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November 23, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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Chemistry
How do i provide ionic equations , for example to this one --> HNO3(aq) + KOH(aq)
Tuesday, May 6, 2014 at 10:03pm

Chemistry
Calculate the volume of 2.00 M solution of KOH that is required to neutralize 30.0 mL of 1.00 M solution of HNO3.
Tuesday, May 6, 2014 at 9:36pm

Chemistry
What is the % mass/volume of a 3.00 M solution of NaCl?
Tuesday, May 6, 2014 at 9:35pm

chemistry
For each organic compound, determine if it is an alkane, alkene, or alkyne. (No ringed structures and only one multiple bond per structure.) 1. C10H18 - alkyne 2. C15H32 - alkane 3. C20H40 - alkyne 4. C5H10 - alkene 5. C3H6 - alkene 6. C7H16 - alkane I am not sure on number 3
Tuesday, May 6, 2014 at 9:12pm

CHEMISTRY HELP !!!!
Assuming the following reaction proceeds in the forward direction, 3 Sn4+(aq) + 2 Cr(s)  3 Sn2+(aq) + 2 Cr3+(aq) a. Sn4+(aq) is the reducing agent and Cr(s) is the oxidizing agent. b. Cr(s) is the reducing agent and Sn2+(aq) is the oxidizing agent. c. Sn4+(aq) is the ...
Tuesday, May 6, 2014 at 8:56pm

CHEMISTRY HELP !!!!
Which of the following statements is/are CORRECT? 1. Naturally occurring isotopes account for only a small fraction of known radioactive isotopes. 2. A few radioactive isotopes with long half-lives, such as U-235 and U-238, are found in nature. 3. Trace quantities of some ...
Tuesday, May 6, 2014 at 8:53pm

Chemistry
Calculate the molarity of an HCI solution, if 20.0 mL of it were neutralized by 10.0 mL of 2.00 M solution of NaOH.
Tuesday, May 6, 2014 at 8:32pm

Chemistry
Calculate the volume of 2.00 M solution of KOH that is required to neutralize 30.0 mL of 1.00 M solution of HNO3.
Tuesday, May 6, 2014 at 8:29pm

Chemistry
What is the % mass/volume of a 3.00 M solution of NaCl?
Tuesday, May 6, 2014 at 8:21pm

chemistry
A silver block, initially at 59.4∘C^\circ C, is submerged into 100.0 g{\rm g} of water at 25.3∘C^\circ C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 27.6∘C^\circ C.
Tuesday, May 6, 2014 at 8:02pm

chemistry
Calculate the molar it of a solution that contains 5.4 get of sodium sulfate dissolved in enough water to make 3.5 L of solution
Tuesday, May 6, 2014 at 5:44pm

Chemistry
The formation constant of [M(CN)6]4– is 2.50 × 1017, where M is a generic metal. A 0.170-mole quantity of M(NO3)2 is added to a liter of 1.31 M NaCN solution. What is the concentration of M2 ions at equilibrium?
Tuesday, May 6, 2014 at 4:19pm

Chemistry
A tank contains helium for filling balloons. It holds 6.75 L of Ne at 24.8 atm and 27.5 °C. What would be the volume of this helium at 2.13 atm and 10.6 °C?
Tuesday, May 6, 2014 at 3:14pm

chemistry
The mean activity coefficients of HBrin 5.0 and 20.0 mmol kg –1 are 0.930 and 0.879, respectively. Consider a hydrogen electrode in HBr(aq) solution at 25 °C operating at 1.15 atm. Calculate the change in the electrode potential when the molality of the acid solution ...
Tuesday, May 6, 2014 at 2:21pm

(5) Chemistry - Science (Dr. Bob222)
Consider a buffer made from 0.13 M sodium acetate and 0.10 M acetic acid in 1L. What amount of KOH must be added to cause an increase of the pH by 0.14? A) 0.048 mol B) 0.038 mol C) 0.028 mol D) 0.018 mol E) 0.008 mol
Tuesday, May 6, 2014 at 2:03pm

