Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
In basic solution disproportionate to bromited bromide ions. Use the half reaction method to balance the equation.
Saturday, May 18, 2013 at 9:18am

chemistry
which orbitals have centre of symmetry
Saturday, May 18, 2013 at 8:18am

chemistry
what is the normality and nature of the mixture obtained by mixing 0.62 gram of na2co3.h2o to 100 ml of 0.1N h2so4
Saturday, May 18, 2013 at 4:13am

chemistry
will linear polybutadiene or branched polybutadiene have a higher molar volume?
Saturday, May 18, 2013 at 2:33am

Chemistry
How much 3M H2SO4 can be made from 20ml of 12N H2SO4?
Saturday, May 18, 2013 at 12:04am

chemistry
The equilibrium constant (Ka) for equation 3 at 25 °C is 1.80 × 10−4 mol dm−3. Calculate the equilibrium concentration of hydrogen ions if the concentration of formic acid at equilibrium is 0.00400 mol dm−3. (Show all of your working and give your ...
Friday, May 17, 2013 at 6:29pm

Chemistry
I need this answered really fast. 4. Ethylene glycol (C2H6O2) is used as an antifreeze in cars. If 400 g of ethylene glycol is added to 4.00 kg of water, what is the molality? Calculate how much the freezing point of water will be lowered. The freezing-point depression ...
Friday, May 17, 2013 at 4:45pm

Chemistry
How many grams of CaCl2 are needed to make 100ml of a 15% solution in water if only the dihydrated (CaCl2 •2H20) salt is available?
Friday, May 17, 2013 at 4:32pm

World History
1. The purpose of American and European imperialism in the Pacific was mainly to gain. A. markets fro manufactured products B. coaling stations and naval bases C. sources of raw materials D. places for surplus population I said C. 2. The development of antiseptics during the ...
Friday, May 17, 2013 at 3:39pm

Easy chemistry
Whats the charge on a carbon cation?? I believe it is a positive charge, but does it have a number along with it?? not sure..
Friday, May 17, 2013 at 12:06pm

CHEMISTRY
commercial HCL IS SOLD AT 37% WITH SPECIFIC GRAVITY OF 1.18.HOW WILL YOU PREPARE 5OML FOR 100STUDENTS AT THE CONCENTRATION OF 0.25M
Friday, May 17, 2013 at 7:41am

CHEMISTRY
commercial HCL IS SOLD AT 37% WITH SPECIFIC GRAVITY OF 1.18.HOW WILL YOU PREPARE 5OML FOR 100STUDENTS AT THE CONCENTRATION OF 0.25M
Friday, May 17, 2013 at 7:40am

chemistry
if 10 metric tons of silver nitrate is produced, how much would i need to charge per metric ton of silver nitrate to break even
Friday, May 17, 2013 at 7:03am

Chemistry
0.80 mol/L of A and B are mixed. They react very slowly to produce C and D as follows: A(aq) + B(aq) ⇔ C(aq) + 2D(aq) When equilibrium is attained, the concentration of C is 0.60 mol/L and the concentration of A is: a) 0.20 M b) 0.40 M c) 0.60 M d) 0.80 M
Friday, May 17, 2013 at 12:47am

chemistry
If we have a concentration of H+ at 5 x 10-2 mol/L, what is the pH value?
Thursday, May 16, 2013 at 7:56pm

Chemistry
Equal moles of nitric acid (HNO3) and formic acid (HCOOH) were each dissolved in equal volumes of water. State and explain which of the resulting solutions would have the higher pH. Your answer should include an explanation of the terms strong acid and weak acid and a ...
Thursday, May 16, 2013 at 4:58pm

Chemistry
What is the hydrogen ion concentration, in mol dm−3, when 2.00 g of sulfuric acid is dissolved in water to give 0.400 dm3 of solution?
Thursday, May 16, 2013 at 4:40pm

CHEMISTRY
A diatomic ideal gas is heated at constant volume until its pressure becomes 3 times.it is again heated at constant pressure until its volume is doubled.find the molar heat capacity for the whole process?
Thursday, May 16, 2013 at 3:50am

chemistry
Describe the preparation of 2litre of 0.05molar silver from the primary standard grade solid.
Thursday, May 16, 2013 at 3:05am

Chemistry
Calculate the pressure exerted by a 14.6 mol NH3g in a 3.2 L container at -15.0 celcius using the Van der Waals equation.
Wednesday, May 15, 2013 at 8:37pm

