Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
Mixtures of helium and oxygen are used in scuba diving tanks to help prevent ‘the bends’, a condition caused by nitrogen bubbles forming in the bloodstream. If 95 L of oxygen and 25 L of helium at STP are pumped into a scuba tank with a volume of 8.0 L, what is the ...
Wednesday, March 20, 2013 at 8:30am

Chemistry
How many grams of C6H12O6 must be added to 0.750 kg of water to make a 1.25 m solution?
Wednesday, March 20, 2013 at 1:56am

Chemistry
How many grams of H2SO4 are needed to make a 4.50 m solution in 300 g H2O?
Wednesday, March 20, 2013 at 1:53am

Chemistry
Repost:: sorry couldn't understand it What is the concentration of C2O4^-2 in a 0.370M oxalic acid solution? Ka1=5.6x10^-2 and Ka2=5.1x10^-5
Wednesday, March 20, 2013 at 12:48am

Chemistry
A solution of aniline(C6H5NH2, Kb=4.2x10^-10) has a pH of 8.69 at 25 Celsius. What was the initial concentration of aniline? I have so far don't know if it's right: *. [H3O]=10^-8.69=2x10^-9 * 4.2x10^-10=(2x10^-9)^2 / x X=1.2x10^-8 (correct???)
Wednesday, March 20, 2013 at 12:44am

chemistry
why wouldn't a higher experimental ratio of HCl increase the reaction rate for synthesis of t-pentyl alcohol?
Wednesday, March 20, 2013 at 12:42am

CHEMISTRY
1. What is the vapor pressure at 25°C of a solution of 1.20g of nephtalene C10H8 in 25.6g of benzone C6H6? The vapor pressure of pure benzene at 23°C is 86.0mmHg the vapor pressure of naphthalene can be neglected. Calculate the vapor pressure lowering of the solution. ...
Wednesday, March 20, 2013 at 12:14am

Chemistry
Chemical analysis of a germanium crystal reveals indium at a level of 0.0003091 atomic percent. Assuming that the concentration of thermally excited charge carriers from the Ge matrix is negligible, what is the density of free charge carriers (free carriers/cm3) in this Ge ...
Tuesday, March 19, 2013 at 11:46pm

chemistry
Which material would you expect to have a greater bandgap energy between indium nitride (InN) and indium phosphide (InP)?
Tuesday, March 19, 2013 at 11:42pm

Chemistry
1) What is the vapor pressure at 25°C of a solution of 1.20g ofnephtalene C10H8 in 25.6g of benzone C6H6? The vapor pressure of pure benzene at 23°C is 86.0mmHg the vapor pressure of naphthalene can be neglected. Calculate the vapor pressure lowering of the solution. 2...
Tuesday, March 19, 2013 at 11:30pm

Chemistry
59.0 mL of a 1.80 M solution is diluted to a total volume of 268 mL. A 134-mL portion of that solution is diluted by adding 171 mL of water. What is the final concentration? Assume the volumes are additive.
Tuesday, March 19, 2013 at 9:49pm

chemistry
if the molar mass of BaCl2 is 208.3 g/mol, how many grams are present in 0.25 moles?
Tuesday, March 19, 2013 at 9:44pm

college chemistry
for my lab i used 2.0mL of NaOH solution and it doesnt have a density in (g/mL)... is there still a way to calculate the moles to it? unless there is a density to NaOH
Tuesday, March 19, 2013 at 9:33pm

Chemistry
How many milliliters of 11.5 M HCl(aq) are needed to prepare 310.0 mL of 1.00 M HCl(aq)?
Tuesday, March 19, 2013 at 9:21pm

chemistry
How many moles of hno3 neede to prepare 7.5 l of a 5.6m solution
Tuesday, March 19, 2013 at 9:13pm

Chemistry
Assume you started with a 0.642 gram sample of Sodium Bicarbonate and aster adding an excess of hydrochloric acid and carrying out the experiment correctly, you calculateed there was a 94.8% yield of sodium chloride. What was the experimental yield of sodium chloride in the ...
Tuesday, March 19, 2013 at 9:12pm

Chemistry
How do you write a chemical equation for NH4NO3? Is it... NH3 + H2O= NH4 + OH
Tuesday, March 19, 2013 at 9:10pm

Chemistry
A 30.0-ml sample of 0.165 M propanoic acid is titrated with 0.300 M KOH. What is the pH at 5 ml of added base, at 10 ml of added base?
Tuesday, March 19, 2013 at 8:22pm