Chemistry - Science (Dr. Bob222)
Ammonia is a weak base with a Kb of 1.8 x 10-5. A 100.0 mL sample of 0.13 M aqueous solution of ammonia (NH3) is mixed with 87 mL of 0.15 M solution of the strong acid HCl, calculate the pH of the final solution. A) 2.9 B) 11.1 C) 8.8 D) 5.2 E) None of the above
Tuesday, May 6, 2014 at 1:11pm

Chemistry - Science (Dr. Bob222)
How many mmol ( millimoles) of HCl must be added to 130.0 mL of a 0.40M solution of methyl amine (pKb = 3.36) to give a buffer having a pH of 11.59? Thank you for your help!
Tuesday, May 6, 2014 at 12:57pm

CHEMISTRY HELP !!!!
What is the name of the compound having the formula [Cr(en)2(H2O)2]SO4? a. dihydroxydiethlyenediamminechromate(2) sulfate b. diaquabis(ethylenediamine)sulfatochromat​e(4) c. bis(ethylenediamine)diaquachromium(2) sulfato d. diaquabis(ethylenediamine)sulfatochromiu​...
Tuesday, May 6, 2014 at 11:16am

chemistry
If you have a 29.6 mass percent KCl in benzene,what is the new boiling point?
Tuesday, May 6, 2014 at 11:05am

chemistry
If you collect hydrogen gas over water at a temperature of 85*C, what is the volume of just the water if the pressure of hydrogen is 1.23 atm and the grams of hydrogen was 2.6
Tuesday, May 6, 2014 at 11:01am

chemistry
What is the [CH3NH3+] of a solution which is 0.1003 M in CH3NH2 and 0.1204 M in CsOH? CH3NH2(aq) + H2O(l) « CH3NH3+(aq) + OH−(aq)
Tuesday, May 6, 2014 at 10:37am

chemistry
What is the [C7H5O2−] in a solution which is 0.1283 M in HC7H5O2 and 0.1364 M in HBr? HC7H5O2(aq) + H2O(l) « C7H5O2−(aq) + H3O+(aq) Ka = 6.5000e-5
Tuesday, May 6, 2014 at 10:37am

chemistry
What would Qc be if the volume of the container decreased by a factor of 1.774 for the following reaction? PH3(g) + BCl3(g) → PH3BCl3(s) KC = 534.8 at 353.0oC
Tuesday, May 6, 2014 at 10:36am

chemistry
At 2273 K the equilibrium constant for the reaction 2 NO(g) « N2(g) + O2(g) KC = 2400 What would be the equilibrium concentration of N2 if the initial concentration of NO was 0.1778 M?
Tuesday, May 6, 2014 at 10:36am

chemistry
At 674.5 K the equilibrium concentrations of N2, H2, and NH3 were 0.1614 M, 0.1128 M, and 0.005892 M, respectively. What is the equilibrium constant for the reaction below? 2 NH3(g) → N2(g) + 3 H2(g)
Tuesday, May 6, 2014 at 10:35am

chemistry
How much heat energy is needed to change the temperature of 25.00 mL of water from 5.0°C to 75.0°C? The molar heat capacity of water for this process Cp = 75.38 J/(mol °C), d = 1.00 g/mL.
Tuesday, May 6, 2014 at 8:44am

chemistry
A sample of oxygen gas is collected by displacement of water at 25°C and 1.17 atm total pressure. If the vapor pressure of water is 23.756 mm Hg at 25°C, what is the partial pressure of the oxygen gas in the sample?
Monday, May 5, 2014 at 11:25pm

Chemistry
A mixture consists of 0.52g of X, 0.77g of Y,and 1.11 g o fZ. What is the mass % of Z in the mixture?
Monday, May 5, 2014 at 10:59pm

Chemistry
Consider the following reaction at constant P. Use the information here to determine the value of ΔSsurr at 398 K. Predict whether or not this reaction will be spontaneous at this temperature. 4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g); ΔH = -1267 kJ A)ΔSsurr...
Monday, May 5, 2014 at 10:21pm

