Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

ap chemistry
Use the Clausius-Clapeyron equation to cal- culate the temperature at which pure water would boil at a pressure of 434 torr. The heat of vaporization of water is 41276 J/mol at 100C. Answer in units of C
Monday, April 15, 2013 at 6:30pm

ap chemistry
Benzene is a hydrocarbon that is commonly used as a commercial solvent. However, it is carcinogenic; i.e., accumulations in the body can cause cancer. What is the vapor pressure of benzene at 29C? The normal boiling point of benzene is 80.0C and its molar heat of ...
Monday, April 15, 2013 at 6:28pm

chemistry
A 3.00 Liter tank containing 225 grams of oxygen gas was heated to 100 degrees C. How much pressure must the tank be able to withstand to avoid explosion of the tank?
Monday, April 15, 2013 at 6:28pm

chemistry
At 1225 kpa, the temperature of a hot air balloon is about 500 degrees Celsius and is inflated to 200 cubic centimeters. Upon descending the pressure is decreased to 9 atm and 300 degrees Celsius. What is the new volume? Round to the nearest whole number, - for example 98.
Monday, April 15, 2013 at 6:27pm

Chemistry
a 20.0ml sample of HCL solution is placed in a flask with a few drops of indicator. If 30.0ml of a 0.240 M NaOH solution is needed to reach the endpoint, what is the molarity of the HCL solution?
Monday, April 15, 2013 at 5:43pm

Chemistry
A gas occupies a volume of exactly 500mL at STP. What would it occupy at exactly 70 degrees celsius and 400 mm of pressure?
Monday, April 15, 2013 at 5:20pm

Chemistry
If a small stream of liquid A was strongly deflected by a charged object, liquid B was moderately deflected, and liquid C was weakly deflected rank the liquids in order of polarity. (Assume densities and charges are all equal.)
Monday, April 15, 2013 at 3:03pm

Chemistry
A balloon contains 2000mL of helium gas at 300K what is the new volume in mL at 600K
Monday, April 15, 2013 at 2:52pm

chemistry
Given the chemcal equation:2 Ca+O2>2 CaO,if 2 moles of CaO are formed in this reaction,then 2 moles of O2 must have reacted. True or False?
Monday, April 15, 2013 at 2:10pm

chemistry
Given the chemcal equation:2 Ca+O2>2 CaO,if 2 moles of CaO are formed in this reaction,then 2 moles of O2 must have reacted. True or False?
Monday, April 15, 2013 at 2:09pm

chemistry quick homework help
A sample of Freon-12 (CF2Cl2) occupies 2.507 x 101 L at 291 K and 2.518 x 102 kPa. Find its volume (in L) at standard temperature and pressure (STP).
Monday, April 15, 2013 at 12:21pm

chemistry
A solution was prepared by dissolving 0.834 g of sulfur, S8, in 100.0 g of acetic acid, HC2H3O2. Calculate the freezing point and boiling point of the solution. (Use the table from the textbook.)
Monday, April 15, 2013 at 11:45am

chemistry
Arginine vasopressin is a pituitary hormone. It helps regulate the amount of water in the blood by reducing the flow of urine from the kidneys. An aqueous solution containing 21.6 mg of vasopressinin 100.0 mL of solution has an osmotic pressure at 25 ¢ªC of 3.70 mmHg...
Monday, April 15, 2013 at 11:43am

chemistry
What is the molality of a solution which contains 20.0 g of cane sugar, C12H22O11 dissolved in125g of water?
Monday, April 15, 2013 at 11:42am

chemistry
Determine the mole fractions of both substances in a solution containing 36.0 g of water and 46.0 gof glycerin, C3H5(OH)3?
Monday, April 15, 2013 at 11:41am

Chemistry
In the reaction, K2Cr2O7 +14 HCl ----> 2KCl + 2CrCl3 + 3Cl2 + 7H2O how many moles of HCl act as reducing agent in balanced chemical equation?
Monday, April 15, 2013 at 11:39am

