Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
50.0 mL of 0.116 M NaOH is titrated with 0.0750 M HCl. Calculate the pH after the addition of 5.0 mL volume of acid.
Wednesday, May 1, 2013 at 12:33am

chemistry
Three metals, iron, copper, and gold, have heat capacities of 0.450 J/goC, 0.385 J/goC and 0.129 J/goC, respectively. A 10g sample of each metal was heated in a water bath at 100oC. One of these metals will be placed in a Styrofoam cup containing 50.0 mL of water at 25oC. ...
Wednesday, May 1, 2013 at 12:23am

CHEMISTRY HELP!!!
21. Classify the following solutions in order of increasing pH: a. 0.01 M NaOH b. pure water c. 0.10 M HCl d. 0.05 M NaOH e. 0.001 M HCl
Wednesday, May 1, 2013 at 12:21am

Chemistry
dilute the concentration of 100mL of KIO3 from 0.5M to 0.0005M
Wednesday, May 1, 2013 at 12:16am

Chemistry
1. Chemists define pH as "the negative logarithm of the concentration of protons". In mathematical terms: pH = - log [H+] What is the pH of a solution whose [H+] is 0.0007 M? i got it as 7.0 i know it is wrong 2. What is the [H+] in a solution having a pOH of 6 ? isn...
Tuesday, April 30, 2013 at 11:21pm

Chemistry
I just to know how to identify the substance that is reduced, the substance that is oxidized, the oxidizing agent and the reducing agent in each reaction. As (s) + ClO3-(aq) → H3AsO3 (aq) + HClO(aq) CN-(aq) + MnO4-(aq) → CNO-(aq) + MnO2(s) C2H5OH + MnO4- → ...
Tuesday, April 30, 2013 at 11:01pm

chemistry
a block of aluminum is placed in 10.0g of water. the initial temperature of the water is 22.0 degrees celcious and its final temperature is 27.0 degrees celcious. what is the amount of heat released by the block of aluminum in calories if it had an initial temperature of 48.0 ...
Tuesday, April 30, 2013 at 10:11pm

Chemistry
A Cu/Cu^2+concentration cell has a voltage of 0.22v at 25 C. The concentration of Cu^2+ in one of the half cells is 1.5x10^-3 M. What is the concentrate of Cu^2+ in the other half cell? I think I will have to use Nernst equation, but I am so stuck! please help. Thank you so much.
Tuesday, April 30, 2013 at 9:44pm

Chemistry
I am having trouble with this equation and calculating the enthalpy of formation. 2 NaHCO3 (s) --> Na2CO3 (s) + H2O (g) + CO2 (g) delta H129.2kj I get as far as this step and then I don’t know what to do next. delta H= [1*delta H (Na2CO3) + 1* delta H(H2O (g)) + 1* ...
Tuesday, April 30, 2013 at 9:27pm

chemistry, stoichiometry
Consider the Balanced Chemical Equation 2N2+6H20-->4NH3+3O2 How many moles would be needed to react fully with 0.225 moles of N2?
Tuesday, April 30, 2013 at 9:13pm

chemistry
what is the molal concentration of tin in a solution of 5.000g of tin dissolved in 95.00 g of copper?
Tuesday, April 30, 2013 at 9:10pm

chemistry
What is the final pressure gas sample that is subjected to a temperature change from 22.0 C to 30.0 C and a volume change from 85.4 L to 37.0 L with an initial pressure 105 kPa?
Tuesday, April 30, 2013 at 8:51pm

Chemistry Help
How many moles of butane do we need to produce 10 moles of CO2 by reaction with oxygen? I think the balanced equation is 2 C4H10 + 13 O2 -----> 8 CO2 + 10 H2O
Tuesday, April 30, 2013 at 8:23pm

AP Chemistry
How many moles of butane do we need to produce 10 moles of CO2 by reaction with oxygen? I think the balanced equation is 2 C4H10 + 13 O2 -----> 8 CO2 + 10 H2O
Tuesday, April 30, 2013 at 7:54pm

Chemistry
Calculate the solubility of CuSO4 5H2O at 0 C in grams of solute per 100 g water.
Tuesday, April 30, 2013 at 7:42pm

Chemistry
Use the data from this table of thermodynamic properties to calculate the maximum amount of work that can be obtained from the combustion of 1.00 moles of ethane, CH3CH3(g), at 25 °C and standard conditions. I absolutely have no idea what to do, please help me!
Tuesday, April 30, 2013 at 7:38pm

