Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
At 25 degrees C and 1 atm gas pressure, the solubility of CO2(g) is 149 mg/100 g water. When air at 25 degrees C and 1 atm is in equilibrium with water, what is the concentration of dissolved CO2, in mg/100 g water? Air contains 0.037 mol % CO2(g). the answer should come out ...
Monday, February 18, 2013 at 7:09pm

Chemistry
Define a.m.u?
Monday, February 18, 2013 at 5:53pm

Chemistry
Why is the enthalpy of the reactants greater than the enthalpy of the products in an exothermic reaction? If it has something to do with the reactants having weaker bonds, why do weaker bonds have higher energy/enthalpy? It doesn't really make sense to me that weaker bonds...
Monday, February 18, 2013 at 5:47pm

chemistry
N2(g)+3H2(g)<=>2NH3(g) +▲H if uou are preparing NH3, hiw does the following increase the yield of NH3? (a) ▲[N2] ▲[H2] (b) ▲T of the chamber storing NH3 (c) ▲P of the system (d) ▲[NH3(g)] * <=> equilibrium * ▲ change
Monday, February 18, 2013 at 5:04pm

chemistry
If 22.4 dm3 of steam react with MgO, calculate the mass of the product that will form.
Monday, February 18, 2013 at 4:52pm

Chemistry
How many cubic decimeters of oxygen are needed to react with sulfur to produce 5.00 * 103 cubic decimeters of sulfur dioxide?
Monday, February 18, 2013 at 4:51pm

chemistry
Calculate the mass of sliver chloride, AgCl, and dihydrogen monosulfide, H2S, formed when 85.6g of sliver sulfide, Ag2S, reacts with excess hydrochloric acid, HcL.
Monday, February 18, 2013 at 4:10pm

chemistry
Greg reacts 5.0 moles of hydrochloric acid(HCL)with 1.5 moles of barium hydroxide(Ba(OH)2).Which reagent is the limiting reagent, and which is in excess?If the reagent runs to completion,how many moles of barium chloride(BaCl2)will be produced? CAN SOMEONE PLEASE HELP ME....
Monday, February 18, 2013 at 4:04pm

Chemistry
Carbon dioxide dissolves in water to form carbonic acid, which is primarily dissolved CO2. Dissolved CO2 satisfies the equilibrium equation: CO2 (g) <----> CO2 (aq) K=0.032 The acid dissociation constants listed in most standard reference texts for carbonic acid actually...
Monday, February 18, 2013 at 3:17pm

Chemistry
At 20.0 degrees celcius, a student collects H2 gas in a gas collecting tube. The barometric pressure is 755.2mm Hg and the water levels inside and outside the tube are exactly equal. What is the total gas pressure in the gas collecting tube?
Monday, February 18, 2013 at 3:04pm

chemistry
I. 1) Calculate the pH of the following solution: 0.1 M HF + 0.2 M NaCN Given: pKa for: HF/F- = 3.2 HCN/CN-= 9.4 2) Calculate the pH of the solution that results upon mixing 20.0 mL of 0.2000 M HCI with 25.0 mL of: a) distilled water c) 0.13 MNaOH e) 0.23 MNaOH b) 0.13 M AgN03
Monday, February 18, 2013 at 2:10pm

Math - Please Help
While rummaging in his great aunt's attic, Bernard found a small figurine that he believed to be made out of silver. To test his guess, he looked up the denisty of silver in his chemistry book and found it to be 10.5 g/cm^3. He found that the figure had a mass of 149 g. To...
Monday, February 18, 2013 at 1:16pm

Chemistry
A solution has a hydroxide-ion concentration of 7.48X10-5 M. What is it's hydronium-ion centration? I have no idea where to begin on this question...
Monday, February 18, 2013 at 1:03pm

Chemistry
How many grams of oxygen are collected in a reaction where 247 mL of oxygen gas is collected over water at a temperature of 25°C and a total pressure of 697 torr? And would i just convert 697 torr into atm and use that for pressure? And how do i find the molar mass of the ...
Monday, February 18, 2013 at 12:36pm

Chemistry
It takes 200. seconds for a sample of carbon dioxide to effuse through a porous plug and 280. seconds for the same volume of an unknown gas to effuse under the same conditions. What is the molar mass of the unknown gas? Enter your answer to 3 significant figures.
Monday, February 18, 2013 at 11:56am

Chemistry
How many grams of oxygen are collected in a reaction where 247 mL of oxygen gas is collected over water at a temperature of 25°C and a total pressure of 697 torr?
Monday, February 18, 2013 at 11:55am