Chemistry
Zn+HCl---->ZnCl2+H2 If you measure the total volume of collected gas over water at 65*C to be 728 mL at a total pressure of 845 torr, how many milliliters of 2.6 HCl would be required to produce the correct amount of hydrogen?
Monday, May 5, 2014 at 9:57pm

Chemistry
Zn+HCl---->ZnCl2+H2 If you measure the total volume of collected gas over water at 65*C to be 728 mL at a total pressure of 845 torr, how many milliliters of 2.6 HCl would be required to produce the correct amount of hydrogen?
Monday, May 5, 2014 at 9:56pm

Chemistry
The fluoride ion concentration in a saturated solution of magnesium fluoride, MgF2, is 2.3 10-3 M. Calculate the value for the equilibrium constant.
Monday, May 5, 2014 at 9:20pm

Chemistry
Aniline, C6H5NH2, is a weak base. If the hydroxide ion concentration of a 0.201 M solution is 9.2 10-6 M, what is the ionization constant for the base?
Monday, May 5, 2014 at 9:19pm

Chemistry - Science (Dr. Bob222)
Posted by Ana on Saturday, May 3, 2014 at 11:23am. A zinc-copper battery is constructed as follows (standard reduction potentials given below): Zn | Zn2+ (0.10 M) || Cu2+ (2.50 M) | Cu Zn2+ + 2 e- → Zn(s) Eº = -0.76 V Cu2+ + 2 e- → Cu(s) Eº = 0.34 V The ...
Monday, May 5, 2014 at 9:19pm

chemistry
An 0.727 mol sample of argon gas at a temperature of 22.0 °C is found to occupy a volume of 26.2 liters. The pressure of this gas sample is how many mm Hg?
Monday, May 5, 2014 at 8:04pm

Chemistry
The heat of solution of ammonium chloride is 15.2 kJ/mol. If a 6.187 g sample of NH4Cl is added to 65.0 mL of water in a calorimeter at 26.5°C, what is the minimum temperature reached by the solution? [specific heat of water = 4.18 J/g°C; heat capacity of the ...
Monday, May 5, 2014 at 7:24pm

chemistry: please check work
How many grams of solute are contained in 64.3 mL of 0.0238M KOH? Do I convert 64.3ml to L=.0643L Multiiply .0643L and .0238M KOH=.00153 Multiply .00153 and 56.105 g/mol KOH=.0858g KOH
Monday, May 5, 2014 at 6:28pm

Chemistry
Describe electron delocalization.
Monday, May 5, 2014 at 6:10pm

chemistry
The cell shown above is a concentration cell. Both cells contain a copper solution and have copper electrodes. The only driving force for this cell is the difference in the concentration of the copper solutions. The system will react to equalize the concentration of the ions ...
Monday, May 5, 2014 at 5:49pm

Chemistry
A 271-g sample of nickel at 94.1°C is placed in 100.0 mL of water (density = 1.00 g/mL) at 23.9°C. What is the final temperature of the water? [Assume that no heat is lost to or gained from the surroundings. Specific heat capacity of nickel = 0.444 J/(g·K) and ...
Monday, May 5, 2014 at 5:41pm

Chemistry
Given the thermochemical equation 2SO2 + O2 → 2SO3, ΔH°rxn = -198 kJ/mol, what is the standard enthalpy change for the decomposition of one mole of SO3?
Monday, May 5, 2014 at 5:39pm

Chemistry
A truck has 5.9L diesel engine in it. 5.9L of the overall displacement in 6 cylinders each 102mm bore (diameter) and 120mm stroke (length). Engine operates at 16.3:1 compression ratio and with 6psi (0.41atm) of boost cruising at 1600rpm. 1.) The air mixture has an average ...
Monday, May 5, 2014 at 5:08pm

Chemistry
Given 2Al(s) + 3/2O2(g) → Al2O3(s), ΔH°f = -1,670 kJ/mol for Al2O3 (s). Determine ΔH° for the reaction 2Al2O3(s) → 4Al(s) + 3O2(g).
Monday, May 5, 2014 at 5:08pm

Chemistry
For ionic compound properties, what is the solubiity in hexane
Monday, May 5, 2014 at 5:02pm