Chemistry
Calculate the solubility of CuSO4 5H2O at 0 C in grams of solute per 100 g water.
Tuesday, April 30, 2013 at 7:23pm

chemistry
can you convert the grams to liters of water using the conversion factor of 22.4 liters in one mole?
Tuesday, April 30, 2013 at 7:17pm

chemistry
Is benzophenone soluble in phosphoric acid?
Tuesday, April 30, 2013 at 7:09pm

Chemistry II
Arrange the following 0.10M solutions in order of increasing pH: a. Nacl b. NH4CL C. HCL D. NaCH3CO2 e. KOH
Tuesday, April 30, 2013 at 5:31pm

chemistry
if 500 g of mgcl2 are produced in the above reaction how many l of h2 are produced
Tuesday, April 30, 2013 at 4:34pm

Chemistry
For a solution of 3.3 M H2CO3 (Ka = 4.4 × 10-7), calculate: (a) [H+] ____?______M (b) pH _____??______ (c) percent ionization ______?______%
Tuesday, April 30, 2013 at 4:06pm

Chemistry
For a particular reaction at 195.1 °C, ΔG = -1488.09 kJ/mol, and ΔS = 288.67 J/(mol·K).? Calculate ΔG for this reaction at -20.0 °C. delta G = delta H - (T*delta S) -1488.09 kJ/mol = (delta H) - ((461.8K)*(+288.67 J/(mol x K))*(1 kJ/1000 J)) -1488...
Tuesday, April 30, 2013 at 4:01pm

Chemistry
DrBob222, I don't know how to solve this problem either. And yes, this is the question for this problem. I even double check it. Please help. Chloroform (CHCL3) has a normal boiling point of 61 'C and an enthalpy of vaporization of 29.24 kJ/mol. What is the value of ...
Tuesday, April 30, 2013 at 3:52pm

College chemistry
The pH of blood is 7.4 and that of saliva is 6.4. what is the difference in pH between these two solutions? How much more Hydronium ion (H3O+) is in the saliva than in the blood. I need a detailed answer with the formulas if you can. I have a hard time with chemestry
Tuesday, April 30, 2013 at 3:38pm

Chemistry
The pK3 of formic acid is 3.75 A)what is the pH of a buffer in which formic acid and sodium formate have equimolar concentration? B)what is the pH of a solution in which the sodium formate is 10M and the formic acid is 1M?
Tuesday, April 30, 2013 at 1:50pm

Chemistry
Consider 18.0 M H2SO4, if you need to make 250.0 mL of a 3.0 M solution of H2SO4, how would you do this? 18.0 M H2SO4 has a density of 1.84g/mL what is the molality of solution? Mass % of H2SO4 in the solution and the mol fraction of H2SO4 and water in the solution?
Tuesday, April 30, 2013 at 1:50pm

Chemistry
What should be the number of significant figures in the following calculation? It's an error calculation which is absolute value (True value - experimental value) / true value * 100 so it would be: absolute value [-601.7 - (-587)] / -601.7 * 100 Should the answer be 2.44 ...
Tuesday, April 30, 2013 at 1:13pm

Chemistry
If 20 grams of sulfur reacts with an excess of oxygen, what volume of the product SO2 would be collected at 108.5 kPa and 15 degrees Celseius?
Tuesday, April 30, 2013 at 11:12am

chemistry: please check answers.
1. How many valence electrons does a carbon atom have? A) 1 B) 2 C) 3 D) 4<<my answer 2. How many double covalent bonds are in an alkane? A) 0<<my answer B) 1 C) 2 D) 3 3. What is the general formula for a straight-chain alkane? A) CnHn B) CnHn+2 C) CnH2n D) CnH2n+...
Tuesday, April 30, 2013 at 10:30am

chemistry
A gas is stored in a 3.5L container at 15 degrees celsius and 655mmHg. Calculate the number of moles of the gas in the container
Tuesday, April 30, 2013 at 10:17am

Chemistry
The balanced equation for the decomposition of sodium bicarbonate is 2 NaHCO3 (s) --> Na2CO3 (s) + H2O (g) + CO2 (g)delta H 129.2. Using the enthalpies of formation, calculate the enthalpy of formation of sodium bicarbonate.
Tuesday, April 30, 2013 at 10:02am

grade 12 chemistry
explain the concept of a “stock solution” and standard solutions as if you were explaining it to a friend who is not studying chemistry.
Tuesday, April 30, 2013 at 3:18am

chemistry
why do different compounds give different retention factors (Rf values) in thin layer chromatography (TLC)
Tuesday, April 30, 2013 at 3:17am

chemistry university
In this experiment you will be placing solid CO2 into a 10 ml tube. The tubes are not completely gas-tight, but what if they were? What would be the pressure inside the tube in atm, after all the dry ice had vapourised, if 3.72 g of solid CO2 was originally added and the tube ...
Tuesday, April 30, 2013 at 2:33am

