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July 26, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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Chemistry
Silver chromate is sparingly soluble in aqueous solutions. The Ksp of Ag2CrO4 is 1.12× 10–12. What is the solubility (in mol/L) of silver chromate in 1.4 M potassium chromate aqueous solution? In 1.4 M silver nitrate aqueous solution? In pure water?
Tuesday, November 12, 2013 at 4:11pm

Chemistry
The Ksp of CaSO4 is 4.93× 10–5. Calculate the solubility (in g/L) of CaSO4(s) in 0.300 M Na2SO4(aq) at 25 °C
Tuesday, November 12, 2013 at 3:19pm

chemistry
a 60.0 g sample of chromium at 82.0 degrees celsius was place in 80.0 g of water. Assume there is no loss of heat to the environment. What is the final temperature of the water and chromium? The initial water temperature was 24.0 degrees celsius
Tuesday, November 12, 2013 at 12:54pm

chemistry
Two new metallic elements have been discovered, Cimium (Ci) and Sadowium (Sd). Both the pure elements and their solutions form simple cubic lattices. The bond strengths of the Ci-Ci and Sd-Sd bonds are known, but not the Ci-Sd bond. Bond Bond Energy (kJ/mole) Ci-Ci -245 Sd-Sd...
Tuesday, November 12, 2013 at 11:54am

Chemistry
A saturated solution of calcium chromate (CaCrO4) freezes at -0.10 C. What is Ksp for CaCrO4? Assume complete dissociation. The density of the solution is 1.0 g/mL.
Tuesday, November 12, 2013 at 11:19am

chemistry
Draw the compound that would produce 4-ethyl-3-hexanol in the presence of a nickel catalyst and hydrogen.
Tuesday, November 12, 2013 at 9:00am

Chemistry
Measuring the conductivity of an aqueous solution in which 0.0200 mol CH3COOH has been dissolved in 1.00 L of solution shows that 2.96 % of acetic acid molecules have ionized to CH3COO- ions and H3O+ ions. Calculate the equilibrium constant for ionization of acetic acid and ...
Tuesday, November 12, 2013 at 7:07am

Chemistry
Define minimum assay
Tuesday, November 12, 2013 at 4:08am

chemistry
What is the final volume of NaOH solution prepared from 250.0mL of 0.800M NaOH if you wanted the final concentration to be 0.200M
Tuesday, November 12, 2013 at 1:09am

Chemistry
Assume that the normal blood buffer contains 0.00080 M carbonic acid and 0.0085 M hydrogen carbonate, the pKa = 6.35 for carbonic acid and the volume of blood in the body is 7.00 L. The blood pH, due to disruption is now 7.20. What is the ratio of [HCO3−]/[H2CO3] now ...
Monday, November 11, 2013 at 11:05pm

Chemistry
If the wavelength if determined to be 0.018 nm, at what velocity is the electron traveling? (The mass of an electron is 9.11x10^-31kg) I know the answer is 4.0x10^7 m/s, but i cannot figure how they got this. Could someone please explain it to me and show me? Thanks!!
Monday, November 11, 2013 at 10:59pm

Chemistry
If you need to prepare 250.0 mL of a pH 5.00 buffer that has a total buffer concentration of acetic acid + sodium acetate of 0.050M, how many moles of each will you need to prepare the solution? Given solutions of acetic acid and sodium acetate with concentrations of 0.10M and...
Monday, November 11, 2013 at 10:11pm

chemistry will somebody please help!!
What is the Kc for the following reaction at equilibrium at 800∘C if [CO2]= 0.030M ? CaCO3(s)⇌CaO(s)+CO2(g)
Monday, November 11, 2013 at 9:38pm