Chemistry
What is the solubility in hexane for in an ionic compound and what is a solubility in hexane for a covalent (molecular) compound
Monday, May 5, 2014 at 4:50pm

Chemistry
Which of the following are ionic or covalent? 1. lauric acid 2. magnesium sulfate 3. phenyl salicylate 4. ammonium chloride 5. sodium chloride
Monday, May 5, 2014 at 4:48pm

Chemistry
A piece of copper metal is initially at 100.0°C. It is dropped into a coffee cup calorimeter containing 50.0 g of water at a temperature of 20.0°C. After stirring, the final temperature of both copper and water is 25.0°C. Assuming no heat losses, and that the ...
Monday, May 5, 2014 at 4:47pm

Chemistry
A system initially has an internal energy U of 493 J. It undergoes a process during which it releases 107 J of heat energy to the surroundings, and does work of 225 J. What is the final energy of the system, in J?
Monday, May 5, 2014 at 4:28pm

Chemistry
Calculate the enthalpy change for the reactions NO(g) + O(g) → NO2(g) from the following data: NO(g) + O3(g) → NO2(g) + O2(g) ΔH = -198.9 kJ O3(g) → 1.5O2(g) ΔH = -142.3 kJ O2(g) → 2O(g) ΔH = 495.0 kJ Put the answer in kJ.
Monday, May 5, 2014 at 4:06pm

chemistry
How many grams of copper will be deposited at the cathode of an electrolytic cell if a current of 680.0 mA is run through a 2.5 M solution of copper sulfate for 20.0 minutes?
Monday, May 5, 2014 at 3:15pm

chemistry
Some of the substance commonly used in stomach antiacid are MGO,MG(OH)2,AL(OH)3. Which of these substance will neutralize thr greatest amount of 0.10M HCl per gram?
Monday, May 5, 2014 at 1:19pm

chemistry
Concentrated phosphoric acid,H3PO4 was added slowly into some water to produce 5.0dm^3 of a dilute acid solution.100g of the pure phosphoric acid,H3PO4 was present in the solution.Find the concentration of the acid,in g dm^-3.
Monday, May 5, 2014 at 1:10pm

chemistry
Calculate the volume of 2.0 mol dm^-3 sulphuric acid,H2SO4 needed to prepare 2.5 dm^3 of 0.5 mol dm^-3 of the same acid solution.
Monday, May 5, 2014 at 12:53pm

Chemistry
Write the equilibrium constant expression for each of the following reactions: A. 4NO(g)+2O^2 <--> 2N^2O^4(g) B. 2NO(g)+ Br^2(g) <--> 2NOBr(g) C. CO(g)+ 2H^2(g) <--> CH^3OH(g) D. SO^2(g) + NO^2(g) <--> SO^3(g) + NO(g)
Monday, May 5, 2014 at 10:43am

chemistry
How many grams of sodium hydroxide (NaOH) are needed to prepare 250 mL of a 0.20 M (mol/dm3) sodium hydroxide solution?
Monday, May 5, 2014 at 10:35am

chemistry
7.5 g of acetic acid (CH3COOH) are diluted to 150 mL with water. What is the molarity (mol/dm3) of the acetic acid?
Monday, May 5, 2014 at 10:35am

chemistry
What is the molarity (mol/dm3) of a solution prepared by dilution of 0.125 moles of sodium chloride (NaCl) to 2.50x102 mL with water?
Monday, May 5, 2014 at 10:34am

chemistry
7.5 g of acetic acid (CH3COOH) are diluted to 150 mL with water. What is the molarity (mol/dm3) of the acetic acid?
Monday, May 5, 2014 at 10:30am

chemistry
What is the molarity (mol/dm3) of a solution prepared by dilution of 0.125 moles of sodium chloride (NaCl) to 2.50x102 mL with water?
Monday, May 5, 2014 at 10:28am

Chemistry
Consider a fuel cell that uses the reaction of ethanol with oxygen to produce electricity, CH3CH20H(l)+ 3O2(g)---> 2CO2(g)+3H2O Use thermodynamic data to determine the value of E°cell for this cell at 25 °C. I don't really know where to start. I got the standard...
Monday, May 5, 2014 at 3:39am