URGENT CHEMISTRY
Which of the following pairs of compounds will give a precipitate in a diluted solution? Question 4 options: A) Cu(NO3)2 and Na2CO3 B) KNO3 and NaCl C) MgCl2 and Ba(NO3)2 D) NH4Cl and Al2(SO4)3 ALL OF THEM ARE SOLUBLE? WHAT DO I DO?
Wednesday, May 15, 2013 at 7:37pm

Chemistry Help Please
The concentration of hydroxide ions in a solution of nitric acid 0.2 M is: a. 2 x 10-14 M b. 5 x 10-14 M c. 5 x 10-7 M d. 2 x 10-1 M IS IT D)?
Wednesday, May 15, 2013 at 6:47pm

chemistry
What are [H+] and [OH-] for 0.01 M perchloric acid
Wednesday, May 15, 2013 at 6:45pm

Chemistry
CaCO3(s) <-> CaO(s) + CO2(g) What would happen if CO2 was removed? Would the reaction shift left? Does that mean CaCO3 increases and CaO and CO2 decrease ?
Wednesday, May 15, 2013 at 5:18pm

Chemistry - Le Chateli.
3Fe(s) + 4H2O(g) <-> Fe3O4(s) + 4H2(g) What happens when Fe(s) is added? Would the reaction shift right?
Wednesday, May 15, 2013 at 5:15pm

chemistry
a balloon has a volume of 456 mL at a pressure of 1.0 atm. it is taken under water in a submarine to depth. where the air pressure in the submarine is 3.3 atm. what is the volume of the balloon? assume constant temperature?
Wednesday, May 15, 2013 at 2:05pm

chemistry
balanced equation for the reaction of HNO3 + STARCH +KI
Wednesday, May 15, 2013 at 1:35pm

physics/chemistry(Thermodynamics)!!!!!helppppp!
In a certain chemical process,a lab technician supplies 254 j of heat to a system. At the same time,73 j of work are done on the system by iys surroundings.What is the increase in the internal energy of the system?
Wednesday, May 15, 2013 at 9:57am

Chemistry
Is there a difference between SiO2(aq) and H4SiO4?
Wednesday, May 15, 2013 at 9:44am

chemistry
Islands in the middle of the oceans (for example, Great Britain, Hawaii, Bermuda) tend to have more stable climates with smaller temperature fluctuations than regions of the same mass surrounded by land (for example, continents). Use your knowledge of heat energy, specific ...
Wednesday, May 15, 2013 at 9:38am

chemistry
The surface tension versus log concentration for two surfactants are shown below. Describe in not more than 5 sentences how the two surfactants can be so different.
Wednesday, May 15, 2013 at 8:13am

Chemistry; -_-
Help? How would you do these? /: Draw electron dot diagrams for the following: Na Mg As F Ne
Wednesday, May 15, 2013 at 4:43am

PHYSICS/CHEMISTRY
Can someone explain to me, what does Metastable isotope means? I already read the definitions on the internet but I really don't understand it. Thanks in advance.
Tuesday, May 14, 2013 at 9:22pm

chemistry
balance the net ionic equation for the overall reaction. Pt | Fe2+(aq), Fe3+(aq) || I-(aq) | AgI(s) | Ag(s) a) Fe3+(aq) + Ag(s) + I-(aq) → Fe2+(aq) + AgI(s) b) Fe2+(aq) + Ag(s) + I-(aq) → Fe3+(aq) + AgI(s) c) Fe3+(aq) + AgI(s) → Fe2+(aq) + Ag(s) + I-(aq) d) ...
Tuesday, May 14, 2013 at 7:19pm

Chemistry
How to calculate Q in Nernst Equations, we used 0.10M solutions in all of our half cells. Nernst equation: Ecell = E0cell - RT/nF ln Q Overall reactions: Cu(s) + Pb2+(aq) ~ Cu2+(aq) + Pb(s) and 3Pb(s) + 2Al3+ ~ 3Pb2+ 2Al(s) Thank you!
Tuesday, May 14, 2013 at 5:54pm

Chemistry
How Many molecules Of sodium are contained in 2 L Of sodium dichromate? The density Of sodium dichromate is 3.7 g/ml
Tuesday, May 14, 2013 at 4:20pm

chemistry
5. Meals-ready-to-eat (MREs) are military meals that can be heated on a flameless heater. The heat is produced by the following reaction: Mg(s) + 2H2O(l) --> Mg(OH)2(s) + H2(g) Calculate the number of grams of Mg needed for this reaction to release enough energy to increase...
Tuesday, May 14, 2013 at 3:49pm

chemistry
4. A 35.0 mL sample of 1.00 M KBr and a 60.0-mL sample of 0.600 M KBr are mixed. The solution is then heated to evaporate water until the total volume is 50.0 mL. What is the molarity of the KBr in the final solution?
Tuesday, May 14, 2013 at 3:48pm

chemistry
3. When a mixture of 10.0 grams of acetylene (C2H2) and 10.0 grams of oxygen (O2) is ignited, the resulting combustion reaction produces CO2 and H2O. A) Write a balanced equation for this reaction. B) What is the limiting reactant? C) How many grams of C2, H2, O2, CO2, and H2O...
Tuesday, May 14, 2013 at 3:47pm