Chemistry
The number of moles of KMnO4 required to react with 5 moles of H2O2 in acidic medium is ?
Monday, April 15, 2013 at 11:35am

chemistry
What is the vapor pressure at 23 ¢ªC of a solution of 1.20 g of naphthalene, C10H8, in 25.6 g of benzene, C6H6? The vapor pressure of pure benzene at 23 ¢ªC is 86.0 mmHg; the vapor pressure of naphthalene can be neglected. Calculate the vapor pressure ...
Monday, April 15, 2013 at 11:33am

chemistry (electrochemistry)
1) For the following electrochemical cell Cu(s)|Cu2 (aq, 0.0155 M)||Ag (aq, 1.50 M)|Ag(s) write the net cell equation. Calculate the following values using standard potentials as needed. Eo cell and dGo for each reaction...................................
Monday, April 15, 2013 at 11:32am

chemistry
A current of 3.78 A is passed through a Pb(NO3)2 solution for 1.40 hours. How much lead is plated out of the solution?
Monday, April 15, 2013 at 9:53am

chemistry
how does an increase in pressure affect the following reaction? C2H2(g)+H2(g) C2H4(g)
Monday, April 15, 2013 at 9:39am

chemistry quick homework help
A gas occupies 359 mL at 501.4 Torr and 24.1 °C. When the pressure is changed to 441.8 Torr, what temperature is needed to maintain the same volume?
Monday, April 15, 2013 at 9:25am

Chemistry
Write the name and chemical formula of an amphoteric ion.
Monday, April 15, 2013 at 6:46am

chemistry
Name three sodium salts that produce weak bases in aqueous solution.
Monday, April 15, 2013 at 6:45am

chemistry university
A 179 mL solution of a copper complex with a molecular weight of 491.9 g mol-1 was made. The absorbance of the solution at 638 nm wavelength was 0.376 using a 1 cm cuvette. It is known that this copper complex has a molar absorptivity (extinction coefficient) of 324.4 M-1 cm-1...
Monday, April 15, 2013 at 4:45am

chemistry
What is the balanced formula for Solid iron 3 oxide reacts with hydrogen gas to form solid iron and liquid water?
Monday, April 15, 2013 at 1:41am

chemistry
An activation energy of 2.0 eV is required to form a vacancy in a metal. At 800¡èC there is one vacancy for every 10^-4 atoms. At what temperature will there be one vacancy for every 1000 atoms?
Monday, April 15, 2013 at 12:13am

Chemistry
only one of each of the following pairs of reactants undergoes a reaction. Complete and balance the equation for the reaction that occurs. NaCl (aq) + BaCl2 (aq) --> Na2SO4 (aq) + BaCl2 (aq) --> NO3^- (aq) + OH^- (aq)+ Al (s) --> CO3^2- (aq) + OH^- (aq) +Al (s) -->...
Monday, April 15, 2013 at 12:06am

chemistry
net ionic equations for Ca(NO3)2 +NaPO4
Monday, April 15, 2013 at 12:04am

chemistry
The question I am having trouble with is: Scientists originally were uncertain whether the oxygen gas produced during photosynthesis came from CO2, H2O, or from both. How could radioisotope tracers be used to settle that question? Chemistry - DrBob222 6CO2 + 6H2O ==> ...
Monday, April 15, 2013 at 12:04am

Chemistry
The question I am having trouble with is: Scientists originally were uncertain whether the oxygen gas produced during photosynthesis came from CO2, H2O, or from both. How could radioisotope tracers be used to settle that question?
Sunday, April 14, 2013 at 11:52pm

Chemistry
If the pressure is 10.0 atm, what is the temperature? If a 2.53-L container is filled with 169 g argon
Sunday, April 14, 2013 at 11:50pm

Chemistry
If the Kb of a weak base is 1.5 × 10^-6, what is the pH of a 0.25 M solution of this base? I found that I need to use the quadratic equation but I'm having difficulties because I come up with taking the square root by zero and that isn't right. Please help! a=1, ...
Sunday, April 14, 2013 at 11:46pm

Chemistry
What volume of H2(g), stored at 26°C at a pressure of 141 atm, would be needed to run an electric motor drawing a current of 8.4 A for 4.8 h?
Sunday, April 14, 2013 at 10:04pm

chemistry
Write the equations describing the electrode reactions and the net cell reaction for this electrochemical cell containing indium and cadmium: This is what I have so far: anode: In(s) --> In^3+ + 3e- cathode: Cd^2+ + 2e- --> Cd (s) Need help writing the balanced net ...
Sunday, April 14, 2013 at 9:51pm

Chemistry #2
If 100.0 g of water at 90'C is added to 50.0 g of water at 10'C, estimate the final temperature of the water. explain your reasoning. please my last question i really dont get it, :/
Sunday, April 14, 2013 at 9:31pm