Chemistry
A 495-mL sample of unknown HCl solution reacts completely with Na2CO3 to form 18.1g CO2. What was the concentration of the HCl solution?
Monday, May 5, 2014 at 12:32am

Chemistry
What volume of 1.25M HCl in liters is needed to react completely (with nothing left over) with 0.750L of 0.300M Na2CO3?
Monday, May 5, 2014 at 12:31am

chemistry
Pasta packages often have different direction for cooking at high altitudes. a.) According to the directions, should you boil the pasta for a longer to shorter time? Why? b.) If the pasta water boils rapidly over medium-high heat, is there any reason to turn the heat up all ...
Sunday, May 4, 2014 at 11:28pm

Chemistry
Balance the following equation for a half reaction that occurs in basic solution. Use e– as the symbol for an electron. SO3^2- ---> S2O4^2-
Sunday, May 4, 2014 at 11:26pm

chemistry
We calculated that 30.0 grams of ice initially at -10.0 Celsius and it requires 23.1 kj of energy to bring it all the way to a boil. How much additional energy does it take to convert all of the water to steam at 100 degree Celsius? How does this compare to what we calculated ...
Sunday, May 4, 2014 at 11:26pm

Chemistry
In a particular redox reaction, MnO2 is oxidized to MnO4– and Cu2 is reduced to Cu . Complete and balance the equation for this reaction in acidic solution. Phases are optional. MnO2 + Cu^2+ ---> MnO4^- + Cu^+
Sunday, May 4, 2014 at 11:25pm

chemistry
Can CoBr2+ NH4Br + NH4OH ---> Co^2+ (aq) + 2NH3 (l) + H^+ (aq) + H2O (l) + 3Br^- form the complex [Co(NH3)5Br]Br2 if so please explain
Sunday, May 4, 2014 at 10:52pm

CHEMISTRY
The enthalpy of solution of nitrous oxide (N2O) in water is -12 kJ/mol and its solubility at 20 oC and 1.00 atm is 0.121 g per 100. g of water. Calculate the molal solubility of nitrous oxide in water at 1.600 atm and 20 oC. Hint, first find Henry's law constant at 20 oC ...
Sunday, May 4, 2014 at 9:43pm

Chemistry
If you dissolve 13.5 g of malic acid, C4H6O5, in half a liter of water (0.500 L), what is the molarity of the acid in the solution?
Sunday, May 4, 2014 at 9:39pm

Chemistry
Calculate the cell potential for the following reaction as written at 25.00 °C, given that [Zn2 ] = 0.842 M and [Ni2 ] = 0.0100 M. Standard reduction potentials can be found here. reaction: Zn(s)+Ni^2+(aq)--->Zn^2+(aq)+Ni(s) standard reduction Zn: -.76 standard ...
Sunday, May 4, 2014 at 8:27pm

chemistry
1. A 2.00 g sample of a particular compound was dissolved in 15.0 g of carbon tetrachloride. The boiling point of this solution was determined to be 77.85ºC. For pure CCl4, TB = 76.50ºC and KB = 5.03°C·kg/mol Calculate the boiling point elevation, ΔTB...
Sunday, May 4, 2014 at 7:41pm

chemistry
A 2.00 g sample of a particular compound was dissolved in 15.0 g of carbon tetrachloride. The boiling point of this solution was determined to be 77.85ºC. For pure CCl4, TB = 76.50ºC and KB = 5.03°C·kg/mol Calculate the boiling point elevation, ΔTB, ...
Sunday, May 4, 2014 at 7:38pm

chemistry
The acid dissociation constant, Ka, for this reaction is given by the following formula (this is also in your book): Ka=[H3O+][A−][HA] The acid concentration, [HA] is given in the introductory information of this problem. Using this information and your answers from the ...
Sunday, May 4, 2014 at 7:35pm