General Chemistry : for Nursing
Im Having a really Hard time with this problem :( ---> A sample containing 5.60g O2 gas has a volume of 31.0L . Pressure and temperature remain constant. 1 .) Oxygen is released until the volume is 8.00L . How many moles of O2 are removed?
Monday, November 11, 2013 at 9:36pm

chemistry
Phosphorus pentachloride, PCl5, reacts with water to form phosphoric acid, H3PO4, and hydrochloric acid, HCl. PCl5(s) + 4H2O() → H3PO4(aq) + 5HCl(aq) (a) What mass of PCl5 is needed to react with an excess quantity of H2O to produce 23.5 g of H3PO4? (b) How many ...
Monday, November 11, 2013 at 8:49pm

Chemistry
Dr Bob!! Need your help!!
Monday, November 11, 2013 at 8:29pm

chemistry
same question as before What is the Kc for the following reaction at equilibrium at 800∘C if [CO2]= 0.030M ? CaCO3(s)⇌CaO(s)+CO2(g)
Monday, November 11, 2013 at 8:21pm

Chemistry
Hi, I'm a little stuck on this problem: Find the pH of the Hydrochloric acid solution when 5.0 mL of concentrated HCl, with a specific gravity of 1.18 and has 37% (w/w) purity is diluted to 2.0L
Monday, November 11, 2013 at 8:08pm

chemistry
What mass of NiSO4 is present in 2.00 x 102ml of 6.00% NiSO4(aq)? (The density of the solution is 1.13g/ml.)
Monday, November 11, 2013 at 6:51pm

CHEMISTRY
Please explain the answer. Which statement about this reaction is correct? 2Fe(s)+3CO2(g)--->Fe2O3(s)+3CO(g) delta H = 26.6 kJ A. 26.6 kJ of energy are released for every mole of Fe reacted B. 26.6 kJ of energy are absorbed for every mole of Fe reacted C. 53.2 kJ of energy ...
Monday, November 11, 2013 at 6:40pm

CHEMISTRY
Please explain. The enthalpy changes for two different hydrogenation reactions of C2H2 are: C2H2+H2---->C2H4 Delta H 1 C2H2+2H2---->C2H6 Delta H 2 Which expression represents the enthalpy change for the reaction below? C2H4+H2---->C2H6 Delta H = ? A. Delta H 1 + Delta...
Monday, November 11, 2013 at 6:39pm

CHEMISTRY
Please explain. The average bond enthalpy for the C-H bond is 412 kJ mol^-1. Which process has an enthalpy change closest to this value ? A. CH 4 (g)---> C(s)+2H2(g) B. CH 4(g)--> C(g)+2H2(g) C. CH 4(g)---> C(s)+ 4H(g) D. CH 4 (g)---> CH3(g)+ H(g)
Monday, November 11, 2013 at 6:34pm

Quantitative Chemistry
Ignoring activities, determine the molar solubility (S) of Zn(CN)2 in a solution with a pH = 4.36. Ksp (Zn(CN)2) = 3.0 × 10-16; Ka (HCN) = 6.2 × 10-10.
Monday, November 11, 2013 at 5:38pm

Chemistry
Please explain. The average bond enthalpy for the C-H bond is 412 kJ mol^-1. Which process has an enthalpy change closest to this value ? A. CH 4 (g)---> C(s)+2H2(g) B. CH 4(g)--> C(g)+2H2(g) C. CH 4(g)---> C(s)+ 4H(g) D. CH 4 (g)---> CH3(g)+ H(g)
Monday, November 11, 2013 at 5:36pm

Chemistry
Please explain. The enthalpy changes for two different hydrogenation reactions of C2H2 are: C2H2+H2---->C2H4 Delta H 1 C2H2+2H2---->C2H6 Delta H 2 Which expression represents the enthalpy change for the reaction below? C2H4+H2---->C2H6 Delta H = ? A. Delta H 1 + ...
Monday, November 11, 2013 at 5:29pm

chemistry
What is the Kc for the following reaction at equilibrium at 800∘C if [CO2]= 0.030M ? CaCO3(s)⇌CaO(s)+CO2(g)
Monday, November 11, 2013 at 5:21pm