Chemistry
Define a.m.u?
Monday, February 18, 2013 at 10:08am

Chemistry
What is gaseous state?
Monday, February 18, 2013 at 10:05am

Chemistry
how can you prepare 300ml of 15% h2so4 solution
Monday, February 18, 2013 at 8:31am

Chemistry
In a given 1st order reaction A ---> products, the initial concentration of A is 0.40 M. What will be the concentration of A after 15 seconds if the half-life of the reaction is 3 seconds? I found the concentration to be 1.25 x 10-2 M But then how do I find the rate ...
Monday, February 18, 2013 at 7:37am

Chemistry
I have a cyclohexane with a 3 carbon chain coming off of it. and two methyl groups on the second carbon. what is it called :/
Monday, February 18, 2013 at 3:17am

chemistry
AMU ?
Monday, February 18, 2013 at 1:01am

Chemistry
2 SO2 (g)+O2 (g)→2 SO3↑ How many grams of SO3(g) are formed if 8.45 grams of oxygen are used?
Monday, February 18, 2013 at 12:37am

chemistry
Preceed the equation of CuSO4 + Fe
Monday, February 18, 2013 at 12:03am

Chemistry
A 62g piece of ice at 0 degrees celcius is added to a sample of water at 9 degrees celcius. All of the ice melts and the temperature of the water decreases to 0 degrees celcius. How many grams of water were in the sample
Sunday, February 17, 2013 at 11:57pm

chemistry
how much pb can be isolated from 3.5kg of pbco3?
Sunday, February 17, 2013 at 10:32pm

Chemistry
Currently studying for an lab exam. Just have a few question about a typical Iodine Clock reaction lab. In an typical Iodine Clock reaction lab what would be the state of effect of an increase in the initial concentration of persulfate ion and the increase in the initial ...
Sunday, February 17, 2013 at 10:11pm

Chemistry
find the molarity of 150. g H2SO4 solute dissolved into 900. g H2O solvent
Sunday, February 17, 2013 at 9:59pm

college chemistry
Assuming that 9.0\% of the energy output of a 65W lightbulb is visible light and that the average wavelength of the light is 550 {\rm nm}, how many photons are emitted by the lightbulb each second?
Sunday, February 17, 2013 at 8:50pm

Chemistry!
The heat lost or gained by a system is related to its temperature change by a property called its heat capacity. The molar heat capacity of metals at or above room temperature equals 24.92 J K-1mol-1. The temperature of a block of copper metal (molar mass 63.55 g mol-1) fell ...
Sunday, February 17, 2013 at 8:33pm

chemistry
A helium-ﬁlled balloon contains 143 mL of gas at a pressure of 0.99 atm. What volume will the gas occupy at standard pressure?
Sunday, February 17, 2013 at 8:08pm

Chemistry
I'm trying to write a sentence like this: Exothermic reactions have a negative enthalpy change value because the enthalpy of the reactants are greater than the enthalpy of the products since the reactants have weaker bonds.... Why do weaker bonds have higher energy/...
Sunday, February 17, 2013 at 7:30pm

Chemistry
If I have 50 mL of Lead(II) Nitrate, it is possible for me to calculate how many mole is 1 mL of the substance? Thanks
Sunday, February 17, 2013 at 7:19pm

chemistry
gaseous hydrogen and fluorine combine in the reaction above to form hydrogen fluoride with an enthalpy change of -540kJ. What is the value of the heat of formation of HF(g)
Sunday, February 17, 2013 at 6:14pm

Chemistry/Physics
I'm not sure how to do this. Determine the actual ratio of 18O:16O for the following substances. a) Snow falling in Greenland at a temperature of -20 degrees C b) Water vapor in equilibrium with VSMOW c) Pore-water from sediments in the North Atlantic corresponding to the ...
Sunday, February 17, 2013 at 6:09pm

chemistry
How do I do a limiting reactant equation? The questions my teacher gave me are confusing and nothing we ever learned in class.
Sunday, February 17, 2013 at 5:50pm

Chemistry
Determine the direction of the following reaction from the relative strengths of acids and bases: H2S(aq) + C2H3O2-(aq) yields Hc2H3O2(aq) + HS-(aq) The book says this will favor the reactants. I'm confused...shouldn't this be neutral because both reactants and ...
Sunday, February 17, 2013 at 5:07pm

Chemistry
What mass of precipitate will form if 1.50 L of concentrated Pb(ClO3)2 is mixed with 0.750 L of 0.170 M NaI? Assume the reaction goes to completion.
Sunday, February 17, 2013 at 4:52pm