Chemistry 1
if 0.500mol of argon gas occupies 2.10L at 735mmHg, what is the temperature if degrees Celsius
Tuesday, April 30, 2013 at 2:23am

Chemistry
Chloroform (CHCL3) has a normal boiling point of 61 'C and an enthalpy of vaporization of 29.24 kJ/mol. What is the value of delta Gvap (in kJ) at 61'C for chloroform?
Tuesday, April 30, 2013 at 1:42am

Chemistry
The following thermodynamic data was obtained for an unknown compound. Delta Hvap = 31.3 kj/mol and Delta S Vap= 79.7 kj/mol .Calculate the normal boiling point of this compound in Celcius.. Thank you! Chemistry - DrBob222, Tuesday, April 30, 2013 at 12:31am dG = dHvap - ...
Tuesday, April 30, 2013 at 1:25am

Chemistry
At 20 degree celsius, Ka for an unknown monoprotic weak acid is 0.00088. Calculate the Delta G (in kJ/mol) for the reaction of this unknown acid with water. HA(aq) + H2O(l) <--> H3O+(aq) + A-(aq)
Tuesday, April 30, 2013 at 1:00am

chemistry
which of these would have the highest melting point due to the trong intermolecular forces, CH2 NH2 H2 CO2?
Tuesday, April 30, 2013 at 12:29am

chemistry
Pipette 3 drops of oil into a test tube of water and shake. Describe what takes place and why? - Would it be the oil settles at the top of the water, because the oil is less dense, and its a non-polar substance, so it doesn't mix with a polar substance (water). Add 1 scoop...
Tuesday, April 30, 2013 at 12:28am

chemistry
Consider 18.0 M H2SO4, if you need to make 250.0 mL of a 3.0 M solution of H2SO4, how would you do this? 18.0 M H2SO4 has a density of 1.84g/mL what is the molality of solution? Mass % of H2SO4 in the solution and the mol fraction of H2SO4 and water in the solution?
Monday, April 29, 2013 at 11:40pm

chemistry
How do you calculate deltaHf using the # of moles from a balanced equation? How do you connect the Law of Conservation of Energy to a Thermochemical Equation? Thanks so much!
Monday, April 29, 2013 at 11:40pm

chemistry
Calculate the enthalpy of fusion of naphthalene (C10H8) given that its melting point is 128 Celsius and its entropy of fusion is 47.7 J (k*mol) .
Monday, April 29, 2013 at 10:39pm

Chemistry
imagine that you have a 100 ml of HCl, after adding 50 ml of 1M NaOH, how many moles of OH did you add
Monday, April 29, 2013 at 10:33pm

chemistry
Given that for the vaporization of benzene Hvap= 30.7 kj/mol and Svap= 87.0 J(K * mol) , calculate Delta G (in kJ/mol) for the vaporization of benzene at 13 Celcius.
Monday, April 29, 2013 at 10:29pm

Chemistry
imagine that you have a 100 ml of HCl, after adding 50 ml of 1M NaOH, how many moles of OH did you add
Monday, April 29, 2013 at 10:07pm

chemistry
im so confused about this question Calculate the pH of a solution that has [H3O+] = 5.5 x 10-3.
Monday, April 29, 2013 at 10:02pm

chemistry
If you made up a solution of NaOH by adding 0.010 mole of solid NaOH to 1.0 liter of distilled water, what would be the concentration of the OH-(aq)?
Monday, April 29, 2013 at 5:59pm

chemistry
If the density of pure acetic acid is 1.005g/cm, what is it molarity
Monday, April 29, 2013 at 4:57pm

chemistry
How many grams of ethylene glycol must be added to 37.8g of water to give a freezing point of -0.150 degrees Celsius
Monday, April 29, 2013 at 4:16pm

B
For a solution of 3.3 M H2CO3 (Ka = 4.4 × 10-7), calculate: (a) [H+] ____?______M (b) pH _____??______ (c) percent ionization ______?______%
Monday, April 29, 2013 at 4:00pm

Chemistry revision
all these questions I got wrong on my homework today ...I'm trying to find out why and what the correct answers were .. please help How many grams of solute are required to make a 504 mL solution of copper (I) nitrate with a concentration of 1.3317 M? before I had help and...
Monday, April 29, 2013 at 2:32pm

chemistry
Al2(SO4)3+6KOH-->2Al(OH)3+3K2SO4 a)How many grams of potassium hydroxide are needed to completely react with 870 mg of aluminum sulfate? b)If you want to make 7.00 grams of potassium sulfate, how many grams of aluminum sulfate would you need to react? c)How many grams of ...
Monday, April 29, 2013 at 2:30pm