Chemistry
In which case is heat involved: mixing 100.0-g samples of 90'C water and 80'C water or mixing 100.0-g samples of 60'C water? assume no heat is lost to the environment. please help thanks.
Sunday, April 14, 2013 at 9:29pm

chemistry
A voltaic cell that uses the reaction Tl3+(aq) + 2 Cr2+(s) ¨ Tl+(aq) + 2 Cr3+(aq) has a measured standard cell potential of +1.19 V. determine E‹red for the reduction of Tl3+(aq) to Tl+(aq).
Sunday, April 14, 2013 at 8:48pm

Chemistry
* Fixed Question What is the PH of a buffer made by adding 8.20 grams of sodium acetate(NaCH3CO2) to 500 ml of 0.10 M(molarity) acetic acid(CH3CO2H). Ka for acetic acid is 1.8 x 10^-5.
Sunday, April 14, 2013 at 8:24pm

Chemistry
What volume of 0.105 M(molarity)is needed to completely neutralize 25.0 ml of 0.180 M(molarity)HBr according to the equation: KOH(aq)+ HBr(aq)-> KBr(Aq)+ H2O(L)
Sunday, April 14, 2013 at 8:22pm

Chemistry
What is the PH of a buffer made by adding 8.20 grams of sodium acetate(NaCH3CO2) to 500 ml of 0.10 M acetic acid(CH3CO2H). Ka for acetic acid is 1.8 x 10^-5.
Sunday, April 14, 2013 at 8:17pm

Chemistry
radioactive sodium chloride is appropriate for diagnosing circulatory problems, but radioactive xenon is helpful in searching for lung problems. Explain why. I understand different elements are used for specific parts of the body but I don't understand this question. ...
Sunday, April 14, 2013 at 8:06pm

chemistry
hey guys please help me answer these questions. 1. can a strong acid be diluted. explain in detail 2. can a weak acid be diluted. explain in detail 3. how does your observation of sunlight change when you place two different concentrations of food colored solution over the ...
Sunday, April 14, 2013 at 6:18pm

Chemistry
I'm having a little trouble determining oxidation numbers for elements in a redox reaction KMnO4+HCl--> MnCl2+Cl2+H2O+KCl So far what I have for the reactants side is: K= +1 Mn= +7 O4= -2 H= +1 Cl= -1 And for the products side I have: Mn= +2 Cl2= -1 Cl2(diatomic)= 0 H2...
Sunday, April 14, 2013 at 3:36pm

Chemistry
What is the hydronium ion concentration in a solution 0.150M in HNO2 and 0.300M in NaNO2? Ka = 7.24E-4
Sunday, April 14, 2013 at 2:32pm

chemistry
The escape velocity from earth is 2.5 x10^4 miles per hour. What is this speed in m/s? (1 mile 1609 m)
Sunday, April 14, 2013 at 1:55pm

Chemistry
how to find the mass of the substance if the only given is the molar mass???
Sunday, April 14, 2013 at 1:11pm

Quantum/inorganic chemistry
c. Which of these electron configurations has the 4F term symbol for its ground state? p3 d3 d4 f2 f3
Sunday, April 14, 2013 at 11:23am

Chemistry
Calculate the pH of a buffer solution that contains 0.60 M NaH2PO4, and 0.26 M Na2HPO4.
Sunday, April 14, 2013 at 11:18am

chemistry
how do I carry out qualitative analysis on (NH4)2SO4.FESO4.6H20
Sunday, April 14, 2013 at 8:59am

chemistry
how would you solve the mass of sucrose, C12H22O11, that is needed to make 550ml of a 0.25M solution?
Sunday, April 14, 2013 at 12:54am

chemistry
When 25.0 g of Zn reacts,how many L of H2 are formed at STP?
Saturday, April 13, 2013 at 11:38pm

Chemistry
2Al(s) + 6H+(aq) → 2Al3+(aq) + 3H2(g) For the above Al-H2 cell, what is the voltage if [Al3+] = 6.0461 M, [H+] = 6.1 M, and the hydrogen pressure is 0.0557 atm. Eo = 1.66 V. .00004-(.05916/6)*log(7.1e-4) =.03 WRONG ANSWER I GOT .00004=(6.0461*6.0461*.0557)/(6.1^6) Can ...
Saturday, April 13, 2013 at 8:00pm

Chemistry
You have 500 mL of a 5.0 M solution of nitric acid HNO3 (63.01 g / mol) dissolved in water. How many grams of nitrogen does the solution contain?
Saturday, April 13, 2013 at 7:49pm

Chemistry
20.0 mL of HCl in a flask Titration required 12.3 mL of 0.108M Mg(OH)-2 What is the molarity of the HCl?
Saturday, April 13, 2013 at 5:40pm