Chemistry
Is this right?: Energy is absorbed in order to break bonds because bond breaking requires energy. Or are these two statements completely separate?: "energy is absorbed when bonds break" and "breaking bonds require energy"
Sunday, February 17, 2013 at 4:30pm

maths
1) A chemistry teacher requires 250 milligrams of a chemical for an experiment. He has 30 grams of the chemical. How many times can he carry out the experiment? 2) A bottle contains 1.5 litres of cola. Hannah drinks 300 ml of the cola and Ben drinks 450 ml.How much of the cola...
Sunday, February 17, 2013 at 2:57pm

Chemistry
At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.100 M and [NO]=0.400 M. N2 (g) + O2 (g) --> 2NO (g) If more NO is added, bringing its concentration to 0.700 M, what will the final concentration of NO be after equilibrium is re-established?
Sunday, February 17, 2013 at 2:49pm

chemistry
25ml of a solution of na2c03 having a specific gravity of 1.25g ml required 32.9ml of a solution of hcl containing 109.5g of the acid per litre for complete neutralization. Calculate the volume of 0.84N heso4 that will be compltetly neutralized by 125g of na2c03 solution The ...
Sunday, February 17, 2013 at 12:45pm

chemistry
under what condition del(h) becomes del(u)
Sunday, February 17, 2013 at 10:20am

chemistry
what is real gas ?
Sunday, February 17, 2013 at 10:17am

chemistry
Effect of temperature on surface tension an viscosity ?
Sunday, February 17, 2013 at 10:12am

Chemistry
58% Ca3 (PO4) 2 how many phosphorus are in 10 kg bones? Ca3(po4)2+SiO2+C=CaSiO3+P4
Sunday, February 17, 2013 at 10:09am

chemistry
what is molality ?
Sunday, February 17, 2013 at 9:54am

chemistry
what is molality ?
Sunday, February 17, 2013 at 9:52am

Chemistry
Explain why a mixture formed by mixing 100 mL of 0.1 M acetic acid and 50 mL of 0.1 M sodium hydroxide will act as buffer
Sunday, February 17, 2013 at 6:45am

Chemistry
Cyclopropane rearranges to form propene: CH2CH2CH2 --> CH2=CHCH3 by first-order kinetics. The rate constant is k = 2.74 x 10-3 s-1. The initial concentration of cyclopropane is 0.290 M. What will be the concentration of cyclopropane after 100 seconds?
Sunday, February 17, 2013 at 5:01am

Chemistry
The decomposition of N2O5(g) --> NO2(g) + NO3(g) proceeds as a first order reaction with a half-life of 30.0 seconds at a certain temperature. If the initial concentration [N2O5]0 = 0.400 M, what is the concentration after 120 seconds?
Sunday, February 17, 2013 at 5:00am

Chemistry
2A + B2 + C --> A2B + BC Run # Initial Rate (M-1s-1) (A)o (B)o (C)o 1 1.6 x 106 1.2 M 1. x 10-2 M 1.0 M 2 1.6 x 106 2.4 M 1. x 10-2 M 1.0 M 3 3.2 x 106 1.2 M 2. x 10-2 M 1.0 M 4 6.4 x 106 1.2 M 1. x 10-2 M 2.0 M What would be the rate-law expression of the reaction above?
Sunday, February 17, 2013 at 4:55am

chemistry
Pt, (H2) 1atm | CH3COOH 0.1 M, CH3COONa 0.15M || NaBr 0.1M, AgBr(S) | Ag write the cathodic, anodic and final reactions.
Sunday, February 17, 2013 at 4:51am

chemistry 11
what conclusion can you make from the ratio of moles of copper to moles of iron in this reaction fe+cucl2---> fecl2+ cu
Sunday, February 17, 2013 at 3:30am

chemistry
A solution contains 0.02755 g of a protein in 25.0 mL of solution. The osmotic pressure is 3.22 torr at 298 K. What is the molecular weight of the protein?
Sunday, February 17, 2013 at 2:07am

Chemistry
Lauryl alcohol is obtained from coconut oil and is used to make detergents. A solution of 5.00 g of lauryl alcohol in 100.0 g of benzene freezes at 4.2 oC. What is the approximate molar mass of lauryl alcohol. Refer to the text book for the boiling point of pure benzene. (80 C...
Sunday, February 17, 2013 at 2:06am

Chemistry
Given a very concentrated glycercol solution. Dilute it to 7.5 fold dilution. How do I do this ?
Sunday, February 17, 2013 at 1:22am