Chemistry
A coffee cup calorimeter contains 25.0 grams water at 23.8 C A 5.00g sample of an unknown metal at an initial temperature of 78.3 C was dropped into the calorimeter. The final temperature of mixture was 46.3 C. Calculate the specific heat of the metal. The specific heat of ...
Tuesday, March 19, 2013 at 8:14pm

Chemistry
What is the enthalpy for the following reaction? N204 = 2NO + O2
Tuesday, March 19, 2013 at 8:14pm

Chemistry
What is the concentration of C2O4^-2 in a 0.370M oxalic acid solution? Ka1=5.6x10^-2 and Ka2=5.1x10^-5
Tuesday, March 19, 2013 at 8:10pm

Chemistry
What is the hydroxide ion concentration of a 0.370M oxalic acid, H2C2O4, solution? For oxalic acid, Ka1=5.6x10^-2 and Ka2=5.1x10^-5
Tuesday, March 19, 2013 at 8:08pm

Chemistry
What is the concentration of CO3^-2 in a 0.028M solution of carbonic acid, H2CO3? For carbonic acid, Ka1=4.2x10^-7 and Ka2=4.8x10^-11
Tuesday, March 19, 2013 at 8:05pm

Chemistry
What is the hydronium ion concentration in a 0.010M solution of carbonic acid, H2CO3? For carbonic acid, Ka1=4.2x10^-7 and Ka2=4.8x10^-11.
Tuesday, March 19, 2013 at 8:00pm

Chemistry
The Keq for the equilibrium below is 5.4 × 1013 at 480.0 °C. 2NO (g) + O2 (g) ↔ 2NO2 (g) What is the value of Keq at this temperature for the following reaction? NO2 (g) ↔ NO (g) + 1/2 O2 (g) The Keq for the equilibrium below is 5.4 × 1013 at 480.0...
Tuesday, March 19, 2013 at 7:26pm

Chemistry
Which solution below has the highest concentration of hydronium ions? pH = 9.82 pH = 12.6 pH = 7.93 pH = 3.21 pH = 7.00
Tuesday, March 19, 2013 at 7:26pm

Chemistry
You have a stock 0.100 M solution of KMnO4 and a series of 100-mL volumetric flasks. What volumes of the stock solution will you have to pipet into the flasks to prepare standards of 1.00, 2.00, 5.00, and 10.0x10^-3M KMnO4 solutions? I tried using M1V1=M2V2 but the answers ...
Tuesday, March 19, 2013 at 7:22pm

Chemistry
What weights of NaH2PO4 and NaHPO4 would be required to prepare a buffer solution of pH 7.45 that has an ionic strength of 0.1? pKa2=7.12 , mwt NaH2Po4=120g/mol NaHPO4=142 g/mol using the henderson-hasselbalch equation i got that the ratio of the concentration of NaH2PO4 to ...
Tuesday, March 19, 2013 at 7:20pm

Chemistry
A scuba diver takes a 2.3 balloon from the surface, where the pressure is 1.1 and the temperature is 28, to a depth of 35 , where the pressure is 4.5 and the temperature is 14.
Tuesday, March 19, 2013 at 6:55pm

Chemistry 2 Lab
Calculate the degree of ionization of acetic acid in solution 1 through 3? All I am giving is the pH... pH of solution 1= 3 pH of solution 2= 3.5 pH of solution 3= 5 Then, I did this... HC2H3O2 (aq) + H2O (l) equals H3O+ (aq) + C2H3O2- (aq) Ka= 1.7 E -5 (according to chart in ...
Tuesday, March 19, 2013 at 6:50pm

chemistry
the enzyme that takes in the SO2−4 that provides the sulfur atom for cysteine.
Tuesday, March 19, 2013 at 5:55pm

chemistry
What is the percent by volume (% v/v) of a solution made by mixing 12 ml of ethanol (C2H5OH) with 48 ml of water? b) Assuming the density of ethanol is 0.789g/ml, what is the molarity of this solution?
Tuesday, March 19, 2013 at 4:52pm

chemistry
Acetic acid, CH3CO2H, is the active ingredient in vinegar. It's often abbreviated "HOAc". Vinegar is acidic because acetic acid makes H3O+ when it partially ionizes in water: HOAc(aq) + H2O H3O+(aq) + OAc–(aq) Suppose that you have a solution of acetic acid ...
Tuesday, March 19, 2013 at 4:50pm