Chemistry
A glass of composition 85% SiO2 - 15% K2O is to be surface strengthened by ion exchange. To this end, two identical specimens approximately the size and shape of credit cards are soaked for the same amount of time at 850∘C. Sample A is soaked in NaCl and sample B is ...
Saturday, April 13, 2013 at 3:59pm

Alan
Mark below all of the statments that correctly describe the physical properties of glass. Glasses do not have slip systems. Glasses consist of both covalent and ionic bonding. Glasses are brittle at room temperature. Glasses are amorphous and have no long range symmetry. The ...
Saturday, April 13, 2013 at 3:56pm

Chemistry
Why would HF have a lower electrical conductivity than NaCl?
Saturday, April 13, 2013 at 3:45pm

chemistry
how many atoms are present in a sample of water molecules with a mass of 1.800g
Saturday, April 13, 2013 at 3:01pm

Chemistry
Consider the equilibrium 2NOCl (g) <---> 2NO (g) + Cl2 (g). In a 1 L container @ equilibrium there are 1.0 mol NOCL, 0.70 mol NO, and 0.40 mol Cl2. @ constant temperature and volume, 0.10 mol NaCl is added. What are the concentrations in the "new" equilibrium ...
Saturday, April 13, 2013 at 2:52pm

Chemistry
Which of the following is/are present in a reagent bottle labeled 1.0 M H2SO4? I. H2SO4 II. HSO4- III. SO4-2 A. I only B. I and II C. II and III D. I, II, and III
Saturday, April 13, 2013 at 2:35pm

Chemistry
You titrate a 10.0 mL sample of phosphoric acid with a 1.65 M solution of the base potassium hydroxide. It takes 7.55 mL to reach the endpoint of the titration. What is the molar concentration of the original solution of phosphoric acid? 3KOH + H3PO4 --> K3PO4 + 3H2O
Saturday, April 13, 2013 at 12:32pm

physical chemistry
1000 ml of oxygen at ntp passed through siemens ozoniser when the resulting volume was 888 ml at ntp .quantity of ozonised oxygen is passed through excess of potassium iodide solution calculate weight of iodine liberated?
Saturday, April 13, 2013 at 7:13am

chemistry
A glass of composition 85% SiO2 - 15% K2O is to be surface strengthened by ion exchange. To this end, two identical specimens approximately the size and shape of credit cards are soaked for the same amount of time at 850 ∘C. Sample A is soaked in NaCl and sample B is ...
Saturday, April 13, 2013 at 5:48am

chemistry
Please mark below all of the statments that correctly describe the physical properties of glass. Glasses do not have slip systems. Glasses consist of both covalent and ionic bonding. Glasses are brittle at room temperature. Glasses are amorphous and have no long range symmetry...
Saturday, April 13, 2013 at 5:48am

chemistry
Which of the following statements describes why ion exchange of 99% SiO2 - 1% B2O3 in a salt bath of molten postassium chloride (KCl) is not an effective way to increase the surface strength of the glass sample? The ion exchange works correctly, however both air-cooling and ...
Saturday, April 13, 2013 at 5:46am

chemistry
In the following reaction, how many grams of ferrous sulfide (FeS) will produce 0.56 grams of iron (III) oxide (Fe2O3)? 4FeS + 7O2 d 2Fe2O3 + 4SO2 The molar mass of ferrous sulfide is 87.92 grams and that of iron (III) oxide is 159.7 grams.
Saturday, April 13, 2013 at 2:58am

Chemistry
Consider the equilibrium 2NO (g) <---> 2NO (g) + Cl2 (g). In a 1 L container @ equilibrium there are 1.0 mol NOCL, 0.70 mol NO, and 0.40 mol Cl2. @ constant temperature and volume, 0.10 mol NaCl is added. What are the concentrations in the "new" equilibrium in ...
Friday, April 12, 2013 at 11:22pm

chemistry
What is the difference between e/z notation and cis-trans isomerism?
Friday, April 12, 2013 at 9:43pm

chemistry
Please mark below all of the statments that correctly describe the physical properties of glass. Glasses do not have slip systems.Glasses consist of both covalent and ionic bonding.Glasses are brittle at room temperature.Glasses are amorphous and have no long range symmetry....
Friday, April 12, 2013 at 7:32pm

chemistry
Consider two glasses. Glass A has a composition of 5% CaO - 95% B2O3. Glass B has a composition of 15% CaO - 85% B2O3. Both samples are cooled from their molten state to room temperature at rates that result in an identical glass transition temperature. Given this information...
Friday, April 12, 2013 at 7:24pm