Chemistry
A student mixes 450 mL of water and 116 mL of 7.90 x 10-5 M greenfood dye solution. What is the concentration of this new dilute solution of green food dye?
Monday, April 29, 2013 at 2:17pm

chemistry
49-kg woman cheats on her diet and eats a 582-Calorie (582 kcal) jelly doughnut for breakfast. (a) How many joules of energy are the equivalent of one jelly doughnut? J (b) How many stairs must the woman climb to perform an amount of mechanical work equivalent to the food ...
Monday, April 29, 2013 at 11:06am

chemistry
The pressure in a constant-volume gas thermometer is 0.700 atm at 100°C and 0.512 atm at 0°C. (a) What is the temperature when the pressure is 0.0500 atm? °C (b) What is the pressure at 405°C? atm
Monday, April 29, 2013 at 10:55am

Chemistry
Hydrogen bromide gas, a polar covalent compound, is very soluble in water. Describe what happens, referring to intermolecular forces, as the hydrogen bromide dissolves. Diagrams may be helpful in your explanation. I need help with this question for assignment. Please and Thank...
Monday, April 29, 2013 at 9:11am

chemistry
a)Name two cations whose salts are quite soluble in water? b)Name one anion whose salts are soluble in water.?
Monday, April 29, 2013 at 5:06am

Chemistry
23.55 ml of the NaOH were added to partially neutralize a new 25.00 ml sample of the acid. The pH of the mixture was measured as 5.33. Calculate Ka for the acid, HA, using the partial neutralization method
Monday, April 29, 2013 at 5:00am

Chemistry
What is the pH of a solution prepared by mixing 50.00 mL of 0.10 M NH3 with 25.00 mL of 0.10 M NH4Cl? Assume that the volume of the solutions are additive and that Kb= 1.8 × 10-5 for NH3.
Monday, April 29, 2013 at 3:35am

Chemistry
A solution of H2SO4(aq) with a molal concentration of 1.66 m has a density of 1.104 g/mL. What is the molar concentration of this solution?
Monday, April 29, 2013 at 12:59am

Chemistry
A solution is made by dissolving 0.624 mol of nonelectrolyte solute in 795 g of benzene. Calculate the freezing point and boiling point of the solution. Tf=_ˆC Tb=_ˆC
Monday, April 29, 2013 at 12:56am

Chemistry
A 1.50 L portion of 0.100M sulfamic acid, HSO3NH2, is placed in the bottom of a 10.0 L glass lined stainless steel chamber. A dish containing 17.25g of solid NaNO2 is floated on the acid. A thin open ended U tube containing a pool of liquid mercury is connected to the chamber ...
Sunday, April 28, 2013 at 10:45pm

chemistry
C3H8(g)+5O2(g)-->3CO2(g)+4H2O(l) what reactant is oxidized and which is reduced?
Sunday, April 28, 2013 at 10:28pm

ap chemistry
We drop 50.5 grams of magnesium into 572 mL of a 3 M HCl solution. What is the maximum volume of dry hydrogen that could be produced by this reaction at STP?
Sunday, April 28, 2013 at 10:10pm

Chemistry
If 10.5 g of hydrogen,H2, were mixed with 6.51 g of acetylene, C2H2, and allowed to react according to the following equation, what is the theoretical yield of ethane, C2H6, produced? If 7.00 g of ethane, C2H6, were recovered at the end of the reaction, what is the percent ...
Sunday, April 28, 2013 at 9:52pm

chemistry
if 8.00 mol of NH3reacted with O2 how many moles of H2O will be produced? 4NH3(g) + 7O2(g) -> 4NO2 + 6H2O(g)
Sunday, April 28, 2013 at 9:52pm

chemistry
how many grams of CO are needed to react with an excess of Fe2O3 to produce 201.1 g Fe? Fe2o3(s) + 3CO(g) -> 3CO2(g) + 2Fe(s)
Sunday, April 28, 2013 at 9:46pm

Chemistry
Hydrogen bromide gas, a polar covalent compound, is very soluble in water. Describe what happens, referring to intermolecular forces, as the hydrogen bromide dissolves. Diagrams may be helpful in your explanation. Please, I need help with this question for assignment.
Sunday, April 28, 2013 at 9:21pm

chemistry
The temperature of an ideal gas in a 5.00 L container originally at 1.01 bar pressure and 25 °C is lowered to 220 K. Calculate the new pressure of the gas.
Sunday, April 28, 2013 at 8:48pm

chemistry
Finding out if the amount of heat produced depends on an increase in the concentration of Hcl
Sunday, April 28, 2013 at 6:36pm

chemistry
Finding out if the amount of heat produced depends on an increase in the concentration of Hcl
Sunday, April 28, 2013 at 6:30pm