Chemistry
In an experiment with a titration of Vitamin C with Iodine, why must the iodine dropper be standardized?
Tuesday, March 19, 2013 at 3:44pm

Chemistry
Calculate the pH of the 0.20 M NH3/0.25 M NH4Cl buffer. I calculated the pH to be 9.15 What is the pH of the buffer after the addition of 10.0 mL of 0.10 M HCl to 72.5 mL of the buffer?
Tuesday, March 19, 2013 at 3:14pm

Chemistry
A student completed the standardization procedure & found that the value for her dropper was 0.133 mg Vitamin C/dp l2. The student then selected a juice & titrated it with the iodine from the dropper bottle. The sample turned blue with the addition of the 19th drop. How many ...
Tuesday, March 19, 2013 at 3:03pm

Chemistry
During the standardization procedure of the iodine dropper, a student used 10.0 mL of a 1.00 mg.mL standard of Vitamin C. After adding 41 drops of iodine to the 10.0 mL of the standard, the sample was a deep blue. Calculate how many mg of Vitamin C are titrated by each drop of...
Tuesday, March 19, 2013 at 2:37pm

chemistry
Calculate whether or not a precipitate will form if 1.40 mL of 0.62 M NH3 are added to 4.4 L of 1.0 10-3 M FeSO4.
Tuesday, March 19, 2013 at 2:33pm

Chem
in a 0.01 M solution of 1.4 butanedicarboxylic acid, (Ka1=2.9x10^-5, Ka2=5.3x10^-6), which species is present in the lowest concentration?
Tuesday, March 19, 2013 at 2:15pm

Chemistry
Solution x has a pH of 4.35. Solution y has 10- times high [OH-] compared to solution x. Solution z has a pH 4.0 units higher than that of solution x. calculate the ration of [H3O+] between solutions x&y and between x&z. What is the pH of solutions y and z? classify each ...
Tuesday, March 19, 2013 at 2:12pm

chemistry
liquid water + liquid oil + water vapor how many phases does this system have? If it's 3 ... why can't we say it's 2 taking in consideration the liquid part and the vapor part "states of matter also called phases" ... Please try to explain this concept if...
Tuesday, March 19, 2013 at 2:02pm

Chemistry 104
What is the percent ionization of a solution prepared by dissolving 0.0286 mol of chloroacetic acid in 1.60 L of water? For chloroacetic acid ,Ka=1.4x10^-3
Tuesday, March 19, 2013 at 12:45pm

Chem
What is the equilibrium concentration of chloroacetic acid in a solution prepared by dissolving 0.0314 mil of chloroacetic acid in 1.10L of water? For chloroacetic acid, Ka= 1.4X10^-3
Tuesday, March 19, 2013 at 12:42pm

chemistry
How many moles of water are produced by the complete combustion of 14.4g of C5H12?
Tuesday, March 19, 2013 at 9:28am

chemistry
How many moles of sulfate ions are in 100 ml of a solution of .002 M Fe2(SO4)3?
Tuesday, March 19, 2013 at 9:18am

CHEMISTRY
NEED HELP (Combined gas Law) A gas at a pressure of 1.50 atm has a volume of 200 mL. Calculate the new volume if the pressue changes to 1.20 atm. Assume constant temperature.
Tuesday, March 19, 2013 at 9:16am

Chemistry
(Ideal Gas Law) Calculate the volume of a 0.25 mole sample of gas at 25.0 degreeC and a pressure of 1.50 atm (R= 0.0821)
Tuesday, March 19, 2013 at 8:57am

Chemistry
Need help with problem (Molarity) How many grams of NaOH are required to prepare 500.0mL of a 2.00 M solution?
Tuesday, March 19, 2013 at 8:47am

Chemistry
Molar Volume(1mole=24.4L at STP) Question: Convert 40mL to moles I converted 40mL to .04L *Need help in coverting .04L to moles
Tuesday, March 19, 2013 at 7:47am

Chemistry
Acetone has a delta Hvap of 29.1 kj/mol and a normal boiling point of 56.2 degrees Celsius. At what temperature (in degrees Celsius) does acetone have a Pvap = 118 mm Hg?
Tuesday, March 19, 2013 at 1:29am

chemistry
Based on the following reaction 2A + 3B --> A2B3, if 1 mole of A is reacted with 2 moles of B, explain how you would determine which of the two substances is the limiting reactant.
Tuesday, March 19, 2013 at 12:58am