chemistry
Which of the following statements describes why ion exchange of 99% SiO2 - 1% B2O3 in a salt bath of molten postassium chloride (KCl) is not an effective way to increase the surface strength of the glass sample? a -The ion exchange works correctly, however both air-cooling and...
Friday, April 12, 2013 at 6:50pm

chemistry
A glass of composition 85% SiO2 - 15% K2O is to be surface strengthened by ion exchange. To this end, two identical specimens approximately the size and shape of credit cards are soaked for the same amount of time at 850degreeC. Sample A is soaked in NaCl and sample B is ...
Friday, April 12, 2013 at 6:36pm

chemistry
Which of these processes will lower the glass transition temperature of a glass? Increase the cooling rate, Decrease the cooling rate, Increase amount of network modifier, Decrease amount of network modifier, Quench the glass to cool the surfaces quickly, Decrease the number ...
Friday, April 12, 2013 at 6:16pm

chemistry
How many moles of sodium hydroxide are needed to react with 148.0 g of Iron (III) bromide?
Friday, April 12, 2013 at 1:21pm

Chemistry
The pH of an 0.0870 M solution of weak acid A is 2.20. The pH of an 0.0830 M solution of weak acid B is 4.07. The pH of an 0.0890 M solution of weak acid C is 5.13. Identify the three acids from among those listed below (the Ka values are listed in Appendix E of your textbook...
Friday, April 12, 2013 at 12:46pm

ap chemistry
The volume of 0.100 mol of helium gas at 34°C is increased isothermally from 1.00 L to 4.50 L. Assuming the gas to be ideal, calculate the entropy change for the process.
Friday, April 12, 2013 at 10:07am

College Chemistry
For each trial, enter the amount of heat lost by the calorimeter, qcalorimeter. Be careful of the algebraic sign here and remember that the change in temperature is equal to the final temperature minus the initial temperature. Report your answer using 4 digits. Note, this is 1...
Friday, April 12, 2013 at 5:39am

Chemistry
Calculate E°cell (in volts) for a fuel cell that employs the reaction between methane gas and oxygen to form carbon dioxide and water. (to 4 significant figures) ∆G⁰f for CH4 = -50.5 kJ/mol ∆G⁰f for CO2 = -394.4 kJ/mol F = 96485/mol e- I got 0.4455 ...
Friday, April 12, 2013 at 4:09am

chemistry
Monosodium glutamate (aka MSG) NaC5H8NO4 is used as a food additive for flavor or as a preservative. a. what is the mass of MSG (g) that contains 545 mg sodium? b. calculate the percentage of each element present in MSG.
Friday, April 12, 2013 at 2:25am

chemistry
A sample of hematite Fe2O3 has the mass 4.83 x 10 3 kg. a. how much iron (kg) can be extracted from this sample of hematite? b. what is the percentage of iron in this ore?
Friday, April 12, 2013 at 2:21am

chemistry
A student needs to use a 0.750 mol sample of (NH4)2SO3 for an experiment: a. how many grams does she need to weigh out? b. how many formula units are in the sample?
Friday, April 12, 2013 at 2:19am

Chemistry
Potassium hypobromite, KOBr, converts ammonia to nitrogen by the following reaction. 3KOBr + 2NH3 N2 + 3KBr + 3H2O To prepare 448.2 mL of dry N2, when measured at 22.3 °C and 777.3 torr, what is the minimum number of grams of KOBr required?
Friday, April 12, 2013 at 2:14am

Chemistry
How many grams of NaF should be added to 612 ml of 0.4 M HF (Ka = 6.8 x 10-4) to produce a buffer solution where pH = 3.10?
Friday, April 12, 2013 at 1:48am

Chemistry
An unknown amount of gas occupies 30.0 L at 2.1 atm and 298K. How many moles does the sample contain? What is the mass if the gas is helium? What is the mass if the gas is argon?
Friday, April 12, 2013 at 1:15am

Chemistry
If N2 is added to a balloon that contains O2 (partial pressure 450 mm Hg) and CO2 (partial pressure 150 mm Hg) to give a total pressure of 850 mm Hg, what is the partial pressure of each gas in the final mixture?
Friday, April 12, 2013 at 1:14am