Chemistry
The formula for rust can be represented by Fe2O3. How many moles of Fe are present in 21.3g of the compound? Please help. I am SO confused on all of this!!
Saturday, February 16, 2013 at 9:54pm

Chemistry
What volume of a 0.22mol/L hydrochloric acid solution is needed to cause the pH of 25.00mL of a 0.15mol/L lithium hydroxide solution to have a pH that s equal to 7.00
Saturday, February 16, 2013 at 9:42pm

chemistry
25ml of a solution of na2c03 having a specific gravity of 1.25g ml required 32.9ml of a solution of hcl containing 109.5g of the acid per litre for complete neutralization. Calculate the volume of 0.84N Hes04 that will be completely neutralized by 125g of nac03 solution The ...
Saturday, February 16, 2013 at 9:15pm

Chemistry
Had a recent mix-up when I re-read my chemistry notes, and trying to clear things up properly; is this right?: When bonds form, energy is released, and so the reaction absorbs energy. I have two different things written... a bond breaking results in energy absorption, breaking...
Saturday, February 16, 2013 at 7:38pm

chemistry
Assume that Kc = 0.0360 at 520°C for the first reaction above. What is the Kc for the second reaction at the same temperature? 2 HI(g)-> H2(g) + I2(g) H2(g) + I2(g) -> 2 HI(g) I thought the answer woudl just be negative because all you have to do is switch the ...
Saturday, February 16, 2013 at 6:58pm

Chemistry
You use 2.80 g of NaHCO3, and determined that 2.83 g of carbon dioxide ar produced. Convert the mass of NaHCO3 to moles: Convert the mass of CO2 to moles:
Saturday, February 16, 2013 at 5:45pm

Chemistry
Some of your reaction mixture splashed out of the beaker when you dropped the tablets into the acetic acid. How would this affect your measurements? Woud your final calculated mass of sodium bicarbonate in the tablet be artificially high or low as a result of this splashing?
Saturday, February 16, 2013 at 5:39pm

Chemistry
Calculate the molality, molarity, and mole fraction of FeCl3 in a 39.2 mass % aqueous solution (d = 1.238 g/mL).
Saturday, February 16, 2013 at 5:07pm

Chemistry
A biochemical engineer isolates a bacterial gene fragment and dissolves a 11.8 mg sample of the material in enough water to make 36.1 mL of solution. The osmotic pressure of the solution is 0.340 torr at 25°C. (a) What is the molar mass of the gene fragment?(in g/mol) (b) ...
Saturday, February 16, 2013 at 4:55pm

Chemistry
Calculate the vapor pressure of a solution of 0.48 mol of cholesterol in 6.0 mol of toluene at 32°C. Pure toluene has a vapor pressure of 41 torr at 32°C. (Assume ideal behavior.)
Saturday, February 16, 2013 at 4:54pm

CHEMISTRY
The solubility of a compound in water is 6.8g/100ml at 0.33g/100ml at 25 degree celsius. Calculate the amount of water required to crystallise 10g of the compound. If the pure compound is collected at 25 degree celsius, what is the maximum possible yield percent?
Saturday, February 16, 2013 at 3:47pm

chemistry
If 125cal of heat is applied to a 60.0-g piece of copper at 20.0(Deg C), what will the final temperature be? The specific heat of copper is 0.0920cal/(g.degC)
Saturday, February 16, 2013 at 2:26pm

Chemistry
A compound of Tin Sulfate is decomposed in the lab to give 1.91g of Tin, 1.03 grams of Sulfur, and 2.06g Oxygen. Determine if this is a compound of Tin(II) Sulfate or Tin(IV) Sulfate.
Saturday, February 16, 2013 at 1:12pm

chemistry
Please help me with this dilution. Given a very concentrated tube of virus. Apply serial dilution to make 1:7500 dilution. Dilute virus in PBS
Saturday, February 16, 2013 at 10:26am

chemistry
In terms of kinetic theory explain why tyre should not be over inflated
Saturday, February 16, 2013 at 5:11am

chemistry
A compound with the percent composition shown below has a molar mass of 60.10g/mol. Find its molecular formula: C, 39.97% H, 13.41% N, 46.62%
Friday, February 15, 2013 at 9:11pm