Chem
Hypobromous acid,HOBr, has acid -ionization constant of 2.5 X 10^-9 at 25 Celsius . What is the pOH of a 0.63 M HOBr solution? A4.40 B3.87 C5.20 D9.60 E10.13 I'm getting two answers between A or B
Tuesday, March 19, 2013 at 12:18am

Chemistry
What is the pH of a 0.20 M HF solution that is 5.8% ionized at 25 Celsius ? A.4.45 b.0.70 C.1.93 D.1.23 E.1.40
Tuesday, March 19, 2013 at 12:02am

Chemistry
At a given Temperature, the elementary reaction A<--->B in the forward direction is first order in A with a rate constant of 3.90*10^-2s^-1. The reverse reaction is first order in B and the rate constant is 8.20*10^-2s^-1. What is the value at equillibrium for the ...
Monday, March 18, 2013 at 11:06pm

Chemistry
the hydronium ion concentration of a 0.050 M solution of a weak acid is 5.9 X 10^-3 M. the acid-dissociation constant is 1.37 X 10^-4 at 25 celsius. what is the pH of this solution? A. 0.077 B. 1.30 C. 2.23 D. 3.86 E. 5.13
Monday, March 18, 2013 at 11:01pm

Chemistry
A 8.5 x 10^-3 M solution of acetic acid is 4.6% ionized at 25 degree Celsius. in a 8.5 X 10^-4 M solution, the percentage of ionization would be? A.the same B.>4.6% C.<4.6% D.zero E.100%
Monday, March 18, 2013 at 10:06pm

Chemistry
An experiment shows a 144mL sample of gas has a mass of 0.173g at a pressure of 720mmHg at a temperature of 31 degrees celsius. what is the molar mass of the sample of gas?
Monday, March 18, 2013 at 9:44pm

chemistry
It was a very cold day -10 C. Victor went outside to pick up the morning newspaper. He quickly noticed the icicle that formed on the nearby flagpole. Curiosity got the best of him, and he decided to lick the ice on the flagpole. Instantly, Victor's tongue is attached to ...
Monday, March 18, 2013 at 8:54pm

Chemistry
A 20.0mL 0.3M HCl solution is titrated with 0.4M NaOH. What is the exact pH of the solution before titration? And what is the pH at the equivalence point?(are there any straightforward formulas to use on this kind of problem?)
Monday, March 18, 2013 at 8:27pm

chemistry
how many grams of Na2SO4 can be produced by the reaction of 250g of NaOH with sufficient H2SO4?
Monday, March 18, 2013 at 7:56pm

Chemistry
Calculate the molar concentration of uncomplexed Zn2+ (aq) in a solution that contains 0.22 mol of Zn(NH3)4 2+ per liter and 0.3109 M NH3 at equilibrium. Kf for Zn(NH3)4 2+ is 2.9 X 10^9 I started this way... (0.3109 + 4)2/0.22-x)= 2.9 X 10^9
Monday, March 18, 2013 at 7:49pm

AP Chemistry
What mass in grams of sodium hydroxide is produced if 20.0 g of sodium metal reacts with excess water according to the chemical equation? 2Na(s)+2H20(l)=2NaOH(aq)+Hs(g) How many moles of Ag can be produced if 350. g of Cu are reacted with excess AgNO3 according to the ...
Monday, March 18, 2013 at 6:51pm

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?
Monday, March 18, 2013 at 5:48pm

Chemistry
What is the molarity of a salt solution that is made from 31.0 grams of Ca3(P04)2 placed in a volumetric flask and filled to the 2 liter line with distilled water?
Monday, March 18, 2013 at 5:40pm

Chemistry
How many grams ammonium chloride and how many milliliters 3.0 M sodium hydroxide should be added to 200 ml of water and diluted to 500 ml to prepare a buffer of 9.50 with a salt concentration of 0.1 M? Ka=9.24
Monday, March 18, 2013 at 5:24pm

Chemistry
Calculate the pH at the equivalence point for the titration of 0.130M methalamine (CH3NH2) with 0.13M Hcl. The Kb of methyl amine is 5.0x10-4.
Monday, March 18, 2013 at 4:44pm

Chemistry
What is the mass of iron (g) produced from 227.4 of iron(III) oxide ?
Monday, March 18, 2013 at 3:21pm

Chemistry
why is it important that the equations be balanced when performing mass-mass stoichiometry problems?
Monday, March 18, 2013 at 3:21pm

