
Thursday, May 23, 2013 at 1:49pm

chemistry
in fcc crystal system with unit cell of an edge 200pm calculate its density if 200grams of this element contains 24*10E23
Thursday, May 23, 2013 at 1:48pm

Chemistry
40.0 g of magnesium chloride (MgCl2) in 250.0 g of water at 22 °C.Calculate a) the vapor pressure of this solution, b) the freezing point, c) the boiling point. I know it is something like this, but I continue to get the incorrect answer. A) 40.og Mgcl2*(1mol mgcl2/ 95.2 ...
Thursday, May 23, 2013 at 1:03pm

chemistry project please help really need it
help me out in choosing a topic for my project it should be anyhow related to chemistry help me please
Thursday, May 23, 2013 at 6:27am

Chemistry
What happens if you add more solute to a saturated solution?
Wednesday, May 22, 2013 at 10:45pm

chemistry
If you add a metal piece to excess acid, what of listed factors below will increase, decrease, or have no impact on how fast a reaction happens? a) lower molarity (concentration) of a solution b) higher molarity (concentration)of a solution c) increase volume of a solution (...
Wednesday, May 22, 2013 at 10:08pm

Chemistry
If 10g of NO react with 20g of O2, what is the maximum amount of NO2 that can be produced? How do I know exactly which is limiting and which is excess, is there a calculation that shows this?
Wednesday, May 22, 2013 at 9:46pm

Chemistry
What is the intermolecular force for BaCO3?
Wednesday, May 22, 2013 at 9:09pm

Chemistry
The volume of a gas sample is 200 L at 740 torr. What is its volume at 760 torr?
Wednesday, May 22, 2013 at 7:42pm

Chemistry
What is the mass of a sample of acetylene gas (C2H2)that contains 4.44 x 1034 atoms of carbon? Also, Im not sure how to convert from moles of C to moles of C2H2.
Wednesday, May 22, 2013 at 7:40pm

Chemistry
The volume of a gas sample is 200 L at 740 torr. What is its volume at 760 torr?
Wednesday, May 22, 2013 at 7:35pm

chemistry
(a)how much energy in KJ/mol is released when an electron makes a transition from n=5 to n=2 in a hydrogen atom?
Wednesday, May 22, 2013 at 7:20pm

chemistry
sodium vapor lamps, used for public lighting, emit 489nm yellow light. what energy is emitted by: (a) an excited sodium atom when it generates a photon? (b) 1 mol of excited sodium atoms at this wavelength?
Wednesday, May 22, 2013 at 7:17pm

Chemistry
Write a procedure to demonstrate the effect of higher concentrations of HCl on its rate of reaction with antacid tablets. I have HCl with a concentration of 1.0 mol/L. This is what I have so far. Are my concentrations correct for this procedure? E is my control and, a,b,c,d ...
Wednesday, May 22, 2013 at 6:40pm

Chemistry
What is the normality of a solution which contains 4.03-g of sodium carbonate in 300.-mL of solution?
Wednesday, May 22, 2013 at 6:06pm

Chemistry
what volume of oxygen is needed to react with solid sulfur to form 6.20 L of sulfur dioxide according to the reaction S(s) + O2(g) yield SO2(g)
Wednesday, May 22, 2013 at 2:35pm

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