Chemistry
Using the given boiling points, predict which compound has the higher vapor pressure at a given temperature. A. ethanol (C2H6O, bp 78 degrees C) or 1-propanol (C3H8O, bp 97 degrees C) B. hexane (C6H14, bp 69 degrees C) or octane (C8H18, bp 125 degrees C)
Friday, April 12, 2013 at 1:11am

Chemistry
A student in lab gathered temperature and concentration data for the solubility of borax and generated a plot of ln(Ksp) vs. 1/T having the equation of the line y = -11655x + 35.585. Determine the temperature (in units of K) at which the reaction becomes spontaneous.
Thursday, April 11, 2013 at 10:56pm

Chemistry
How much energy would be released when 675 grams of steam is condensed to water
Thursday, April 11, 2013 at 10:28pm

chemistry
I did an experiment today called "removing tarnish". we removed tarnish from a fork wrapped in foil paper. Now i have to answer some questions. please correct me if i answer them wrong. im not the best in chemistry. thanks. 1. describe the odor of the water trapped ...
Thursday, April 11, 2013 at 9:27pm

10th grade chemistry
How many grams of kno3 can be dissolved in 100g of h2o at 50°c
Thursday, April 11, 2013 at 8:46pm

Chemistry
The Ka of a monoprotic weak acid is 4.47 × 10-3. What is the percent ionization of a 0.184 M solution of this acid?
Thursday, April 11, 2013 at 8:36pm

Chemistry
A 10 mL sample of 1.5 M Potassium Phosphate is placed in a 100 mL volumetric flask and diluted to the mark. What is the Molar concentration of Potassium ions in this diluted solution?
Thursday, April 11, 2013 at 8:29pm

Chemistry
20.00mL of a 1.100E-4 mol/L Pb(NO3)2 is mixed with 80.00mL of 4.450E-2 mol/L CaI2. Will a precipitate form? Here's what I did... [Pb2+] c=n/v = (1.1E-4 mol/L x 0.02L)/(0.02L + 0.08L) = 2.2E-5 mol/L [I-] c=n/v = (4.45E-2 mol/L x 0.08L)/0.1L = 3.56E-2 mol/L Qsp = [Pb2+][I...
Thursday, April 11, 2013 at 6:41pm

Chemistry
I need help starting this question... A buffer solution is prepared by adding 30.0g of pure acetic acid to 41.0g of sodium acetate in water, and then diluting the solution to 1.00L. What is the pH of the buffer solution?
Thursday, April 11, 2013 at 6:29pm

chemistry
you heat 4.31 grams of a nickel 2 phosphate hydrate. You heat to a constant mass of 3.09 grams. What is the formula of this hydrate?
Thursday, April 11, 2013 at 5:46pm

Analytical Chemistry
A solution prepared by mixing 51.4 mL of 0.340 M AgNO3 and 51.4 mL of 0.340 M TlNO3 was titrated with 0.680 M NaBr in a cell containing a silver indicator electrode and a reference electrode of constant potential 0.175 V. The reference electrode is attached to the positive ...
Thursday, April 11, 2013 at 3:32pm

Chemistry
You extract the iron from a tablet and dilute that to 250.0 ml in a volumetric flask. You transfer 0.400 ml of this solution to a 25.0 ml volumetric flask and dilute this to volume. When you measure the concentration of this solution, you find that it is 3.27 ppm Fe. How many ...
Thursday, April 11, 2013 at 2:31pm

Chemistry
1. Which of the following compounds is an unsaturated hydrocarbon? methane *propyne nonane methyl 2. The general name for hydrocarbons with at least one triple covalent bond is ____. alkenes alkyls alkanes *alkynes 3. What is the name of the smallest alkyne? butyne *ethyne ...
Thursday, April 11, 2013 at 2:04pm

Chemistry: Please check answers
1. Which of the following compounds is an unsaturated hydrocarbon? methane *propyne nonane methyl 2. The general name for hydrocarbons with at least one triple covalent bond is ____. alkenes alkyls alkanes *alkynes 3. What is the name of the smallest alkyne? butyne *ethyne ...
Thursday, April 11, 2013 at 1:16pm

chemistry
A student estimated the volume of a liquid in a beaker to be 300 mL. When she poured the liquid into a graduated cylinder, she measured the volume as 295 mL. Considering the measurement in the graduated cylinder to be the accepted value, what is the percent error of the ...
Thursday, April 11, 2013 at 12:05pm

chemistry
Cathode = Cu2(s) + 2e- ¨ Cu(s) Anode = 2H2O(l) ¨ O2(g) + 4H(g) + 4e- Net = Cu2(s) + 2H2O(l) ¨ Cu(s) + O2(g) + 4H(g) the minimum voltage that must be supplied to electrolyze aqueous copper(II) sulfate
Thursday, April 11, 2013 at 11:42am