Chemistry
Is Cl2 + 2e- -> 2Cl- an oxidation half-reaction?
Tuesday, May 14, 2013 at 3:33pm

Chemistry
Is Cl2 + 2e- -> 2Cl- an oxidation half-reaction?
Tuesday, May 14, 2013 at 3:28pm

chemistry
how much of 0.1 M NaOH is needed to neutralize 5mL of 0.1 M of HCL to a ph 7(color on the ph scale)...Thank you
Tuesday, May 14, 2013 at 1:07pm

Chemistry
0.1 mol of HCl is added to 1 L of water. What is [H+] and [OH-]?
Tuesday, May 14, 2013 at 12:37pm

chemistry
If 15 grams of table salt is used how many moles of sodium sulfate are produced
Tuesday, May 14, 2013 at 12:35pm

Chemistry
How many grams of barium nitrate is needed to form a solution with 5.00 mass% Ba (NO3)2 in 400 grams of water.
Tuesday, May 14, 2013 at 11:35am

chemistry
A 211 g sample of barium carbonate, BaCO3, reacts with a solution of nitric acid to give bar- ium nitrate, carbon dioxide and water. If the acid is present in excess, what mass and volume of dry carbon dioxide gas at STP will be produced
Tuesday, May 14, 2013 at 4:22am

Chemistry
Using your experimental data, calculate E0cell. Standard voltaic cells contain 1M solutions, but we used 0.10M solutions in all of our half cells. Use the Nernst equation to calculate the standard cell potential (E0cell) from your measured Ecell and Qrxn. Data: Nernst Equation...
Tuesday, May 14, 2013 at 2:24am

Science (chemistry) help please
The following data was obtained from titrating a solution containing 25 mL of 0.0100 M MgCl2 solution, 1 mL of NH3OH buffer, and 10 drops of Calmagite with EDTA. Calculate the concentration of EDTA. Report the answer with three sig figs. I don't know what to do? I know ...
Tuesday, May 14, 2013 at 1:47am

Chemistry
How many grams of gas are present in a sample that has a molar mass of 70 g/mol and occupies a 2 L container at 117 kPa and 35.1C?
Monday, May 13, 2013 at 11:16pm

Chemistry
I am dealing with the integrated rate laws. Can somebody please help me with my algebra? First order ln(A)=-kt+ln(B) solve for t,and k and B Second order 1/(A) = kt+1/(B) solve for k and t and B
Monday, May 13, 2013 at 10:53pm

chemistry
The reaction of chlorine gas with solid phosphorus (P4) produces solid phosphorus pentachloride. When 63.5 g chlorine reacts with 28.5 g P4, which reactant is limiting?
Monday, May 13, 2013 at 9:50pm

chemistry
If something originally contained 32.0 g of Po-210, which has a half-life of 10.5 minutes, and was now 73.5 minutes old, how many grams would be left?
Monday, May 13, 2013 at 8:57pm

chemistry
What volume of 31.5 grams of molecular element,chlorine gas, occupy at a pressure of 1.29 atm and temperature of 20 degrees cesius, assuming that the behavior of chlorine gas is ideal?
Monday, May 13, 2013 at 7:53pm

Chemistry
.012 mol of solid NaOH is added to a 1 L solution of HCl 0.01 M. What is the pH of the solution?
Monday, May 13, 2013 at 7:17pm

Chemistry
How much water, in grams, can be made from 6.82 × 1024 hydrogen molecules? Answer in units of g
Monday, May 13, 2013 at 6:08pm

Chemistry
An unknown amount of water is mixed with 350 mL of a 6 M solution of NaOH solution. A 75 mL sample of the resulting solution is titrated to neutrality with 51.2 mL of 6 M HCl. Calculate the concentration of the diluted NaOH solution. Answer in units of M What volume of water ...
Monday, May 13, 2013 at 6:07pm

Chemistry
The following data was obtained from titrating a solution containing 25 mL of 0.0100 M MgCl2 solution, 1 mL of NH3OH buffer, and 10 drops of Calmagite with EDTA. Calculate the concentration of EDTA. Report the answer with three sig figs. Please help it only shows a graph with ...
Monday, May 13, 2013 at 6:07pm