Chemistry-Pressure
The wastewater solution from a factory containing high levels of salts needs to be diluted before it can be released into the environment. Therefore, two containers of waste solution are separated by a semipermeable membrane and pressure is applied to one container, forcing ...
Sunday, April 28, 2013 at 5:47pm

chemistry (Pls Bob check for me)
what mass of 25% ba(n03)2 solution contain 40 grams of ba(n03)2 ? Answer 160g My calculation 40g/261.37g/mol = 0.15305/0.25g = 0.612 This answer is not right Who helps
Sunday, April 28, 2013 at 5:14pm

Chemistry
A current of 2.34 A is delivered to an electrolytic cell for 85 minutes. How many grams of Au will be deposited from an aqueous solution of AuCl3?
Sunday, April 28, 2013 at 4:57pm

Chemistry
A current of 2.34 A is delivered to an electrolytic cell for 85 minutes. How many grams of Au will be deposited from an aqueous solution of AuCl3?
Sunday, April 28, 2013 at 4:20pm

Chemistry
A sample of gas is confined to a cylinder housed with a movable piston. Initially, the gas occupies a volume of 2.7 L at 6.0 atm and 25°C. Calculate the volume of the gas sample if the pressure is reduced to 1.8 atm and the temperature decreased to 20°C.
Sunday, April 28, 2013 at 4:10pm

chemistry
If 13.5 ml of concentrated (17.0 M) of sulfuric acid was spilled on the chemistry counter, calculate the mass of sodium bicarbonate needed to neutralize the acid
Sunday, April 28, 2013 at 2:33pm

chemistry (Pls Bob check for me)
Aspirin c9h8oh molar mass = 180.1g/mol can be prepared by the reaction of salicylic acid c7h603 molar mass = 13801 g/mol with acetic anhydride c6h603, according to the following equation. A chemist starts with 2 gram of salicylic acid reacts it with excess acetic anhydrate, ...
Sunday, April 28, 2013 at 2:28pm

chemistry
The following reaction was carried out in a 2.00 reaction vessel at 1100 : C+H2O -> C)+H2 If during the course of the reaction, the vessel is found to contain 7.00mol of C, 13.3mol of H2o, 3.80mol of CO, and 7.20mol of H2, what is the reaction quotient ? Enter the reaction ...
Sunday, April 28, 2013 at 2:13pm

chemistry (charles law)
A 4.0L sample of methane gas is collected at 30.0 celcius .predict the volume of the sample at 0 celcius.
Sunday, April 28, 2013 at 1:05pm

chemistry (charles law)
1.)A ballon is filled with 3.0L of helium at 310k.The balloon is placed in an oven where the temputure reaches 340k.what is the new volume of the ballon?
Sunday, April 28, 2013 at 1:00pm

Chemistry
Aluminium react with oxygen to form aluminium oxide.how many grams of potassium chlorate V would be heated to produce enough oxygen to form 5.1grams of aluminium oxide
Sunday, April 28, 2013 at 10:36am

chemistry
A specimen of LaNi5 containing hydrogen is placed in a vacuum furnace. After 1 hour, at what depth from the surface of the specimen has the concentration of hydrogen reached 1/3 the initial concentration? The diffusion coefficient of hydrogen in the alloy has a value of 3...
Sunday, April 28, 2013 at 6:34am

chemistry
acetaldehyde Ch3Cho will decomposed into methane and CO according to Ch3Cho->ch4+Co at 450 C the rate consumption of Ch3cho is measured to vary with the concentrate of heliumCh3Cho raised to the power 1.5 with a Ch3Cho concentrate of 0.222 M ,the rate of consumption of ...
Sunday, April 28, 2013 at 6:12am

chemistry
to reduce loss of helium , a pressure vessel is lined with a membrane made of tantalum.the concentrate of helium at the inner surface of the membrane is held constant at 4.44*10^-5kg/cm3, which the concentrate at the outer surface of the membrane is held constant at ...
Sunday, April 28, 2013 at 6:00am

chemistry
Calculate the density of atoms in (011) in lithium (Li). Express your answer in units of atoms/cm2.
Sunday, April 28, 2013 at 6:00am

chemistry
Which of the following will increase the strength of a sample of 90% SiO2 - 10% MgO Quench the entire sample in water Quench half of the sample in water Cool the entire sample with air jets Cool half the sample with air Submerge the sample in a salt bath of Na2O Submerge the ...
Sunday, April 28, 2013 at 5:57am