Chemistry
Please explain the answer. 1. Which statement about this reaction is correct? 2Fe(s)+3CO2(g)--->Fe2O3(s)+3CO(g) delta H = 26.6 kJ A. 26.6 kJ of energy are released for every mole of Fe reacted B. 26.6 kJ of energy are absorbed for every mole of Fe reacted C. 53.2 kJ of ...
Monday, November 11, 2013 at 5:20pm

Chemistry
Assuming complete dissociation, what is the pH of a 3.73 mg/L Ba(OH)2 solution?
Monday, November 11, 2013 at 3:54pm

Chemistry
After 53.0 min, 14.0% of a compound has decomposed. What is the half-life of this reaction assuming first-order kinetics?
Monday, November 11, 2013 at 3:41pm

AP Chemistry
How do you determine the heat of solution for a substance? how can we report this answer in both kJ/g and kJ/mol? thank you!!!
Monday, November 11, 2013 at 2:23pm

chemistry
Complete and balance the precipitation reactions. Include physical states in your equations. Ba(NO3)2(aq) + CuSO4 (aq)---> K3PO4(aq)+MgCl2 (aq)---->
Monday, November 11, 2013 at 1:35pm

chemistry
What volume of carbon monoxide gas (at STP) is needed when 1.31 moles of oxygen gas react completely in the following equation? 2 CO + O2 --> 2 CO2
Sunday, November 10, 2013 at 6:57pm

chemistry
What mass of ammonia is produced when 1.48 L of nitrogen (at STP) react completely in the following equation? N2 + 3H2 --> 2NH3
Sunday, November 10, 2013 at 6:56pm

Chemistry
A sample of unknown metal has a mass of 36.7 g. This metal was placed in boiling water at 96.0oC until the metal had reached the temperature of the water. The metal was then placed in a foam cup with 50.0 g of water in it at 20.0oC. The cup absorbs 42.0 J/oC, and the ...
Sunday, November 10, 2013 at 6:55pm

chemistry
A 0.411 mol sample of PCl5(g) is injected into an empty 4.65 L reaction vessel held at 250 °C. Calculate the concentrations of PCl5(g) and PCl3(g) at equilibrium.kc=1.80 at 250c
Sunday, November 10, 2013 at 6:28pm

chemistry
What is the the energy (in kJ/mol) of infrared radiation that has a frequency of 3.809e+13 Hz? The speed of light is 3.00x108 m/s and Planck's constant is 6.626x10-34 J*s. So i know the equation we use is E= hc/wavelength but i keep getting the wrong answer. And also, how ...
Sunday, November 10, 2013 at 4:48pm

Chemistry
Heisenberg's uncertainty principle can be expressed mathematically as Δx*Δp = h/4π, where Δx and Δp denote the uncertainty in position and momentum respectively and h is Planck's constant. What would be the uncertaintry in the position of a ...
Sunday, November 10, 2013 at 4:48pm

Chemistry
What is the mass of a fly in grams if its de Broglie wavelength is 1.545e-31 m when it is traveling at a velocity of 3.605 m/s
Sunday, November 10, 2013 at 4:47pm

Chemistry
Hydrogen exhibits several series of line spectra in different spectral regions. For example the Lyman series (nf = 1 in Balmer-Rydberg equation) occurs in the ultraviolet region while the Balmer (nf = 2) series occurs in the visible range and the Paschen (nf = 3), Brackett (...
Sunday, November 10, 2013 at 4:46pm

Chemistry
Hydrogen exhibits several series of line spectra in different spectral regions. For example the Lyman series (nf = 1 in Balmer-Rydberg equation) occurs in the ultraviolet region while the Balmer (nf = 2) series occurs in the visible range and the Paschen (nf = 3), Brackett (...
Sunday, November 10, 2013 at 4:46pm

Chemistry
For the reaction Zn(OH)2(s)+4CN-(aq)->Zn(CN)4 2-(aq)+2OH-(aq) find [CN-] when 8.5 g of Zn(OH)2 are dissolved in 1.00 L of solution.
Sunday, November 10, 2013 at 4:13pm