Chemistry
What is the formula for CoCl2 with 45.5 percent water?
Thursday, April 11, 2013 at 11:38am

Chemistry
How many grams of co2 are in 3.92 times 10 to the 24th molecules
Thursday, April 11, 2013 at 9:36am

Chemistry
How many milliliters water are needed to make a 0.171 M solution that contains 1.00 g of NaCl?
Thursday, April 11, 2013 at 7:55am

Chemistry
Which of these processes will lower the glass transition temperature of a glass? 1 - Increase the cooling rate 2 - Decrease the cooling rate 3 - Increase amount of network modifier 4 - Decrease amount of network modifier 5 - Quench the glass to cool the surfaces quickly 6 - ...
Thursday, April 11, 2013 at 5:46am

chemistry
Please i tried to give this answer on a quiz but it was not accepted. To name this alkane: CH3CH2CH2CHCH3 with a substituent of CH3 on 2nd carbon.
Thursday, April 11, 2013 at 1:05am

Chemistry
How many liters are in .005 moles?
Wednesday, April 10, 2013 at 11:23pm

Chemistry
How much energy in kilocalories is needed to vaporize 255g of water? The heat of vaporization of water is 540 cal/g.
Wednesday, April 10, 2013 at 11:14pm

Chemistry
What volume does 3.01 x 10^21 molecules of N2 occupy at STP?
Wednesday, April 10, 2013 at 11:06pm

chemistry
a salt shaker filled with 17.0g sodium chloride contain how many moles?
Wednesday, April 10, 2013 at 10:54pm

Chemistry 1301
How many g of NaOH are in 10 ml 0.1 M solution? How do you find this out, what are the steps?
Wednesday, April 10, 2013 at 8:58pm

Chemistry
Enough of a monoprotic acid is dissolved in water to produce a 1.47 M solution. The pH of the resulting solution is 2.64. Calculate the Ka for the acid.
Wednesday, April 10, 2013 at 8:54pm

Chemistry
Describe how you would prepare 2.00 L of an aqueous solution having a pH of 3.60 if you had a supply of 0.100 M HCL
Wednesday, April 10, 2013 at 8:24pm

chemistry
Sodium phosphate dodecahydate reacts with barium chloride dihydrate. If Na2SO4 is an unkown contaminant of sodium phosphate dodecahydrate, how does it presence affect yeild of sodium phosphate in the exexpiriment?
Wednesday, April 10, 2013 at 7:57pm

chemistry
Sodium phosphate dodecahydate is reacts with barium chloride dihydrate.barium phosphate is lost during filtering will the percent limiting reactant be hihg or low?
Wednesday, April 10, 2013 at 7:51pm

Chemistry
ph of a 0.234 m nahco3 solution look up the appropriate ka or kb value
Wednesday, April 10, 2013 at 7:35pm

Chemistry
The reaction for the formation of gaseous hydrogen fluoride from hydrogen and fluorine has an equilibrium constant of 1.15x10^2 at a given temperature. In a particular experiment, 3.0 mol of each component was added to a 1.5 L flask. What is the equilibrium concentration of ...
Wednesday, April 10, 2013 at 7:15pm

Chemistry
1.Write an equilibrium constant equation for the following reaction: 4NH3(g)+5O2(g)= 4NO(g)+6H2O(g) 2. What does the above [] mean in the above equation?
Wednesday, April 10, 2013 at 4:34pm

chemistry
calculate the solubility of SrSO4 in A: pure water B: 0.045 M Sr(NO3)2 C: 0.05 M NaCl D: 0.016 M ZnCl2
Wednesday, April 10, 2013 at 2:48pm

chemistry
nitrogen gas reacts with hydrogen gas to form ammonia. The nitrogen gas is in a closed 500.0 mL flask at 751 mm HG connected to a 1.25 L flask containing the hydrogen gas at 1.21 atm pressure. Both flasks are kept at 37C. if the stopcock is opened and the gases are allowed to ...
Wednesday, April 10, 2013 at 2:40pm

Chemistry
A buret is partially filled with NaOH solution, to a volume of 1.14 mL. A 20-mL sample of 0.1011 M HCl is titrated to a faint pink phenolphthalein endpoint. The final buret reading is 22.37 mL. What is the molartiy of the NaOH solution?
Wednesday, April 10, 2013 at 1:17pm