Chemistry
How many chlorine atoms are contained in a 1.00 g sample of iron(III) chloride, FeCl3? Use the masses to two decimal places from the chart in the front of your text. Use the format 6.02E23 for 6.02 x 1023, or 6.02E-23 for 6.02 x 10-23,use two decimal places in your answer.
Monday, March 18, 2013 at 3:20pm

Chemistry
Question 9 Marks: 2 In the reaction: Zn + 2 HCl ZnCl2 + H2 An excess of Zn is reacted with 300.0 g of HCl. How many grams of H2 will be produced?
Monday, March 18, 2013 at 3:19pm

Chemistry
How many grams of zinc must react to give 13.0 grams of ZnO according to the balanced equation. 2 Zn(s) + O2(aq) --> 2 ZnO(s)
Monday, March 18, 2013 at 3:17pm

Chemistry
How many grams of silver nitrate must react to give 67.5 grams of Ag according to the balanced equation. Cu(s) + 2 AgNO3(aq) --> Cu(NO3)2(aq) + 2 Ag(s)
Monday, March 18, 2013 at 3:16pm

Chemistry
Question 2 Marks: 2 How many grams of oxygen gas must react to give 174.3 grams of ZnO according to the balanced equation. 2 Zn(s) + O2(aq) --> 2 ZnO(s)
Monday, March 18, 2013 at 3:15pm

organic chemistry
when i add methyl salicylate to aqueous sodium hydroxide, immediately a white solid forms... that is sodium salicylate is it?? Since it hasn't been heating under reflux yet.
Monday, March 18, 2013 at 3:08pm

chemistry
A student extracts 6.3 g of water when performing the following combustion: C2H8 + 4O2 --> 2 CO2 + 4H2O If the theoretical yield is 8.6, what is the percent yield?
Monday, March 18, 2013 at 3:06pm

chemistry
a 225.0 g sample of an unknown, silver, pure metal was heated to 95.5 degrees celsius then put into 150.50 g of water at 22.5 degrees celsius. the water was heated by the hot metal to a temperature of 31.4 degrees celsius. what is the specific heat? what is the metal?
Monday, March 18, 2013 at 2:59pm

Chemistry (reposting)
In which of the following solution would CaC2O4 have the highest molar solubility? Please help. A) 0.01 M NaCl B) 0.01 M H2C2O4 C) 0.01 M Na2C2O4 D) 0.01 M NaHC2O4 E) 0.01 M HCl I think it is E because it is a strong acid and will completely dissociate
Monday, March 18, 2013 at 12:42pm

Chemistry
A reaction mixture of 4.0 mL of 0.002 M SCN- and 5.0 mL of 0.002 M Fe3+ is diluted to 10.0 mL with 0.1 M HNO3 to form the blood-red FeNCS2+ complex. The equilibrium molar concentration of the FeNCS2+ determined from a standardization curve is 1.5x10^-4 mol/L. Calculate, in ...
Monday, March 18, 2013 at 11:48am

chemistry
define elements, compound and molecules.
Monday, March 18, 2013 at 11:07am

chemistry
5:8 emperical formula with hydrogen and carbon
Monday, March 18, 2013 at 8:26am

Chemistry
I could use some help please. Ammmonia, NH3, can be made by reacting Nitrogen with Hydrogen. N2+3H2=2NH3 How many moles of NH3 can be made if 7.5 moles of H2 react eith enough N2? Thank-you in advance for any help
Monday, March 18, 2013 at 7:28am

chemistry
Carbon reacts with chlorine and hydrogen to form the compound CH3Cl. (a) Construct the structure of CH3Cl. What is the dominant form of secondary bonding for CH3Cl? Dipole-dipole interactions, London dispersion forces, Covalent bonding, Ionic bonding
Monday, March 18, 2013 at 5:12am

chemistry
Which of the following combinations of atomic orbitals can combine to form sigma bonds? s-s ,s-p, p-p ,hybrid orbital - hybrid orbital ,hybrid orbital - s ,hybrid orbital - p
Monday, March 18, 2013 at 5:08am

chemistry
Rank the following 3 compounds in terms of increasing boiling point: CCl4, CH4, CH2Cl2 - Rank the following 3 compounds in terms of increasing boiling point: CF4, CH4, CH2F2 - Water, H2O, is a liquid at room temperature. Hydrogen selenide, H2Se, is a homologue compound. At ...
Monday, March 18, 2013 at 4:56am

chemistry
Construct the correct structure for AsClF42-. Please construct the molecule such that the dipole is oriented vertically up or vertically down. - Name the type of hybrid orbitals the central atom forms. - Name the molecular geometry of the compound. - State whether the molecule...
Monday, March 18, 2013 at 4:54am