Chemistry
What is the concentration of NO− 3 after mixing? Answer in units of mol/L
Monday, May 13, 2013 at 6:06pm

Chemistry
Three solutions 56.0 mL of 0.6 M KNO3; 77.0 mL of 0.6 M Ca(NO3)2; and 42.0 mL of 0.29 M KCl were poured together to make one new solution. What is the concentration of Cl− after mixing? Answer in units of mol/L
Monday, May 13, 2013 at 6:05pm

Chemistry
In the titration of 14.0 mL of 0.10M acetic acid with 0.40 M NaOH, (A) How many mL of NaOH needed to completely neutralize the acid? Given the balanced equation: CH3COOH (aq) + NaOH (aq) 􏰀 CH3COO Na (aq) + H2O
Monday, May 13, 2013 at 5:11pm

chemistry
3.Suppose the innermost orbit an electron can occupy has an energy level of -19 eV. Based on the absorption spectrum shown below, what is the energy of energy level 4?
Monday, May 13, 2013 at 3:35pm

chemistry
what volume of carbon dioxide is formed when 11 of CS2 reacts with 18 L O2 to produce carbon dioxide gas and sulfur dioxide gas at STP?
Monday, May 13, 2013 at 3:24pm

Chemistry
Find the enthalpy for : 4Fe + 3O2 = 2Fe2O3 I got the following informations: Fe + 3H2O = Fe(OH)3 + 3/2H2 - Enthalpy is 160.9 kj H2 + 1/2O2 = H2O - Enthalpy is -285.8 kj Fe2O3 + 3H2O = 2Fe(OH)3 - Enthalpy is 288.6 I try using Hess Law but cannot solve it. Can anyone help me ...
Monday, May 13, 2013 at 2:37pm

Chemistry
How many moles of sulfuric acid are required to neutralize 0.80 mol of sodium hydroxide? H2SO4 + 2NaOH -> Na2SO4 + 2H2O I got 0.40 mol. Is this right?
Monday, May 13, 2013 at 2:35pm

chemistry
Physicain elects to re-hydrate the patient br intravenous(IV) administration of 2.0 L of 0.45% (w/v) of NaCl. 0.45%9w/v) = 0.45g/100ml A.How many grams of NaCl were given? B.How many moles of Nacl were given? C.What is the molarity of the NaCl solution?
Monday, May 13, 2013 at 2:26pm

chemistry
a sample of 15.00 g of an unkown metal chloride, MCl2 is dissolved in 75.0 mL water. the boiling point of the resulting solution is measured at 102.37 degrees C. what is the identity of the metal M.
Monday, May 13, 2013 at 1:28pm

physics/chemistry(kinetic ..gasses)
How many degreed of freedom have the gas molecules,if under standard conditions the gas dendity is 1.3kg/m^3 and velocity of sound propagation on it is v=330m/s?
Monday, May 13, 2013 at 10:58am

chemistry
balance the equation and name the reaction taking place C3H5OH+O2 equals CO2+ H2O
Monday, May 13, 2013 at 10:44am

chemistry
What is the molarity of the acetic acid if 0.5ml of a vinegar solution has been titrated with the 0.101M solution of NaOH and the volume of the NaOH solution at the equivalence point is 5.0mL?
Monday, May 13, 2013 at 8:59am

Chemistry
If I used 100% larger sample mass of an unknown substance what effect would that have on the empirical formula that would be obtained?
Monday, May 13, 2013 at 2:20am

chemistry - thank you:)
What volume of H2SO4 0.04 M is required to completely neutralize 200 mL of Al(OH)3 0.02M?
Monday, May 13, 2013 at 1:51am

Chemistry
An 800-mg sample containing sulfate was treated with slight excess of barium chloride, yielding a precipitate that contained 4.3 mg of co precipitated CaCO3. after ignition and cooling, the precipitate weighed 277.0 mg. Calculate the a.) apparent % SO4 b.) true % SO4 and c.) ...
Sunday, May 12, 2013 at 11:19pm

Chemistry
If it takes 54 mL of 0.1 M NaOH to neutralize 125 mL of an HCI solution, what is the concentration of the HCI?
Sunday, May 12, 2013 at 10:39pm

Chemistry
Two gases effuse through a hole. Gas A has 9 times the molecular mass of gas B. What is the ratio of the two molecular speeds?
Sunday, May 12, 2013 at 8:02pm

Chemistry
2.76 grams of silver carbonate produced a 50 percent yield of silver oxide. what is the actual mass of this reaction
Sunday, May 12, 2013 at 7:16pm