Chemistry
When excess NaOH is added to Zn(OH)2, the complex ion Zn(OH)4 2- is formed. Determine the molar solubility of Zn(OH)2 in .10 M NaOH. Compare with the molar solubility of Zn(OH)2 in pure water. I thought I knew how to do this problem, but I'm not getting the right answer. ...
Sunday, November 10, 2013 at 3:47pm

chemistry
Heisenberg's uncertainty principle can be expressed mathematically as Δx*Δp = h/4π, where Δx and Δp denote the uncertainty in position and momentum respectively and h is Planck's constant. What would be the uncertaintry in the position of a fly...
Sunday, November 10, 2013 at 3:43pm

chemistry
Heisenberg's uncertainty principle can be expressed mathematically as Δx*Δp = h/4π, where Δx and Δp denote the uncertainty in position and momentum respectively and h is Planck's constant. What would be the uncertaintry in the position of a fly...
Sunday, November 10, 2013 at 3:42pm

chemistry
Hydrogen exhibits several series of line spectra in different spectral regions. For example the Lyman series (nf = 1 in Balmer-Rydberg equation) occurs in the ultraviolet region while the Balmer (nf = 2) series occurs in the visible range and the Paschen (nf = 3), Brackett (nf...
Sunday, November 10, 2013 at 3:39pm

chemistry
What is the mass of a small car in grams if its de Broglie wavelength is 4.198e-38 m when it is traveling at a velocity of 11.84 m/s ?
Sunday, November 10, 2013 at 3:38pm

chemistry
Calculate the partial pressure of propane in a mixture that contains equal numbers of moles of propane (C3H8) and butane (C4H10) at 20 °C and 616 mmHg. (R=0.082 L-atm/K mol)
Sunday, November 10, 2013 at 1:14pm

chemistry
Calculate the partial pressure of propane in a mixture that contains equal numbers of moles of propane (C3H8) and butane (C4H10) at 20 °C and 616 mmHg. (R=0.082 L-atm/K mol)
Sunday, November 10, 2013 at 12:45pm

chemistry
Calculate the partial pressure of propane in a mixture that contains equal numbers of moles of propane (C3H8) and butane (C4H10) at 20 °C and 616 mmHg. (R=0.082 L-atm/K mol)
Sunday, November 10, 2013 at 12:45pm

Chemistry
A compound containing only boron, nitrogen, and hydrogen was found to be 40.3% B, 5202% N, 7.5% H by mass. If 3.301g of this compound is dissolved in 50.00g of benzene, the solution produced freezes at 1.30 degree celsius. if the freezing point depression constant/cryoscopic ...
Sunday, November 10, 2013 at 12:28am

chemistry
Determine the energy of a photon with a wavelength of 6.74 ✕ 102 nm.
Saturday, November 9, 2013 at 8:53pm

Chemistry
How much water would be formed if 2.4 grams of hydrogen reacted with 19.3 grams of oxygen?
Saturday, November 9, 2013 at 7:55pm

Chemistry
Use standards entropies and heats of formation to calculate delta Gf at 25C for a. cadmium (II) chloride (s) b. methyl alcohol, CH3OH (l) c. copper (I) sulfide (s) I really have no idea where to start with this problem. I have no idea how to calculate delta Gf, and everything ...
Saturday, November 9, 2013 at 7:41pm

Chemistry
Complete and balance the precipitation reactions. Include physical states in your equations. Ba(NO3)2(aq) + CuSO4 (aq)---> K3PO4(aq)+MgCl2 (aq)---->
Saturday, November 9, 2013 at 5:59pm