Chemistry
A gaseous mixture contains 436.0 Torr of H2(g), 341.5 Torr of N2(g), and 79.7 Torr of Ar(g). Calculate the mole fraction, X, of each of these gases.
Wednesday, April 10, 2013 at 12:12pm

chemistry
A solution of household bleach contains 5.25% sodium hypochlorite, NaOCl, by mass. Assuming that the density of bleach is the same as water, calculate the volume of household bleach that should be diluted with water to make 500.0 mL of a pH = 10.23 solution.
Wednesday, April 10, 2013 at 11:58am

chemistry
The Ka of a monoprotic weak acid is 7.25 × 10-3. What is the percent ionization of a 0.167 M solution of this acid? If the concentration is more than 1000 times greater than the Ka, then you can make an assumption that simplifies the algebra needed to solve the problem. ...
Wednesday, April 10, 2013 at 11:57am

chemistry
The half-equivalence point of a titration occurs half way to the end point, where half of the analyte has reacted to form its conjugate, and the other half still remains unreacted. If 0.460 moles of a monoprotic weak acid (Ka = 3.8 × 10-5) is titrated with NaOH, what is ...
Wednesday, April 10, 2013 at 11:55am

chemistry
A flask contains 0.342 g of acid and a few drops of phenolphthalein indicator dissolved in water. The buret contains 0.120 M NaOH. 20.f mL of base is needed to reach the endpoint of the titration. Assuming that the acid is monoprotic, what is the molar mass?
Wednesday, April 10, 2013 at 11:53am

chemistry
Which of these processes will lower the glass transition temperature of a glass? 1 - Increase the cooling rate 2 - Decrease the cooling rate 3 - Increase amount of network modifier 4 - Decrease amount of network modifier 5 - Quench the glass to cool the surfaces quickly 6 - ...
Wednesday, April 10, 2013 at 10:55am

Chemistry
What quantity of heat is required to flow into 1.50 g of water at 18.0 degrees Celsius that is heated in an electric kettle to 70.0 degrees Celsius?
Wednesday, April 10, 2013 at 10:21am

Chemistry
A glass of composition 85% SiO2 - 15% K2O is to be surface strengthened by ion exchange. To this end, two identical specimens approximately the size and shape of credit cards are soaked for the same amount of time at 850 ∘C. Sample A is soaked in NaCl and sample B is ...
Wednesday, April 10, 2013 at 10:06am

Chemistry
55 kJ of heat are added to 200 kg of a metal at 28.00◦C and the temperature rises to 29.18◦C. What was the metal? 1. tungsten (speciﬁc heat = 0.134 J/g · ◦ C) 2. copper (speciﬁc heat = 0.385 J/g · ◦ C) 3. silver (speciﬁ...
Wednesday, April 10, 2013 at 10:04am

Chemistry
Which of these processes will lower the glass transition temperature of a glass? 1.Increase the cooling rate 2.Decrease the cooling rate 3.Increase amount of network modifier 4.Decrease amount of network modifier 5.Quench the glass to cool the surfaces quickly 6.Decrease the ...
Wednesday, April 10, 2013 at 10:04am

chemistry
what is the mass of LiF is needed to produce 2.5 L of a .30 M solution
Wednesday, April 10, 2013 at 9:45am

chemistry
For reactions in solution, molar concentrations are usually used in equilibrium constant expressions (designated by K or Kc). In gases, partial pressures can also be used (designated by Kp). Equilibrium partial pressures of NOCl, NO and Cl2 in a container at 300 K are 1.2 atm...
Wednesday, April 10, 2013 at 9:31am

chemistry
Hydrogen iodide reacts with itself to give hydrogen and iodine. The equilibrium constant is about 2.0 x 10─3 at a particular temperature. If you were to place some hydrogen iodide in a container and seal the container, what would you expect to find at equilibrium: mostly...
Wednesday, April 10, 2013 at 9:30am

chemistry
Which of the following statements describes why ion exchange of 99% SiO2 - 1% B2O3 in a salt bath of molten postassium chloride (KCl) is not an effective way to increase the surface strength of the glass sample? a) The ion exchange works correctly, however both air-cooling and...
Wednesday, April 10, 2013 at 8:59am

chemistry
Which of these processes will lower the glass transition temperature of a glass? a) Increase the cooling rate b) Decrease the cooling rate c) Increase amount of network modifier d) Decrease amount of network modifier e) Quench the glass to cool the surfaces quickly f) Decrease...
Wednesday, April 10, 2013 at 8:52am

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