Chemistry
how many grams of phosphorus pentachloride are needed to produce 49 grams of phosphoric acid.
Sunday, May 12, 2013 at 7:15pm

chemistry
calculate the heat energy required to raise the temperature of a 500. gram iron pipe from 25 degress celcius to 100 degrees celcius. the specific heat for iron is .45 J/g degrees celcius
Sunday, May 12, 2013 at 4:41pm

chemistry
Calculate Ecell forthe following electrochemical cell at 25 C Pt(s) |H2(g, 1.00 bar) |H + (aq, 1.00 M) || Pb2+(aq, 0.150 M) | Pb(s)
Sunday, May 12, 2013 at 3:52pm

chemistry
write a balanced net ionic equation for the overall reaction represented by the cell notation below. Pt/ Fe2+, Fe3+ // I-/AgI/Ag
Sunday, May 12, 2013 at 3:07pm

chemistry (ionic eq.)
what mass of Pb^2+ ion is left in solution when 50 ml of 0.2M PbCl2 is added to 50ml of 1.5 NaCl?[Ksp for PbCl2= 1.7* 10^(-4)]
Sunday, May 12, 2013 at 2:03pm

physical chemistry
The system N2O4 <--->2NO2 maintained in a closed vessel at 60º C & a pressure of 5 atm has an average (i.e. observed) molecular weight of 69, calculate Kp. At what pressure at the same temperature would the observed molecular weight be (230/3)
Sunday, May 12, 2013 at 11:41am

Chemistry
How many grams of nitric acid (HNO3) must be dissolved in 740 mL of water to make a solution with a pOH = 8.3?
Sunday, May 12, 2013 at 11:29am

chemistry
14. The reaction H2S (aq) = HS-(aq)+ H+(aq) has pK = 7 at 298 K, 1bar. Consider a solution in which total dissolved sulfur is 10^-5 molal. At pH = 3, pH2S =
Sunday, May 12, 2013 at 9:05am

chemistry
consider a iodometric titration. why we add starch indicator just before the end point????. why cannot we add it before we start the titration???
Sunday, May 12, 2013 at 7:21am

Chemistry
If 1 mol L of 2.0 mol L hydrochloric acid is diluted to form a solution with concentration 0.2 mol L, A. What is the final volume? B. how much water must be added to the original acid? Use C1V1= C2V2, thanks in advance
Saturday, May 11, 2013 at 9:58pm

chemistry
Balance the following redox reaction. MnO4 (aq) + Fe (s) --> Mn2+ (aq) +Fe2+ (aq)
Saturday, May 11, 2013 at 5:17pm

Chemistry
The oxygen gas emitted from an aquatic plant during photosynthesis is collected over water at a temperature of 25 degrees Celcius and a total pressure of 752 torr. What is the partial pressure of the oxygen gas?
Saturday, May 11, 2013 at 3:27pm

Chemistry
Determine the theoretical and percent yield of hydrogen gas if 78.5 g water undergoes electrolysis to produce hydrogen and oxygen and 3.23 g hydrogen is collected.
Saturday, May 11, 2013 at 12:04pm

Chemistry
Make a solution of the following: 4ml of 0.5m cupric sulphate pentahydrate. 5ml of 250mm cupric sulphate pentahydrate. and 6ml of 125mm cupric sulphate pentahydrate.
Saturday, May 11, 2013 at 10:01am

CHEMISTRY HELP!!!
A silver ring is dropped in a solution of Pb(NO3)2 for a certain period. Will you find it intact? Explain.
Saturday, May 11, 2013 at 1:52am

chemistry
Can a solution of CrCl3 be stored in an aluminum container?
Saturday, May 11, 2013 at 12:22am

chemistry
A solution contains 25.5 g of NaCl dissolved in sufficient water to give a total mass of 325.0 g. What is the molality of the solution
Friday, May 10, 2013 at 11:29pm

chemistry
A solution of ethanol, C2H5OH, is prepared by dissolving 25.0 mL of ethanol in enough water to give a total volume of 250.0 mL. What is the percent-by-volume concentration of ethanol?
Friday, May 10, 2013 at 10:44pm

CHEMISTRY
The two half-reactions for the LeClanche dry cell battery are shown below. Describe the direction of spontaneous electron flow in this electrochemical cell. Zn(s) ---> Zn2+(aq) + 2e- 2NH4+(aq) + 2e- ---> 2NH3(g) + H2(g)
Friday, May 10, 2013 at 6:13pm

Chemistry
77.0 mL of a 1.20 M solution is diluted to a total volume of 288 mL. A 144-mL portion of that solution is diluted by adding 155 mL of water. What is the final concentration? Assume the volumes are additive.
Friday, May 10, 2013 at 5:42pm