Chemistry ....help
If NaNO3 is cooled from 70C to 10C ; how much solid NaNO3 will come out of solution as a solid salt? Help me !!!
Monday, March 18, 2013 at 2:08am

Chemistry
Solutions of sodium thiosulfate are used to dissolve unexposed AgBr (Ksp = 5.0 10-13) in the developing process for black-and-white film. What mass of AgBr can dissolve in 1.40 L of 0.425 M Na2S2O3? Ag+ reacts with S2O32- to form a complex ion. Ag+(aq) + 2 S2O32-(aq)--> Ag(...
Monday, March 18, 2013 at 12:32am

Chemistry
What is the pH of a saturated zinc hydroxide solution?
Monday, March 18, 2013 at 12:00am

Chemistry
Calculate the concentration of ions in the following saturated solutions. (a) [I −] in AgI solution with [Ag+] = 8.1 10-9 M (b) [Al3+] in Al(OH)3 solution with [OH −] = 1.8 10-9 M
Sunday, March 17, 2013 at 11:59pm

Chemistry
Sodium sulfate is slowly added to a solution containing 0.0500 M Ca^2+ (aq) and 0.0390 M Ag^+ (aq). What will be the concentration of Ca^2+ (aq) when Ag2SO4(s) begins to precipitate? What percentage of the Ca^2+ (aq) can be separated from the Ag^+ (aq) by selective ...
Sunday, March 17, 2013 at 10:49pm

chemistry
what is chromatography? Its history,purpose in chemistry.
Sunday, March 17, 2013 at 10:13pm

Chemistry...
Wha is PAV glue.? Full explanation please!
Sunday, March 17, 2013 at 10:01pm

Chemistry
At 22 °C an excess amount of a generic metal hydroxide M(OH)2, is mixed with pure water. The resulting equilibrium solution has a pH of 10.49. What is the Ksp of the salt at 22 °C? Is the ksp=1.38*10^-11?
Sunday, March 17, 2013 at 9:51pm

Chemistry
What concentration of SO32– is in equilibrium with Ag2SO3(s) and 3.20 × 10-3 M Ag ? The Ksp of Ag2SO3=1.50×10^–14 Is the concentration of SO32- = 4.69*10^-12?
Sunday, March 17, 2013 at 9:36pm

Chemistry
(Ksp= 5.0*10^-13) 1) Calculate the molar solubility of AgBr in 3.0×10^−2 M AgNO3 solution. 2) calculate the molar solubility of AgBr in 0.10 M NaBr solution. I tried solving using this the quadratic formula, but it didn't work. I started with these equations ...
Sunday, March 17, 2013 at 9:33pm

Chemistry
How many drops (1 drop=0.05mL) of 0.20M KI must we add to 100.0 mL of 0.010M Pb(NO3)2 to get a precipitate of lead iodide to start. Ksp of PbI2=7.1e-9. Answer=9 drops. Please show steps.
Sunday, March 17, 2013 at 9:29pm

Chemistry
At 25 °C only 0.0610 mol of the generic salt AB2 is soluble in 1.00 L of water. What is the Ksp of the salt at 25 °C? AB2(s) <- -> A^2+(aq)+2B^-(aq) Is the answer ksp=9.08*10^-4?
Sunday, March 17, 2013 at 9:20pm

chemistry
how many grams of KClO3 will dissolve in 1 liter of water at 50 degree celisus ?
Sunday, March 17, 2013 at 8:54pm

Chemistry
Is the dissolution of calcium sulfate endothermic or exothermic? How do you know?
Sunday, March 17, 2013 at 8:30pm

Chemistry
Suppose 50.00 mL of 2.0 E -5 M Fe(NO3)3 is added to 50.00ml of 2.0 E -4M KIO3. Which of the following statements is true? For Fe(IO3)3, Ksp= 1.0 E-14 a-precipate forms because Qc<Ksp b-No precipate forms because Qc>Ksp c-Nothing happended d-No precipate forms because Qc&...
Sunday, March 17, 2013 at 8:10pm

Chemistry
For the reaction: 2HCl + Na2CO3→ 2NaCl + H2O + CO2 how much CO2 is produced at STP if 18.5 L of 1.15 M Na2CO3is used? The molar mass of Na2CO3is 106.01 g/mol. I know I have to use stoichiometry and possibly PV=nRT but I don't know what to use first. Do I start with ...
Sunday, March 17, 2013 at 7:38pm