Chemistry
Using a table of standard reduction potentials, determine the best answer to the following questions. a) Which of the following reagents would oxidize Cr to Cr3 , but not Ag to Ag ? Choices: Ca^2+, Br2, Co^2+, Ca, Br^-, or Co. b) Which of the following reagents would oxidize I...
Sunday, May 4, 2014 at 7:35pm

chemistry
The chemical reaction for dissociation of an acid is: HA + H2O → H3O+ + A- Assuming all of the hydronium ion (calculated in in the previous problem) comes from this reaction, what is the concentration of conjugate base, [A-], in this system?
Sunday, May 4, 2014 at 7:34pm

chemistry
The pH of a 0.00100 M solution of a particular acid is 4.95 at 25°C. Use the solution pH to calculate the concentration of hydronium ion present [H3O+]
Sunday, May 4, 2014 at 7:33pm

chemistry
the mass of a certain mixture of BaO and CaO is found to be exactly one half that of the mixed sulfates formed from it by the action of H2SO4. calculate the percentage of BaO and CaO in the mixture.
Sunday, May 4, 2014 at 7:23pm

chemistry
Calculate the theoretical volume of gas you would expect to be evolved from your experiment if X moles of magnesium were reacted with an excess of HCl at standard conditions (STP).
Sunday, May 4, 2014 at 5:56pm

chemistry
A balloon of methane gas, CH4, has a temperature of -2 degrees celcius and contains 2.35g of the gas. What is the temperature in kelvin and how many moles of gas does the balloon contain?
Sunday, May 4, 2014 at 4:42pm

Chemistry
Long question but its my last one for homework and im stuck on this word problem. Biomass is represented by the empirical formula C60H87O23N12P. Write a balance equation for the oxidation of C60H87O23N12P with O2 to form CO2, H2O, HNO3, and H3PO4 beginning with 1000g of ...
Sunday, May 4, 2014 at 4:14pm

Chemistry
H2 (g) + I2 (g) 2 HI (g) If the initial concentrations of H2 and I2 are 1.0 M and the initial concentration of HI is 0.5 M (Kc = 54.3 at 430oC). (a) Is the reaction at equilibrium? (b) If not, which way will the reaction proceed?
Sunday, May 4, 2014 at 12:20pm

chemistry
What is the pH of a solution if [H+] = 2.3 x 10–5 M?
Sunday, May 4, 2014 at 11:54am

Chemistry
Ethanol (C2H5OH) melts at -114 degrees Celsius. The enthalpy of fusion is 5.02 kj/mol. The specific heats of solid and liquid ethanol are 0.97 J/g-K, respectively. How much heat (kJ) is needed to convert 25.0 g of solid ethanol at -135 degrees Celsius to liquid ethanol at -50 ...
Sunday, May 4, 2014 at 1:59am

CHEMISTRY
The enthalpy of solution of nitrous oxide (N2O) in water is -12 kJ/mol and its solubility at 20 oC and 1.00 atm is 0.121 g per 100. g of water. Calculate the molal solubility of nitrous oxide in water at 1.600 atm and 20 oC. Hint, first find Henry's law constant at 20 oC ...
Sunday, May 4, 2014 at 12:12am

chemistry
From the reaction below, calculate the free energy of formation for CH4(g) at 25°C, if ΔGfo(C8H8(g)) is 214.417 kJ/mol. 8CH4(g) ↔ C8H8(g) + 12H2(g) ΔGo = 620.735 kJ/mol I don't understand what equation to use. I thought it was dGfo-dGo but that doesn&#...
Saturday, May 3, 2014 at 11:04pm

Chemistry
The heat released from the combustion of 0.05 g of white phosphorus increases the temperature if 150g of water from 25 C to 31.5 C. Calculate the enthalpy change for the reaction.
Saturday, May 3, 2014 at 10:00pm

chemistry
The enthalpy of solution of nitrous oxide (N2O) in water is -12 kJ/mol and its solubility at 20 oC and 1.00 atm is 0.121 g per 100. g of water. Calculate the molal solubility of nitrous oxide in water at 1.600 atm and 20 oC. Hint, first find Henry's law constant at 20 oC ...
Saturday, May 3, 2014 at 8:51pm