chemistry
consider an x-ray tube with a Cun anode and a monochromator consisting of a Ni single crystal with (111) planes parallel to surface of crystal. what is the lowest voltage capable of producing X-rays trough a monochromator ? answer in V.
Sunday, April 28, 2013 at 5:47am

chemistry
N Type silicon has been produced by doping with (P).the charge carrier population based on electrical conductivity measurement is determined to be 3.091*10^17 carriers/cm3 at room temperature. calculate doping level of P (how much P has been added to the silicon) express your ...
Sunday, April 28, 2013 at 5:39am

chemistry
a sample of molybdenum is analysed by x-ray diffraction using Nik(alpha) radiation. calculate value of angle of which the lowest angle of radiation is observed . answer in degrees.
Sunday, April 28, 2013 at 5:31am

chemistry
How to compare the melting point of two ionic bod or two covalent bond?
Sunday, April 28, 2013 at 4:48am

chemistry
why does MgO has a higher boiling and melting point than NaCl?
Sunday, April 28, 2013 at 4:47am

chemistry
the youngs modulus for the steel is 20.7*10^10 N/m2,how much will a 2.5 mm diameter wire 12 cm long, be strained when it support a load of 450 N? express strain as decimal not a %
Sunday, April 28, 2013 at 3:12am

chemistry
the energy of vacancy formation in palladium is 1.5 eV.at 888 C there is one vacancy formation for every million (10^6) atoms sites. what temperature would be achieved a vacancy fraction of one for every thousand (10^3)atoms sites?
Sunday, April 28, 2013 at 3:01am

chemistry
a chemical analysis that silicon crystal weighing 100 gm containing 16.5 mg of aluminium which is substitutionally incorporated (the aluminium atoms replaced some of the silicon atom) what is the number of extrinsic charge carriers in this crystals? answer in carriers/cm3
Sunday, April 28, 2013 at 2:51am

chemistry
calculate density of atoms in(001) in Lithium answer in units of atoms/cm2
Sunday, April 28, 2013 at 2:38am

chemistry
Estimate the fraction of unoccupied atomic sites in lead at temperature 10K below its melting point. Vacancy fraction,nv/N temperature 1.8*10^-7 100C 7.2*10^-6 200C express answer in vacancy fraction nv/N.
Saturday, April 27, 2013 at 11:41pm

Chemistry
Arsenic acid has the formula H^3AsO^4. It is a triprotic acid. Abottle is marked 0.422 N arsenic acid. What is the Molarity of this solution?
Saturday, April 27, 2013 at 9:47pm

Chemistry
How much mL of 0.2 M NaOH are needed to titrate vinegar while doing a titration with Phenolphthalein?
Saturday, April 27, 2013 at 7:50pm

chemistry
In the following options which one is maximum/highly exothermic reaction..? 1)SrO+h2o 2)BaO+h2o 3)CaO+h2o 4)MgO+h2o Pls.... Need it real quick
Saturday, April 27, 2013 at 5:15pm

chemistry
Which direction would equilibrium shift in the reaction N2 + 3H2 2NH2 + 22,000 cal if it is cooled?
Saturday, April 27, 2013 at 1:38pm

chemistry
Estimate the fraction of of unoccupied atomic sites in lead (Pb) at a temperature 10K below its melting point. DATA: Vacancy Fraction, nv/N T (degrees C) 1.8*10-7 100 7.2*10-6 200 Express your answer in terms of vacancy fraction, nv/N:
Saturday, April 27, 2013 at 1:35pm

Chemistry
How many grams of CaCl2 would be required to produce a 3.5M(molar) solution with a volume of 2.0L?
Saturday, April 27, 2013 at 1:27pm

Chemistry
Calculate the percent ionization of 0.140 M lactic acid in a solution containing 8.5×10−3 M sodium lactate.
Saturday, April 27, 2013 at 12:27pm

Chemistry
The energy of vacancy formation in palladium (Pd) is 1.5 eV. At 888C there is one vacancy for every million (106) atom sites. What temperature would be necessary to achieve a vacancy fraction of one for every thousand (10 3) atom sites?
Saturday, April 27, 2013 at 11:18am

chemistry
The solubility of the fictitious compound, administratium fluoride (AdF3) in water is 3.091×10−4 M. Calculate the value of the solubility product Ksp.
Saturday, April 27, 2013 at 11:06am

chemistry
Calculate the density of atoms in (001) in lithium (Li). Express your answer in units of atoms/cm2. incorrect
Saturday, April 27, 2013 at 10:11am

Chemistry
A sample of argon gas at STP occupies 56.2 liters. Find the number of moles of argon and the mass in the sample
Saturday, April 27, 2013 at 9:39am

chemistry
a 2.3% (m/v) LiCI solution p;repared from 53.0 ml of a 10.0%(m/v)LiCI solution. what is volume in milliliters
Saturday, April 27, 2013 at 7:46am