Chemistry pH
What is the pH of a solution that is .60 M H2SO4 (Sulfuric acid) and 1.7 M HCOOH (formic acid).
Friday, May 10, 2013 at 1:55pm

CHEMISTRY Homework Assignment
Hi I noticed someone else put this question up, but I am having a hard time with this one. I HAVE NO IDEA WHAT TO DO. What will be the products of the electrolysis of an aqueous solution of zirconium iodide (ZrI4)? (The electrodes themselves are platinum.)
Friday, May 10, 2013 at 12:23pm

CHEMISTRY Homework
What will be the products of the electrolysis of an aqueous solution of zirconium iodide (ZrI4)? (The electrodes themselves are platinum.)
Friday, May 10, 2013 at 12:00pm

Chemistry Question
Calculate the ∆G˚ for the oxidation of nickel in the following balanced reaction. 2[RhCl6]3-(aq)+ 3Ni a 2Rh(s) + 3NiCl2(aq) + 6Cl-(aq) E˚ for RhCl6 is 0.5V E˚ for Ni(s) is -0.25V
Friday, May 10, 2013 at 10:39am

College Chemistry 104
Students are attempting to construct a battery in the laboratory that will light up a light bulb. Compare the following lists prepared by students and determine which student will not be able to successfully build a "battery" that will light up the bulb. Student 1 ...
Friday, May 10, 2013 at 10:28am

chemistry
When heated, elemental phosphorus, P4, produces phosphine, PH3, and phosphoric acid, H3PO4. How many grams of phosphine are produced if 56 grams of P4 have react
Friday, May 10, 2013 at 10:27am

Chemistry
under the same conditions of temperature and pressure , does hydrogen iodide and ammonia diffuse faster? calculate the ratio of the velocities
Friday, May 10, 2013 at 8:40am

chemistry
for an aqueous solution having Calcl2 (2molar) and Mgcl2 (5molal) and specified gravity of solution is 1.145 calculate molality of chloride ion and molality if chloride ion.
Friday, May 10, 2013 at 4:54am

Chemistry Help Please
Which pair of ions will be most likely to react at standard state conditions? a) MnO4- and Sn2+ b) Zn2+ and Cl- c) I- and Cu d) Fe3+ and Cu2+
Thursday, May 9, 2013 at 11:47pm

Chemistry
What's is the concentration of silver ions in a saturated solution of silver carbonate? The k^sp of Ag2CO3 is 8.1x10^ -12. Is the answer 5.88x10^-8? I have a test tomorrow and I really need to make sure I'm doing these problems right, but I feel like I am not.
Thursday, May 9, 2013 at 10:56pm

Chemistry
Name the compounds CH3CH2CHCH2CH3 - Is this 3-Pentane? Thanks
Thursday, May 9, 2013 at 10:06pm

Chemistry
What is the molarity of a solution prepared by dissolving 5.86 grams of naoh in enough water to make 250 milliliters of solution
Thursday, May 9, 2013 at 4:35pm

Chemistry
1.What mass of NaOH(s) must be added to 300 mL of HCl 0.25 M in order to completely neutralize this acid? 2.During a lab, you mix 2 solutions: a 100 ml solution containing 0.40 g of NaOH and a 100 mL solution containing 0.73 g of HCl. What is the concentration of H+ ions in ...
Thursday, May 9, 2013 at 2:22pm

chemistry
The surface tension versus log concentration for two surfactants is shown below. Describe in no more than five sentences how the two surfactants can be so different. You have only one attempt at this problem.
Thursday, May 9, 2013 at 1:43pm

chemistry
A volume of 50.0 ml of gas is collected by displacement of mercury at 17 degrees Celsius and 760 mm pressure. The mercury level inside the eudiometer is 30.0 mm higher than the outside. What volume will the gas occupy at STP?
Thursday, May 9, 2013 at 11:53am

chemistry
a)Calculate the pH of a solution of 0.75 M HNO3, which is a strong acid. b)Calculate the pH of a 1.0 L aqueous solution made from 0.80 mol CH3COOH and 0.20 mol KCH3COO (Ka = 1.8 x 10^-5).
Thursday, May 9, 2013 at 9:36am

CHEMISTRY
how would a chemistry student make a 600 mL of 1.5 M solution of NaBr?
Thursday, May 9, 2013 at 4:21am

chemistry
A mixture consisting of 0.150 M N2(g) and 0.612 M H2(g) reacts and then reaches equilibrium according to the equation: N2(g) + 3H2(g) ⇋ 2NH3(g) At equilibrium, the concentration of ammonia is 0.213 M. Calculate the concentration (molarity) of H2(g) at equilibrium to 3 ...
Thursday, May 9, 2013 at 3:56am