Chemistry
Fuel pellets are replaced in a nuclear reactor when the U-238 content drops to A. 4% B. 6% C. 50% d. 94%
Saturday, May 3, 2014 at 6:49pm

Chemistry
Having trouble with this question on my homework =/ 200mL of 0.5M H2SO4 is combined with 500mL of 0.1M NaHCO3. List the physical states of all products, give molarity of aqueous ions and grams of gases and solids. Thanks alot guys!! Any help is awesome
Saturday, May 3, 2014 at 4:30pm

Chemistry
How many grams of lithium fluoride must be added to 3.5 kg of water to make a solution with a molality of 2.0 molal?
Saturday, May 3, 2014 at 4:21pm

Chemistry
Im not exactly sure what how to solve this with the way my teacher asked this question. "For hydrogen atom transitions calculate E, v, and wavelength:" Ni= 1 li= 0 Mli= 0 Msi= -1/2 Nf= 2 Lf= 0 Mlf= 0 Msf= -1/2 E(kj)= ? v(Hz)= ? wavelength(m)= ?
Saturday, May 3, 2014 at 4:03pm

Chemistry
Please help me solve this empirical formula.Im so confused C=58.5% H=4.1% N=11.4% and O=26.0% Thank you so much
Saturday, May 3, 2014 at 3:50pm

Chemistry - Science (Dr. Bob222)
Ammonium metavanadate reacts with sulfur dioxide in acidic solution as follows (hydrogen ions and H2O omitted): xVO3^–^ + ySO2 → xVO^2+^ + ySO4^2–^ What is the ratio of x : y? A. 1 : 1 B. 1 : 2 C. 2 : 1 D. 1 : 3 E. 3 : 1
Saturday, May 3, 2014 at 12:14pm

Chemistry
How many moles of H2O are in 254 milligrams of water?
Saturday, May 3, 2014 at 12:11pm

Chemistry - Science (Dr. Bob222)
Use the following information to answer this question: Cu+(aq) + e- → Cu(s) E° = 0.521V Cu2+ (aq) + e- → Cu+ (aq) E° = 0.153 V. Given these half cell reactions, an aqueous solution of Cu+ ion in the absence of O2(g) : A. will be thermodynamically stable B. ...
Saturday, May 3, 2014 at 11:38am

chemistry - Science
A zinc-copper battery is constructed as follows (standard reduction potentials given below): Zn | Zn2+ (0.10 M) || Cu2+ (2.50 M) | Cu Zn2+ + 2 e- → Zn(s) Eº = -0.76 V Cu2+ + 2 e- → Cu(s) Eº = 0.34 V The mass of each electrode is 200 g. Each half-cell ...
Saturday, May 3, 2014 at 11:23am

chemistry - Science
A zinc-copper battery is constructed as follows (standard reduction potentials given below): Zn | Zn2+ (0.10 M) || Cu2+ (2.50 M) | Cu Zn2+ + 2 e- → Zn(s) Eº = -0.76 V Cu2+ + 2 e- → Cu(s) Eº = 0.34 V The mass of each electrode is 200 g. Each half-cell ...
Saturday, May 3, 2014 at 7:30am

Chemistry - Science
A fuel cell designed to react grain alcohol with oxygen has the following net reaction: C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l) The maximum work that 1 mol of alcohol can yield by this process is 1320 kJ. What is the theoretical maximum voltage this cell can achieve?
Saturday, May 3, 2014 at 7:06am

chemistry
How much energy in MeV is released to form one atom of 87Rb from protons, electrons, and neutrons if the nucleus has a mass of 86.909187 amu? The masses of the proton, electron and neutron are 1.00728 amu, 0.000549 amu and 1.00867 amu, respectively. 1.602x10-13 J = 1 MeV; 1 ...
Friday, May 2, 2014 at 11:10pm

chemistry
I have two questions regarding enthalpy of reactions: 1.) Care must be taken when dissolving NaOH pellets in water because the temp. can rise dramatically. Taking NaOH as system, what can be deduced about the signs of the entropy of system and surroundings? Am I correct in ...
Friday, May 2, 2014 at 9:07pm

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