Chemistry
Consider the titration of 50 mL of 0.250 M HCl with 0.1250 M NaOH. Calculate the pH of the resulting solution after the following volumes of Na OH have been added. a) 0.00 mL b) 50.00 mL c) 99.90 mL d) 100.00 mL e) 100.1 mL The question is, I get, for example, 0.9 pH for "...
Saturday, April 27, 2013 at 3:02am

Chemistry
Why does the titration of terephthalic acid yield a mass of approximately half the molar mass?
Saturday, April 27, 2013 at 2:35am

Chemistry
Which of the following will increase the strength of a sample of 90% SiO2 - 10% MgO Quench the entire sample in water Quench half of the sample in water Cool the entire sample with air jets Cool half the sample with air Submerge the sample in a salt bath of Na2O Submerge the ...
Saturday, April 27, 2013 at 1:52am

chemistry
If a sample of NH4NO3 contained 5.04 x 1022 hydrogen atoms, how many moles of NH4NO3 are in your sample?
Saturday, April 27, 2013 at 12:46am

inorganic chemistry
what is the product of reaction dehydrated K3(Al(C2O4)3) with KMnO4 in the present of KOH?
Saturday, April 27, 2013 at 12:30am

Chemistry
To illustrate the calculation, assume that 21.95 mL of a thiosulfate solution is required to reduce the iodine liberated by 20.85 mL of 0.0200M KIO3 and that 18.63 mL of the same thiosulfate solution reacts with the iodine replaced by 20.00 mL of an unknown solution of sodium ...
Friday, April 26, 2013 at 8:24pm

chemistry
Suppose that you did not completely convert the hydrate to dehydrate compound. Explain how would this affect the calculated percent by mass of water in a compound.
Friday, April 26, 2013 at 7:25pm

CHEMISTRY
Do you think it is more useful to have the percent by mass of water in hydrate or the percentage composition, assuming that you know the formula for the associated dehydrated compound? Can someone please explain what's the meaning of this question, I'm confuse. Thanks!
Friday, April 26, 2013 at 7:10pm

chemistry
What is the plane and lattice structure that is represented in this picture? SC (100) BCC (100) FCC (100) SC (110) BCC (110) FCC (110) SC (111) BCC (111) FCC (111)
Friday, April 26, 2013 at 6:25pm

chemistry (need by 5!!)
use the van der waals equation to calculate the pressure of 4.00 mol of H20 at 471K in a 4.60-L vessel. how do you solve?
Friday, April 26, 2013 at 4:33pm

chemistry
In a gas mixture, the partial pressures are argon 393 mm Hg, neon 73 mm Hg, and nitrogen 119 mm Hg. What is the total pressure (atm) exerted by the gas mixture?
Friday, April 26, 2013 at 3:57pm

Chemistry
How much ice (in grams) would have to melt to lower the temperature of 53.4g of water from 65 C to 0C? I know there are more than one step here, I would appreciate an answer that does not do the work for me, but show me how to lay out the problems and in which order... thank you!
Friday, April 26, 2013 at 3:15pm

organic chemistry isomers
which of the following molecules has a conformational isomer? CHCH CH2CH2 CH3CH2CH2CH3 CH2CCCH2 I think its either 2 or 4 but leaning towards 4. I just need help being more confident in my answer.
Friday, April 26, 2013 at 2:37pm

chemistry
The energy of vacancy formation in palladium (Pd) is 1.5 eV. At 888C there is one vacancy for every million (106) atom sites. What temperature would be necessary to achieve a vacancy fraction of one for every thousand (10 3) atom sites? Express your answer in degrees C:
Friday, April 26, 2013 at 2:08pm

chemistry
The Young’s modulus for steel is 20.7*1010 N/m2. How much will a 2.5 mm diameter wire 12 cm long, be strained when it supports a load of 450 N? Aluminum’s Young’s modulus is 6.9*1010 N/m2. Express the strain as a decimal, not a percentage What diameter of ...
Friday, April 26, 2013 at 10:57am

chemistry
Acetaldehyde, CH3CHO, will decompose into methane and carbon monoxide according to CH3CHO (g) -> CH4 (g) + CO (g) At 450C the rate of consumption of CH3CHO is measured to vary with the concetration of CH3CHO raised to the power 1.5. With a CH3CHO concentration of 0.222M, ...
Friday, April 26, 2013 at 10:56am

chemistry
To reduce the loss of helium, a pressure vessel is lined with a membrane made of tantalum. The concentration of helium at the inner surface of the membrane is held constant at 4.44*10-5 kg/m3, while the concentration at the outer surface of the membrane is held constant at ...
Friday, April 26, 2013 at 10:55am

chemistry
Glass A has a composition of 90% SiO2 - 10% Na2O. Glass B has a composition of 99% SiO2 - 1% Na2O. Both glasses are cooled to room temperature at the same rate. (a) Which glass has the higher Tg? Glass A Glass B (b) Which glass has the lower free volume?
Friday, April 26, 2013 at 10:53am

chemistry
Which of the following will increase the strength of a sample of 90% SiO2 - 10% MgO
Friday, April 26, 2013 at 10:53am