Chemistry Help Please
Which of the following is the strongest reducing agent? a) Li+ b) Zn c) Sn d) H2 Is it Li? Can someone please explain what the answer is and why?
Thursday, May 9, 2013 at 2:48am

chemistry
a gas occupies 37.6 L at 2.00 atm pressure and 27C degrees. how many moles of gas are present in this sample
Wednesday, May 8, 2013 at 9:40pm

chemistry
a sample of oxygen gas has a volume of 7.64 L at a temperature of 19C and a pressure of 1.38 atm. Calculate the moles of O2 present in this gas sample
Wednesday, May 8, 2013 at 9:38pm

chemistry
11.During an acid-base titration, 25 mL of NaOH 0.2 M were required to neutralize 20 mL of HCl. Calculate the pH of the solution for each of the following: 12.Before the titration. 13.After adding 24.9 mL of NaOH. 14.At the equivalence point. 15.After adding 25.1 mL of NaOH. ...
Wednesday, May 8, 2013 at 9:18pm

Chemistry
How many moles of potassium hydroxide are required to neutralize 1.25 mol of phosphoric acid? H3PO4 + 3KOH -> K3PO4 +3H2O I got 0.42 mol KOH , is this correct? thanks!
Wednesday, May 8, 2013 at 5:25pm

HELP! CHEMISTRY
Which one of the following species will react with Sn at standard state conditions? a) S b) Ag+ c) Cu d) Zn2+ What does it mean by standard state conditions? And what do I have to look at to determine it? Would it be Zn2+?
Wednesday, May 8, 2013 at 5:22pm

chemistry
A. Find and list all of the different half- cell combinations. Hint 15 combinations! 1. Copper/ Cu2+ 2. Lead/ Pb2+ 3. Magnesium/ Mg2+ 4. Zinc/ Zn2+ 5. Iron/Fe2+ 6. Aluminum/ Al3+ B. write the half reactions of each combination and the overall redox reaction. Please help! Thank...
Wednesday, May 8, 2013 at 3:45pm

Chemistry
A saturated solution of potassium nitrate in water is prepared at 70.0*C then cooled to 55.0*C how many grams of potassium nitrate crystallized--- how do I determine this using my graph with everyone's numbers
Wednesday, May 8, 2013 at 3:17pm

Chemistry
Consider a generic redox reaction then suppose that the coefficients in the redox reaction are doubled. How will the following quantities be affected for a voltaic cell under nonstandard conditions, will they be Doubled, Halved, Squared, or No Change. Note that n is written as...
Wednesday, May 8, 2013 at 1:43pm

chemistry
how to determine the oxalate and copper in K[Cu(C2O4)2].2H2O
Wednesday, May 8, 2013 at 11:49am

Ap chemistry
What is the approximate molar fraction of ethanol c2h5oh in an aqueous solution in which the ethanol concentration is 11.0 molal? A. 0.0011 B. 0.011 C. 0.170 D. 0.200 E. 0.600
Wednesday, May 8, 2013 at 10:11am

chemistry
Sodium dodecyl sulfate (SDS) has the structure below. The surface tension of water changes as SDS is added, as shown in the graph below. (a) Why does the surface tension of water change as SDS is added? The number of micelles increases, which allows the non-polar tails of SDS ...
Wednesday, May 8, 2013 at 9:05am

Chemistry
A beaker is filled with Ammonia (NH3) and Hexane. A surfactant with a polar head group and non-polar tail is added to the mixture, and the beaker is agitated and then allowed to equilibrate. The values of density are 0.65 g/cm3 for hexane and 0.60 g/cm3 for liquid ammonia. ...
Wednesday, May 8, 2013 at 8:44am

chemistry
if the endpoint in the tritration of the KHC8H4O4 solution with the NaOH solution is mistakenly surpressed(too pink),will the molar concentration of the NaOH solution be reported too high or too low?explain
Wednesday, May 8, 2013 at 4:27am

chemistry
please i need example of hno3 cuo
Wednesday, May 8, 2013 at 4:10am

chemistry
Consider the polymer polybutadiene. (a) Will linear polybutadiene or branched polybutadiene have a higher molar volume? (b) Will linear polybutadiene or branched polybutadiene have a higher glass transition temperature? (c) Will linear polybutadiene or branched polybutadiene ...
Wednesday, May 8, 2013 at 3:42am