Chemistry
What is the final temperature after a 11.9 g piece of ice is placed into a Styrofoam cup containing 110 g of hot water at 73.3 degrees Celsius?
Friday, February 15, 2013 at 8:38pm

chemistry
do not understand this problem The Ksp of CaSO4 is 4.93× 10–5. Calculate the solubility (in g/L) of CaSO4(s) in 0.500 M Na2SO4(aq) at 25 °C.
Friday, February 15, 2013 at 7:23pm

Chemistry
I need to find the boiling point, but I am confused on this question 0.250M glucose in water (assume the density of water is 1.00 g/ml)
Friday, February 15, 2013 at 6:44pm

Chemistry
Arrange the following aqueous solutions in order of increasing boiling point, explain your answer: 0.120 m glucose (C6H12O6), 0.05 m LiBr, 0.05 m Zn(NO3)2. Using data the boiling point constants given in the test book, calculate the boiling points of each of the above aqueous ...
Friday, February 15, 2013 at 5:42pm

Chemistry
What is the % mass of 12 M hydrochloric acid. Density of 12 M hydrochloric acid solution is 1.18 g/mL and the density of water is 1.00 g/mL
Friday, February 15, 2013 at 5:42pm

Chemistry
How many grams of sulfuric acid is in 25.0 g of 8.00 % H2SO4 solution?
Friday, February 15, 2013 at 5:41pm

Chemistry
How many moles of Sulfur are in 1 mole of Al2(SO4)3 and If the densitry of a noble gas is 1.783 g/L at STP, that gas is.... My guess: Argon? Then theres a question that says "Which as the greater mole.... and it lists things like: 1 mole Of Ar 1 Mole of O How would you ...
Friday, February 15, 2013 at 2:36pm

Chemistry
Currently studying for an lab exam. Just have a few question about a typical Iodine Clock reaction lab. In an typical Iodine Clock reaction lab what would be the state of effect of an increase in the initial concentration of thiosulfate ion (S2O3 2-) and the increase in the ...
Friday, February 15, 2013 at 12:52pm

Chemistry
Currently studying for an lab exam. Just have a few question about a typical Iodine Clock reaction lab. In an typical Iodine Clock reaction lab what would be the state of effect of an increase in the initial concentration of persulfate ion (S2O3 2-) and the increase in the ...
Friday, February 15, 2013 at 12:47pm

chemistry
To 160.0 mL of a buffer solution containing 0.250 M ammonia and 0.100 M ammonium chloride, 20.00 mL of 1.00M HClO4 are added. a) Calculate the pH of the new solution. b) What becomes the pH if another 20.00 mL of the same acid solution is added?
Friday, February 15, 2013 at 10:49am

Chemistry
A solution contains 314 mg/L of Ca2 . What is the solution in nmol/m3?
Friday, February 15, 2013 at 12:40am

Chemistry
What are the units for rate constant? I know each may have different units for the k value, I just don't know how to get them. How can I tell just by looking at a given rate law?
Friday, February 15, 2013 at 12:34am

chemistry
!. Which of the following structures would you expect to have a net dipole moment? HC(triple bond)CH NH4+ H2C(double bond)O BCl3 2. Rank the sp, sp2, and sp3 orbitals in order of decreasing (highest to lowest) energy. a)sp> sp2>sp3 b)sp3>sp2>sp c)sp2>sp>sp3 d...
Friday, February 15, 2013 at 12:10am

chemistry Emergency TEST
1.How many moles of sodium oxide are produced when3.9 moles of sodium combine with excess oxygen. 2. Sodium chloride decomposes into elemental sodium and elemental chlorine.How many grams of chlorine will be produced if 39.4 grams of sodium chloride decomposes 3.If 6.7 moles ...
Thursday, February 14, 2013 at 10:50pm

Chemistry
You weigh out 1.20 g of sodium carbonate monohydrate, dissolve it in water and react it with 15.00 mL of 2.00 M HCl. Write an equation for the reaction and calculate the expected mass of carbon dioxide that will be produced.
Thursday, February 14, 2013 at 10:32pm

chemistry
A 3.24-L flask is filled with propane gas (C3H8), at 1.00 atm and -13.5°C. What is the mass of the propane in the flask?
Thursday, February 14, 2013 at 9:48pm

analytical chemistry
Write balanced net-ionic equations to describe: a. The oxidation of Mn2+ to MnO4- by ammonium peroxydisulfate [(NH4)2S2O8] b. The air-oxidation of HAsO32- to HAsO42- c. The oxidation of Ce3+ to Ce4+ by sodium bismuthate (NaBiO3) Write balanced net-ionic equations to describe: ...
Thursday, February 14, 2013 at 8:27pm