Chemistry
A .1M solution of chloroacetic acid is 11% ionized. Using this information, calculate [ClH2COO-], {H+], [ClCH2COOH] and Ka for cloroacetic acid.
Sunday, March 17, 2013 at 7:07pm

Chemistry
During your titration, you overshot your endpoint and your solution was too pink. Would this lead to a final pKa that was too high or too low? Explain why using chemical reasoning.
Sunday, March 17, 2013 at 6:24pm

Chemistry
What volume (L) of 0.256 M potassium hydroxide solution would just neutralize 61.3 ml of 0.167 M H2SO4 solution?
Sunday, March 17, 2013 at 5:38pm

CHEMISTRY
WHAT IS ATOMICRADIUS
Sunday, March 17, 2013 at 4:42pm

Chemistry
In which of the following solution would CaC2O4 have the highest molar solubility? Please help. A) 0.01 M NaCl B) 0.01 M H2C2O4 C) 0.01 M Na2C2O4 D) 0.01 M NaHC2O4 E) 0.01 M HCl I think it is E because it is a strong acid and will completely dissociate..
Sunday, March 17, 2013 at 4:17pm

Chemistry
2C2H6+7O2=4CO2+6H2O how many moles of H2O are produced when a mixture of 0.427 moles of O2 and 0.150 moles of C2H6 is burned, iv already found moles of H2O for them separately.
Sunday, March 17, 2013 at 3:21pm

Chemistry
What is the solubility (in g/L) of PbCl2 at 25 degree celsius? The solubility product of PbCl2 at 25 degrees celcius is 1.6x10-5.
Sunday, March 17, 2013 at 3:16pm

Gas Law problems ( Chemistry)
the initial temperature of a 1l sample of gas is 20c. The pressure is decreased from 720mmhg to 36mmhg and the volume increases to 2.14l. What was the final temperature of the gas?
Sunday, March 17, 2013 at 3:05pm

Chemistry
Write equations for the stepwise formation of each of the following complex ions. (Type your answer using the format CO2 for CO2, [NH4]+ for NH4+, and [Ni(CN)4]2- for Ni(CN)42-. Use the lowest possible coefficients.) (a) Ni(CN)42- (b) Mn(C2O4)22-
Sunday, March 17, 2013 at 2:50pm

Chemistry
What volume of a 15.0% by mass NaOH solution, which has a density of 1.116 g/mL, should be used to make 4.40 L of an NaOH solution with a pH of 10.5?
Sunday, March 17, 2013 at 1:58pm

College Chemistry/Lab Math
I think I have this problem figured out correctly, but is there anyone who can tell me if I'm doing something wrong. The question is... "One troy ounce of gold is worth $380. There are 33.8 grams per troy ounce. You have a stock colloidal solution of a very fine gold ...
Sunday, March 17, 2013 at 1:46pm

chemistry
If 24.0 L of O2 burns completely a sample of carbon disulfide, how many moles of sulfur dioxide (SO2) will be produced at 15 degrees Celsius at a pressure of 1.3 atm? CS2 + 3O2 -> CO2 + 2SO2
Sunday, March 17, 2013 at 1:13pm

chemistry
2) Suppose you have 5.00g of powdered magnesium metal, 1.00L of 2.00M potassium nitrate solution, and 1.00L of a 2.00M silver nitrate solution. a. Which one of the solutions will react with the magnesium powder?
Sunday, March 17, 2013 at 1:04pm

Chemistry
How do you solve this: if 24.0 L of O2 burns completely a sample of carbon disulfide, how many grams of sulfur dioxide will be produced at 15 degrees celcius at a pressure of 1.3 atm? (the answer is 45.7 g). CS2 + 3O2 -> CO2 + 2SO2
Sunday, March 17, 2013 at 12:45pm

chemistry
how do you use aldehydes to prepare acyl chlorides?
Sunday, March 17, 2013 at 12:45pm

Chemistry
if 24.0 L of O2 burns completely a sample of carbon disulfide, how many grams of sulfur dioxide will be produced at 15 degrees celcius at a pressure of 1.3 atm? CS2 + 3O2 -> CO2 + 2 SO2
Sunday, March 17, 2013 at 11:33am

chemistry
how do I calculate the mass of ammonium sulfate formed from the complete reaction of 700 grams of ammonia?
Sunday, March 17, 2013 at 11:02am

Chemistry
how many grams of ammonium sulfate is formed from the complete reaction of 700 grams of ammonie
Sunday, March 17, 2013 at 10:30am