Chemistry
If 10.5 g of hydrogen, H2, were mixed with 6.51 g of acetylene, C2H2, and allowed to react according to the following equation, what is the theoretical yield of ethane, C2H6, produced? If 7.00 g of ethane, C2H6, were recovered at the end of the reaction, what is the percent ...
Friday, April 26, 2013 at 9:26am

'A'level chemistry
Plot a phase diagram of NaCl solution ,the minimum depression is 23 degrees celcious at concentration 5mol/dm-3. (I)concentration of NaCl(mol/dm-3) 0,6 ;1,2;2,2;3,5 freezing point depression (degrees celcious 2,0;4,0;8,0 ;14,0
Friday, April 26, 2013 at 5:14am

chemistry
The reaction x products follows Ist order kinetics in 40 minutes the concetration of x changes from 0.1M to 0.025M then the rate of reaction when conc of x is 0.01
Friday, April 26, 2013 at 5:04am

Chemistry
Calculate the density of atoms on plane (001) in Lithium
Friday, April 26, 2013 at 2:25am

chemistry
N-type silicon (Si) has been produced by doping with phosphorus (P). The charge-carrier population based on electrical conductivity measurments is determined to be 3.091*1017 carriers/cm3 at room temperature. Calculate the doping level of P (how much P has been added to the Si...
Friday, April 26, 2013 at 2:16am

Chemistry
Calculate the density of atoms in (001) in lithium (Li)(units of atoms/cm2)
Friday, April 26, 2013 at 2:16am

chemistry
Consider an x-ray tube with a Cu anode and a monochromator consisting of a nickel single crystal with (111) planes parallel to the surface of the crystal. What is the lowest voltage capable of producing x-rays through a monochromator? Express your answer in V:
Friday, April 26, 2013 at 2:15am

chemistry
A sample of molybdenum (Mo) is analyzed by x-ray diffraction using NiK radiation. Calculate the value of the angle at which the lowest-angle reflection is observed. Express your answer in degrees:
Friday, April 26, 2013 at 2:15am

chemistry
A chemical analysis indicates that a silicon crystal weighing 100g contains 16.5 mg of aluminum (Al) which is substitution-ally incorporated (the Al atoms replace some of the Si atoms). What is the number of extrinsic charge carriers in this crystal? Express your answer as ...
Friday, April 26, 2013 at 2:10am

Chemistry
Calculate the molar solubility of MgCO3 in a solution that already contains 1.7×10−3 M sodium carbonate. MgCO3 Ksp = 6.82 x 10-6 IMPORTANT NOTE: You must use the quadratic equation to solve this problem. (DrBob222- thank you so much for all your help!)
Friday, April 26, 2013 at 1:54am

chemistry
Calculate the density of atoms in (001) in lithium. Express answer in atoms/cm.
Friday, April 26, 2013 at 1:29am

Chemistry
Lithium metal is a highly reactive metal that oxidizes instantly in water or air. Given the data below, calculate the energy required to heat 10.0 g of Li from 150.0 °C to 200.0 °C. Molar heat capacity (solid) = 3.58 J/°C • mol Molar heat capacity (liquid) = 4...
Thursday, April 25, 2013 at 11:53pm

Chemistry
Ethanol (C2H5OH) has been produced since antiquity by the fermentation of fruits and vegetables. Given the following data, if 5.87 kJ of energy are transferred to 13.3 g of frozen ethanol at -130.0 °C, what is the final temperature of the sample? Heat capacity (solid) = 0....
Thursday, April 25, 2013 at 11:52pm

chemistry
Given the thermochemical equation below, calculate the amount of energy released when 250. g of NaOH (molar mass = 40.0 g/mol) reacts with an excess of HCl. Report answer to the correct number of significant figures in units of kilojoules, kJ. NaOH + HCl --> NaCl + H2O ...
Thursday, April 25, 2013 at 9:31pm

Chemistry
What concentration of SO32– is in equilibrium with Ag2SO3(s) and 3.60 × 10-3 M Ag ? The Ksp is 8.46×10–12.
Thursday, April 25, 2013 at 9:05pm

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