Chemistry
A 0.110-L sample of an unknown HNO3 solution required 52.1 mL of 0.150 M Ba(OH)2 for complete neutralization. What was the concentration of the HNO3 solution?
Saturday, November 9, 2013 at 3:03pm

chemistry
For the following chemical reaction write the net ionic equation, including the phases. 2HBr (aq) +Ba(OH)2(aq) --> 2H2O(l) +BaBr2 (aq)
Saturday, November 9, 2013 at 1:38pm

chemistry
A solution prepared by mixing 47.1 mL of 0.4 M AgNO3 and 47.1 mL of 0.4 M TlNO3 was titrated with 0.8 M NaBr in a cell containing a silver indicator electrode and a reference electrode of constant potential 0.175 V. The reference electrode is attached to the positive terminal ...
Saturday, November 9, 2013 at 5:45am

Chemistry
I need help I can't seem to get the right answer. Please help! 1/2 H_2 (g) + 1/2 Cl_2 (g) --> HCl (g) -92.3 kJ/mol Na(s) + 1/2 O_2(g) + 1/2H_2(g) --> NaOH(s) -426.8 kJ/mol NaCl(s) --> Na(s) + 1/2Cl_2(g) 411.1 kJ/mol H_2O(l) -->H_2(g) + 1/2O_2(g) 285.8 kJ/mol ...
Friday, November 8, 2013 at 9:22pm

chemistry
Answer the question(s) below about the following reaction. 2H2O2 (l) → 2H2O(g) + O2(g) If 50.0 grams hydrogen peroxide produce 15.0 g oxygen, what is the percent yield for this reaction?
Friday, November 8, 2013 at 5:54pm

chemistry
For the reaction below at a certain temperature, it is found that the equilibrium concentrations in a 4.87-L rigid container are [H2] = 0.0496 M [F2] = 0.0116 M [HF] = 0.429 M. H2(g) + F2(g) <==> 2 HF(g) If 0.185 mol of F2 is added to this equilibrium mixture, calculate ...
Friday, November 8, 2013 at 5:39pm

Chemistry
Among the following, which element has the lowest ionization energy? A. Na B. Cl C. Cs D. I
Friday, November 8, 2013 at 2:36pm

chemistry
MASS (GRAMS) Nac1- 0.9992 C12H22O11- 0.9822 NH4C1- 0.9510 C6H5OH- 0.9723 C9H20- 1.0038 *Find the Molar Mass (g/mol) for each * *Find the Moles of each element for each * *Find the Atoms of each element for each * - if possible show work and or equation set up to find answers
Friday, November 8, 2013 at 1:42pm

chemistry
if I mix 44 mL of sugar in 236 mL of water. how would I find out how many ions of sugar there were?
Friday, November 8, 2013 at 11:04am

chemistry
In hydrated copper sulfate, the chemical formula is CuSO4.5H2O, while that of hydrated cobalt(II) chloride is CoCl2.6H2O. I want to ask how to determine the number of moles of water is needed to hydrate any salt. Is there a pattern or formula?
Friday, November 8, 2013 at 9:55am

chemistry
How to perform an experiment to distinguish between zinc(II) hydroxide and magnesium hydroxide?
Friday, November 8, 2013 at 9:51am

Chemistry
HOw does the quantum mechanical orbital differ from a bohr orvit for an electron in a hydrogen atom?
Friday, November 8, 2013 at 9:48am

Chemistry
Why did rutherford model of the atom require that electrons be in motion whereas Thomson's model did not.
Friday, November 8, 2013 at 9:47am

Chemistry Check
Just want to make sure that my thought process is right on this one. 5 compounds: n-butyl chloride n-butyl bromide sec-butyl chloride tert-butyl chloride and crotyl chloride Each is reacted with NaI (SN2?) and AgNO3 (SN1?) And we have to rank the reaction time and wether we ...
Friday, November 8, 2013 at 2:28am

Chemistry
Okay, the question my teacher asked for one of our pre-labs went as followed: For each reaction, select one compound that reacts rapidly and give a structural equation for the process. Silver nitrate in ethanol I'm confused on how to do this. Also From my basic ...
Friday, November 8, 2013 at 12:49am

Chemistry
What would happen if too much refrigerent was present in the system(refrigerator)? Too little? HELP!!! I'm doing a C^3 assignment for chem and its due tomorrow can someone help me please!
Thursday, November 7, 2013 at 10:50pm