Chemistry
Explain why iron corrodes more quickly in seawater than in freshwater. I'm getting conflicting answers from searching on Google; is it because the corrosion of iron is a redox reaction, which involves a transfer of electrons, and therefore this transfer of electrons would ...
Tuesday, May 7, 2013 at 11:27pm

chemistry
A sample of an ideal gas has a volume of 2.29 L at 2.90 × 102 K and 1.08 atm. Calculate the pressure when the volume is 1.57 L and the temperature is 302 K.
Tuesday, May 7, 2013 at 10:43pm

Chemistry
An antacid tablet containing magnesium hydroxide instead of calcium carbonate was dissolved in 100.0 mL of 0.2893 M HCL. 10 mL of this solutions was titrated to endpoint with 25.20 mL of 0.1007 M NaOH. How much magnesium hydroxide was in the antacid tablet(in mg)? Any help is ...
Tuesday, May 7, 2013 at 9:28pm

Chemistry
A gas occupying a volume of 664 mL at a pressure of 0.970 atm is allowed to expand at constant temperature until its pressure reaches 0.541 atm. What is its final volume?
Tuesday, May 7, 2013 at 9:27pm

Chemistry
The voltage generated by the zinc concentration cell described by, Zn(s)|Zn2 (aq, 0.100 M)||Zn2 (aq, ? M)|Zn(s) is 23.0 mV at 25°C. Calculate the concentration of the Zn2 (aq) ion at the cathode. Can someone please breakdown how to do this so I can figure out the rest of ...
Tuesday, May 7, 2013 at 6:31pm

chemistry
If the endpoint in the titration of KHC8H4O4 solution with the NaOH solution is mistakenly surpassed, will the molar concentration of NaOH solution be reported too high or too low?
Tuesday, May 7, 2013 at 3:27pm

chemistry
a stone is thrown vertically upwards from the edge of a tower with velocity 5m/s.it strikes the ground close to the base after 4s .the height of tower?
Tuesday, May 7, 2013 at 3:23pm

Chemistry
Explain, not just describe, the relationship between these rankings. Most reactive to least reactive metals: Zn, Pb, Cu, Ag Most reactive to least reactive metal cations: Ag, Cu, Pb, Zn
Tuesday, May 7, 2013 at 2:34pm

Chemistry
Which two elements is the second transition series (y through Cd) have four unpaired electrons in their 3+ ions?
Tuesday, May 7, 2013 at 1:40pm

Chemistry
An unknown solid acid is either citric acid or tartaric acid. To determine which acid you have, you titrate a sample of the solid with NaOH. The appropriate reactions are as follows: Citric acid: H3C6H5O7 (aq) + 3NaOH (aq) -> 3H2O (l) + Na3C6H5O7 (aq) Tartaric acid: ...
Tuesday, May 7, 2013 at 1:25pm

Chemistry
Estimate how many microwave photons with 1=12 cm must be absorbed to raise the temperature of your eye by 3 degree C. Assume the mass of an eye is 11 g and its specific heat capacity is 4.0 J/g/k
Tuesday, May 7, 2013 at 1:19pm

Chemistry
One chirality of CH3CHCICOOH is shown below. COOH | C H3C/ \CI - - - H Identify the image(s) below that excibit the opposite chirality. Select all that apply. (a) COOH (b) H | | C C _ | _ / \ _ | _ H3C CI _ | _ _ _ | _ _ CI | CH3 _ H COOH (c) CI (d) COOH | | C C / \ / \ H COOH...
Tuesday, May 7, 2013 at 1:04pm

Chemistry
A substance releases 496kJ of heat as 2.60 moles condense from a gas into a liquid. What is the molar heat of vaporization of the substance?
Tuesday, May 7, 2013 at 12:14pm

Chemistry
A voltaic cell consists of a Pb/Pb2+ half-cell and a Cu/Cu2+ half-cell at 25 C. The initial concentrations of Pb+2 and Cu+2 are 0.0500 M and 1.50 M, respectively. A. What is the initial cell potential? B. What is the cell potential when the concentration of Cu+2 has fallen to ...
Tuesday, May 7, 2013 at 11:54am

College Chemistry 104
A voltaic cell consists of a Pb/Pb2+ half-cell and a Cu/Cu2+ half-cell at 25 C. The initial concentrations of Pb+2 and Cu+2 are 0.0500 M and 1.50 M, respectively. A. What is the initial cell potential? B. What is the cell potential when the concentration of Cu+2 has fallen to ...
Tuesday, May 7, 2013 at 11:50am

Chemistry
What is the equilibrium constant for the reaction: Si + O2 <-> SiO2 ? Is the answer just [SiO2]/[Si][O2] ?
Tuesday, May 7, 2013 at 11:31am

chemistry
The density of CO2 (g) at 25°C and 715 torr is:
Tuesday, May 7, 2013 at 11:23am

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