Chemistry
find the heat energy needed to change 200 g of water at 4c to water at 88c
Thursday, February 14, 2013 at 4:06pm

chemistry
find the heat energy needed to change 150g of ice at -15c to ice at -63c
Thursday, February 14, 2013 at 4:03pm

Chemistry
A solvent has a molar mass of 37.2 g/mol and a normal boiling point of 111.2 oC. The boiling point elevation constant, K b , for this solvent is 1.58 oC/m. If 18.7 g of a nonelectrolyte having a molar mass of 20.5 g/mol are mixed with 170.0 g of the solvent, what is the ...
Thursday, February 14, 2013 at 3:35pm

chemistry
A saturated solution of NaCl (dissolved in water) has a concentration of 4.01 M at a given temperature. The solution has a volume of 1 L (1000 mL). If the water were to evaporate until the volume of the solution is 500 mL (and then stirred), what would the concentration of ...
Thursday, February 14, 2013 at 3:34pm

Chemistry
How much acid is needed to neutralize a 5L solution with a pH of 12.5. The acid available is 1 N HCL.
Thursday, February 14, 2013 at 1:56pm

chemistry
A 230 g sample of a compound contains 136.6 g of carbon, 26.4 g of hydrogen, and 31.8 g of nitrogen. The rest is oxygen. What is the mass percent of oxygen in the compound?
Thursday, February 14, 2013 at 11:01am

chemistry
h2s + HNO3 -->s+ no+H2O balance by oxidation number change
Thursday, February 14, 2013 at 10:21am

chemistry
How many moles of water will produced at equilibrium be if there is 1.0 mole of carbon dioxide formed at equilibrium?
Thursday, February 14, 2013 at 8:50am

chemistry
why cant Na be used to prepare H2?
Thursday, February 14, 2013 at 7:45am

chemistry
The concentration of a certain ionic compound in aqueous solution is 0.186mol/L . It is only solute in the solution. The concentration of pottassium ions in the same solution ia 0.558mol/L. Explain why the concentrations of the ions in the solution are different. What might ...
Thursday, February 14, 2013 at 6:19am

Chemistry
1) Aldrin and dieldrin are pesticides that used to be allowed for the control of soil insects. In ontario, the maximum allowable total concentration of alrin plus dieldrin in drinking water is 0.7 ppb. If a 250mL sample of drinking water is found to contain 0.0001mg of aldrin ...
Thursday, February 14, 2013 at 6:06am

CHEMISTRY
Ni(NO3)2.H2O+2KSCN WHAT IS THE PRODUCT?? WHAT COMPLEX IS FORMED ?
Thursday, February 14, 2013 at 5:22am

Fundamentals of Chemistry
balance the equation by ion electron method. Fe^++ + MnO4- = Fe3+ +Mn2+ (acidic medium) please help me..!!
Thursday, February 14, 2013 at 3:43am

chemistry
Exactly 50.0ml solution of Na2CO3 was titrated with 65.8ml of 3.00M HCl. If the specific gravity of the Na2CO3 solution is 1.25, what percent by weight of Na2CO3 does it contain?
Thursday, February 14, 2013 at 3:19am

Chemistry
Need help on a lab results write-up. The lab is the synthesis and analysis of a transition metal complex. General reaction was stated as: Fe(III) + x(acac) -> Fe(acac)x - we were to determine x by completing experiment. x = 1, 2, 3, 4... acac = 2, 4 pentanedione Procedure ...
Thursday, February 14, 2013 at 12:14am

Chemistry
Given the following equilibrium constants are given at 377°C, 1/2 N2(g) + 1/2 O2(g) NO(g) K1 = 110−17 1/2 N2(g) + O2(g) NO2(g) K2 = 110−11 N2(g) + 3/2 O2(g) N2O3(g) K3 = 210−33 N2(g) + 2 O2(g) N2O4(g) K4 = 410−17 determine the values for the ...
Wednesday, February 13, 2013 at 11:49pm

Chemistry
At a particular temperature, 13.7 mol of SO3 is placed into a 3.9-L rigid container, and the SO3 dissociates by the reaction given below. 2 SO3(g) 2 SO2(g) + O2(g) At equilibrium, 3.8 mol of SO2 is present. Calculate K for this reaction.
Wednesday, February 13, 2013 at 11:08pm

Chemistry
I am doing a lab on enthaply of vaporization of water, I got everything else on the post lab but these two questions, please help. The deltaHvap data from the handbook reference vary with temp. 1) if your data were perfect, but deltaHvap is not constant, how would this show up...
Wednesday, February 13, 2013 at 10:10pm