Chemistry
What would happen if too much refrigerent was present in the system(refrigerator)? Too little? HELP!!! I'm doing a C^3 assignment for chem and its due tomorrow can someone help me please!
Thursday, November 7, 2013 at 10:26pm

Chemistry
What would happen if too much refrigerent was present in the system(refrigerator)? Too little? HELP!!! I'm doing a C^3 assignment for chem and its due tomorrow can someone help me please!
Thursday, November 7, 2013 at 10:24pm

Chemistry
I know that this is an off topic question, but I need you to respond to this.... I received barely an A in my chemistry class, and my teacher gave me a 2/25 on an assignment... Although I got that grade, I still have an A.. I asked my teacher why and she said that it is not ...
Thursday, November 7, 2013 at 9:01pm

Chemistry
I know that this is an off topic question, but I need you to respond to this.... I received barely an A in my chemistry class, and my teacher gave me a 2/25 on an assignment... Although I got that grade, I still have an A.. I asked my teacher why and she said that it is not ...
Thursday, November 7, 2013 at 8:43pm

Chemistry AP
Each response gives a pair of solutions. Which pair of solutions should conduct electrical current equally well? 1. 0.10 M NH3 and 0.10 M NH4Cl 2. 0.10 M NaNO3 and 0.10 M HNO2 3. 0.10 M HBr and 0.10 M HF 4. 0.10 M NaCl and 0.10 M NaClO4 Please help... I would also would like ...
Thursday, November 7, 2013 at 7:49pm

chemistry
I am still having trouble with this question It says What is the molarity of a solution containing 18.0g of KCl in 262mL of KCl solution? When I calculated it I got .92154 m. I had changed 18 g into moles and 262 ml into liters and then divided the moles into liters. I was ...
Thursday, November 7, 2013 at 5:57pm

Chemistry (Dr.Bob222)
The half-life of P-32 is 14 days. How long after a sample is delivered can a laboratory wait to use a sample in an experiment if they need at least 10 percent of the original radioactivity? I need help on how to set up this problem. What is the general equation to use for a ...
Thursday, November 7, 2013 at 5:41pm

chemistry
given 10.8 grams of substance y,if the substance absorbs 231 kilojoules of energy and the specfic heat of substance is 6.55 J/g*0C what is the heat change
Thursday, November 7, 2013 at 5:29pm

Chemistry
i need some chemical properties of the element arsenic.i have looked online and havent found any i have also looked in my book.
Thursday, November 7, 2013 at 5:05pm

chemistry
HI(aq)+KOH(aq)→H2O(l)+KI(aq) express this as a complete ionic equation
Thursday, November 7, 2013 at 4:25pm

Chemistry
An activationenergy of 2.0 eV is required to form a vacancy in a metal. At 800°C there is one vacancy for every 104 atoms. At what temperature will there be one vacancy for every 1000 atoms?
Thursday, November 7, 2013 at 3:28pm

chemistry
hich proton gave rise to the peak that appears at 9.31 ppm on the 1H NMR?
Thursday, November 7, 2013 at 2:01pm

chemistry
HELPPPP!!!! A mixture is prepared using equal masses of the two volatile liquids benzene, C6H6, and ethanol, C2H5OH. What is the mole fraction of benzene in this mixture?
Thursday, November 7, 2013 at 4:27am

chemistry
You dissolved 450.0 g of sugar (C12H22O11) in 150 mL of water. The density of water is 1.00 g/mL a. calculate the molarity of the solution b. calculate the molality of the solution
Thursday, November 7, 2013 at 3:39am

chemistry
8.90 g of NH4Cl is added to 19.7 g of water. Calculate the molality of the solution
Thursday, November 7, 2013 at 12:23am

chemistry
1) What is the chemical formula for the compound formed between thallium(iii) and bromine? 2) What is the chemical formula for the compound formed between thallium(iii) and sulfur? HINT!: each compound wil be neutral. What is the charge of the thallium(iii) ion? What is the ...
Thursday, November 7, 2013 at 12:22am