Chemistry - URGENT
So, I go to high school in Texas and we have this AP Chem lab due online tomorrow night by midnight and I need some serious help on these questions: Lab Temp 0.2°C Experiment Trial Time in seconds Trial 1 Trial 2 Average Time 1 1 2 ...
Saturday, March 16, 2013 at 10:44pm

AP Chemistry
A biochemist prepares a lactic acid-lactate buffer by mixing 225 mL of 0.85M lactic acid with a Ka=1.38*10^-4 with 435mL of 0.68M sodium lactate. What is the buffer pH? I know I have to use the equilibrium constant expression, but I'm pretty lost from there. Can someone ...
Saturday, March 16, 2013 at 10:41pm

Chemistry - reaction kinetics
So, I go to high school in Texas and we have this AP Chem lab due online tomorrow night by midnight and I need some serious help on these questions: Lab Temp 0.2°C Experiment Trial Time in seconds Trial 1 Trial 2 Average Time 1 1 2 ...
Saturday, March 16, 2013 at 9:15pm

Chemistry
Suppose it is a hot summer day (40.0 degrees C = 104.0 degrees F), and you have left a can of hairspray outside so the gas within it is now at the same temperature of its surroundings. As part of your chemistry lab class, you have to build a safe and effective potato gun to ...
Saturday, March 16, 2013 at 7:52pm

Chemistry
So, I go to high school in Texas and we have this AP Chem lab due online tomorrow night by midnight and I need some serious help on these questions: Lab Temp 0.2°C Experiment Trial Time in seconds Trial 1 Trial 2 Average Time 1 1 2 256 275 268 ...
Saturday, March 16, 2013 at 6:51pm

Chemistry AP
It was determined that a 0.10 M solution of an acid was only 2.5% ionkzed. Find the Ka and pKa for the acid.
Saturday, March 16, 2013 at 5:59pm

Chemistry
The Ksp of magnesium hydroxide, Mg(OH)2, is 5.61 × 10^-12. Calculate the molar solubility of this compound. Is the answer 1.1*10^-4 M?
Saturday, March 16, 2013 at 4:46pm

Chemistry
How are a mix of pre-1982 and post-1982 pennies a misleading or incorrect analogy for actual element isotopes?
Saturday, March 16, 2013 at 3:43pm

Chemistry
Suppose you have to prepare 1.00 L of the solution ( KH2 PO4 and Na2 HPO4 pH=7.31) and that this solution must be isotonic with blood (have the same osmotic pressure as blood). What mass of KH2 PO4 would you use? b) What mass of Na2 HPO4 . 12 H2O would you use
Saturday, March 16, 2013 at 3:25pm

Chemistry
You are to prepare a KH2PO4 and Na2HPO4 solution with pH=7.31. What should the concentration of [2(HPO4) 2-] / [H2PO4-]
Saturday, March 16, 2013 at 3:20pm

Chemistry
Suppose you have to prepare 1.00 L of the solution ( KH2PO4 and Na2HPO4 pH=7.31) and that this solution must be isotonic with blood (have the same osmotic pressure as blood). What mass of KH2PO4 would you use?
Saturday, March 16, 2013 at 3:16pm

chemistry (Pls Bob check for me)
A 150mg/dl glucose solution was diluted 1:2. Then 0.5ml of it was added to 4.5ml saline. 2ml of this solution was diluted to 10ml. What is the final concentration of glucose? 1L = 10dL 1dL = 100mL My own calculation 150mg/dL = 150mg/100ml =1.5 150mg/100ml x 1/2 x 1/10 x 1/5 1....
Saturday, March 16, 2013 at 3:14pm

Chemistry
A 5.00L reaction vessel is filled with 1.00mol of H2, 1.00mol of I2, and 2.50mol of HI. If equilibrium constant for the reaction is 129 at 500k, what are the equilibrium concentrations of all species? H2(g) + I2(g) <-> 2HI(g) Kc = 129
Saturday, March 16, 2013 at 2:38pm

chemistry (Pls Bob check for me)
A 150 mg/dl glucose solution was diluted 1:2. Then 0.5ml of it was added to 4.5ml saline 2 ml of this solution was diluted to 10ml. What is the final concentration of glucose? 1L= 10dl 1dl =100mL Answer 0.015mg/dl
Saturday, March 16, 2013 at 2:30pm

Pages: <<Prev | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | Next>>

Post a New Question | Current Questions

Homework Help: Science

For Further Reading