Chemistry
How many grams of HCl need to be dissolved in 0.5L of water to prepare a solution of pH 1.5? Does anybody know how to work this out? Thanks :)
Wednesday, February 13, 2013 at 9:07pm

chemistry
A crucible containing potassium chlorate has a mass is 24.426 g. The crucible is heated according to the lab procedure for this week's experiment and is found to weigh 23.202 g. Write an equation for the reaction and, assuming that all the chlorate decomposed, calculate ...
Wednesday, February 13, 2013 at 8:45pm

chemistry
You weigh out 1.70 g of sodium carbonate monohydrate, dissolve it in water and react it with 15.00 mL of 2.00 M HCl. Write an equation for the reaction and calculate the expected mass of carbon dioxide that will be produced.
Wednesday, February 13, 2013 at 7:53pm

Chemistry
A sample of gaseous PCl5 was introduced into an evacuated flask so that the pressure of pure PCl5 would be 0.54 atm at 425 K. However, PCl5 decomposes to gaseous PCl3 and Cl2, and the actual pressure in the flask was found to be 0.85 atm. Calculate Kp for the decomposition ...
Wednesday, February 13, 2013 at 7:09pm

chemistry
2.0 x 10^-5 grams of hydrogen gas at 155 degree calsius exert a pressure of 322.5 torr on the walls of a small cylindrical tube. What is the volume of the tube?
Wednesday, February 13, 2013 at 6:48pm

chemistry
To what temperature, in degree celsius, must 10.0 grams of ammonia gas (NH3) have to be heated in a 15.0 L container in order for it to exert a pressure of 3.50 atm?
Wednesday, February 13, 2013 at 6:46pm

Chemistry
Burning an empty Styrofoam container results in volumes of black sooty flames. On the basis of this observation alone, to what class of hydrocarbons would you suspect a component of the polystyrene polymer found in Styrofoam belongs? Explain.
Wednesday, February 13, 2013 at 6:41pm

chemistry
Calculate the molecular weight of a gas if 4.5L of the gas at 785 torrs and 23.5 degrees celcius weigh 13.5g.
Wednesday, February 13, 2013 at 6:28pm

Chemistry
I did a lab today in class and part of the lab is to experimentally find the enthalpy for the dissolution of ammonium chloride by dissolving 4.0 g of NH4Cl(s) in 50.0 mL of H2O(l). I got a -5°C temperature change and calculated delta H to be 15 kJ/mol. According to the ...
Wednesday, February 13, 2013 at 5:41pm

chemistry
NH4HS(s) <-> NH3(g) + H2S(g) An equilibrium mixture of this reaction at a certain temperature was found to have (NH3)=.268 and (H2S)=.360 What is the value of the equilibrium constant at this temperature?
Wednesday, February 13, 2013 at 5:29pm

CHEMISTRY
Help Please!!!! H2SO4(aq) = 2H+(aq) + SO42-(aq) What is the hydrogen ion concentration, in mol dm−3, when 1.50 g of sulfuric acid is dissolved in water to give 0.500 dm3 of solution
Wednesday, February 13, 2013 at 5:19pm

college chemistry 101
why does an opened bottle of carbonated water keep its frizz longer if kept in a refrigerator than if left at room temperature?
Wednesday, February 13, 2013 at 4:03pm

Chemistry
The solubility of nitrogen in water is 6.9 x 10^-4 at exactly 1 atm pressure. What is the solubility of nitrogen under .80 atmp pressure? I don't know where to start with this problem, what formula do I use?
Wednesday, February 13, 2013 at 3:38pm

Chemistry
The freezing point of ethanol is -114.6 C and its Kf value is 2.00 C/m. What is the freezing point for the solution prepared by dissolving 50.0 g of glycerin (C3H8O3) in 200.0 g ethanol? I used Change in temp=Kfm kf=2.00 I calculated m to be 2.1736. I ended up the answer of -...
Wednesday, February 13, 2013 at 3:34pm

chemistry
what are the fundamental particles in antifreeze
Wednesday, February 13, 2013 at 3:14pm

chemistry
what determines the color of light when an electron moves from one level to another
Wednesday, February 13, 2013 at 3:07pm

chemistry
What volume of a 6.0 M NaOH solution would you need to prepare 250.0 milliliters of a 3.0 M NaOH solution?
Wednesday, February 13, 2013 at 2:40pm