Chemistry Please :/
When a metal was exposed to light at a frequency of 4.26× 1015 s–1, electrons were emitted with a kinetic energy of 4.50× 10–19 J. What is the maximum number of electrons that could be ejected from this metal by a burst of light (at some other frequency) ...
Thursday, November 7, 2013 at 12:21am

chemistry
A solution of iron(III) thiocyanate was produced by dissolving 7.98 milligrams solid iron(III) thiocyanate in enough water to produce a 100.00 mL solution. What is the concentration, in molarity, of the solution?
Wednesday, November 6, 2013 at 11:33pm

Chemistry #13
When a metal was exposed to light at a frequency of 4.26× 1015 s–1, electrons were emitted with a kinetic energy of 4.50× 10–19 J. What is the maximum number of electrons that could be ejected from this metal by a burst of light (at some other frequency) ...
Wednesday, November 6, 2013 at 11:01pm

chemistry
Solid sodium azide (NaN3) is used in air bags to fill them quickly upon impact. The solid NaN3 undergoes a decomposition reaction to produce Na(s) and N2(g). a. Provide the balanced equation for the decomposition of NaN3. b. What mass, in grams, of NaN3 is needed to fill the ...
Wednesday, November 6, 2013 at 10:53pm

chemistry
A sample of carbon dioxide has a volume of 22.0 L at 5.80 x 102 mm Hg. What pressure, in torr, would be needed to increase the volume to 48.6 L at constant temperature?
Wednesday, November 6, 2013 at 10:53pm

ap chemistry
Under certain conditions, the reaction 3A + 2B -> 4C was observed to proceed at a rate of 0.00348 M· s−1. What was the corresponding rate of change in reactant A?
Wednesday, November 6, 2013 at 8:40pm

General Chemistry I
At noon on a clear day, sunlight reaches the earth's surface at Madison, Wisconsin, with an average power of approximately 4.00 kJ·s–1·m–2. If the sunlight consists of photons with an average wavelength of 510.0 nm, how many photons strike a 6.60 ...
Wednesday, November 6, 2013 at 8:31pm

chemistry
What is the molarity of a solution containing 18.0g of KCl in 262mL of KCl solution?
Wednesday, November 6, 2013 at 8:06pm

AP Chemistry
At 298K and 1 atm, a 0.5 mol sample of O2 and a seperate 0.75 mol sample of CO2 gas have the same: A. mass B. density C. average molecular speed D. average molecular kinetic energy E. number of atoms Please explain, and thanks for helping!
Wednesday, November 6, 2013 at 6:29pm

AP Chemistry
Equal masses of Ne and Ar are placed in a rigid, sealed container. If the total pressure in the container is 1.2 atm, what is the partial pressure of Ar?
Wednesday, November 6, 2013 at 6:27pm

Chemistry AS
CALCULTE
Wednesday, November 6, 2013 at 2:39pm

Chemistry LAB 2
Calculate the Molar Enthalpy of Neutralization in kJ/mol of the reaction between a monoprotic acid and a monoprotic base, given the following information: *Make sure you report your answer using the correct sign* The temperature change equals 9.80 degrees C, 50.0mL of 1.00 M ...
Wednesday, November 6, 2013 at 12:05pm

Chemistry LAB 1
What is the Molar Enthalpy of Neutralization in kJ/mol if 5.00 moles of HCl(aq) (acid) neutralized 5.00 moles of NaOH(aq) (base) and released 6649J of heat? *Make sure you report your answer using the correct sign* DrBob222 gave me some help and I worked it out and got 1329.8 ...
Wednesday, November 6, 2013 at 12:02pm

chemistry volume problem
Can someone please explain to me how to do this?! I am completely lost. Calculate the volume indicated for each of the following: liters of a 2.00M KCl solution to obtain 0.600mol of KCl.
Wednesday, November 6, 2013 at 9:41am

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