Chemistry
How many milliliters of water has been dispensed if the initial buret reading was 0.38 ml and the final is 24.70 ml
Wednesday, February 13, 2013 at 1:24pm

chemistry
why we cant use hcl to react with Fe to create fecl3?
Wednesday, February 13, 2013 at 1:06pm

Chemistry
What is the osmotic pressure of .100 M solution of aluminum chloride at 27 deg C? I used the formula: pi=(i)(M)(R)(T) wasn't sure what i was but for M put down 0.100M, R=0.08206 and T=300K Answer is 9.85, but not sure how to get that.
Wednesday, February 13, 2013 at 11:59am

Chemistry
The freezing point of ethanol is -114.6 deg Celsius and its Kf value is 2.00degC/m. What is the freezing point for a solution prepared by dissolving 50.0g of glycerin in 200g ethanol? I thought it may have been using the formula deltaT=Kf*m, but I'm not sure.
Wednesday, February 13, 2013 at 11:51am

Chemistry
How many moles of Al(OH) are required to completely react with 2.75mol of H2SO4?
Wednesday, February 13, 2013 at 10:46am

chemistry
determine ox number of each atom below A. CF4 B. KO2 C. SnO D. H2SO4 E. Fe2S3 F. AuCl3
Wednesday, February 13, 2013 at 10:05am

chemistry
Balance using oxidation Number Methode A. MnO4- + C2H4 + H20 --> MnO2 + OH- + C2H6 B. ClO- --> Cl- + ClO3-
Wednesday, February 13, 2013 at 10:03am

chemistry
Balance using oxidation Number Methode A. MnO4- + C2H4 + H20 --> MnO2 + OH- + C2H6 B. ClO- --> Cl- +
Wednesday, February 13, 2013 at 10:01am

chemistry
balance these redox reactants & determine oxidator agent and reducing agent A. Zn + NO3- --> Zn+2 +NH4 + Acid B. Cr(OH)3 + H2O2 --> CrO4 -2 + H20 (Basic)
Wednesday, February 13, 2013 at 9:58am

chemistry
In raction NH3 + 5 O2 --> 4 NO + 6 H20 . I 1 mol NH3 and 1 mol O2. what is the limiting reactant? ow Much NO will form?
Wednesday, February 13, 2013 at 9:54am

chemistry
a sample of iron are is known as Fe3O4. A 50 gram of sample contain 26 gram of Fe. Determine % yield Fe3O4 In sample
Wednesday, February 13, 2013 at 9:51am

chemistry
in reaction = Mg + O2 --> MgO if 24 gram of Mg is burned in excess oxygen to form 40 gram of MgO, How much O2 is used?
Wednesday, February 13, 2013 at 9:49am

chemistry
in reaction S + O2 -> SO2, determine percent yield if 4 grams of S produced 64 gram of SO2
Wednesday, February 13, 2013 at 9:47am

chemistry
in reaction S + O2 -> SO2, determine percent yield if 4 grams of S produced 64 gram of SO2
Wednesday, February 13, 2013 at 9:43am

chemistry
anyone help me . .what volume of concentrated HCL solution whoch is 36% by mass and has a density of 1.179 g/ml , should be used to make 4.7 L of hcl solution with a pH of 1.8 ?
Wednesday, February 13, 2013 at 8:30am

Chemistry
Chromatography relies on the differences in polarity between the compound, the mobile phase and the stationary phase. In your own words explain how polar and non-polar compounds can be separated using cellulose paper and petroleum ether. I have no idea
Wednesday, February 13, 2013 at 7:15am

chemistry
Sulfuric acid is a strong acid and dissociates in water as shown in Reaction 4. Equation label: (4) Help Please!!!! H2SO4(aq) = 2H+(aq) + SO42-(aq) What is the hydrogen ion concentration, in mol dm−3, when 1.50 g of sulfuric acid is dissolved in water to give 0.500 dm3 ...
Wednesday, February 13, 2013 at 7:04am

chemistry
in an attempt to establish the formula of an oxide of nitrogen , a known volume of the pure gas was mixed with hydrogen and passed over a catalyst at a suitable temperature. 100% conversion of the oxide to ammonia and water was shown to have taken place. NxHy gives xNH3 + YH20...
Wednesday, February 13, 2013 at 5:09am

Chemistry
You are asked to prepare a pH = 4.00 buffer starting from 1.50 L of 0.0200 M solution of benzoic acid (C6H5COOH) and some added sodium benzoate salt (C6H5COONa). a) Find the pH of the benzoic acid solution BEFORE adding the salt. b) Use the Henderson-Hasselbalck equation to ...
Wednesday, February 13, 2013 at 12:47am

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