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September 1, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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chemistry
how many grams of sodium metal are needed to give 781 g of hydrogen?
Thursday, March 13, 2014 at 8:28am

Chemistry
The lattice enthalpies of NACL KCL and AGCL are 787,717 and 916 kj/mol; based on these values , arrange them in increasing order of water solubility and expain the answer.
Thursday, March 13, 2014 at 3:20am

Chemistry
The equilibrium constant Kc^i is 3.2x10^-34 at 25 degrees C for 2HCl(g) -> H2(g) + Cl2 (g). The equilibrium constant Kc^ii is .10 at 25 degrees C for 2ICl (g) -> Cl2 (g) + I2 (g). a) Calculate the equilibrium constant Kc for the reaction below at 25 C Cl2(g) + I2 (g) -&...
Thursday, March 13, 2014 at 2:37am

Chemistry 32
HCI (aq) is a strong acid. suppose you dissolved 0.0365 grams of HCI in water to give a final volume of 10.0 mL. what is the pH of this final solution. The molar mass of HCU is 36.5g /mole and the molar mass of water is 18.0g/mole
Wednesday, March 12, 2014 at 11:25pm

CHEMISTRY.
what would be the VSEPR shape of pyridine?
Wednesday, March 12, 2014 at 10:26pm

chemistry
1. How many different 4p orbitals are there? 2. How many radial nodes are there? 3. How many angular nodes are there? (excluding the radial nodes) I thought it was 2,1, 2??
Wednesday, March 12, 2014 at 9:53pm

chemistry
1. it takes: ____ electrons to fill the 6d subshell of an atom. 2. It takes _____ electrons to fill the n=6 shell of an atom. I thought it was 22 and 72?
Wednesday, March 12, 2014 at 9:26pm

chemistry
What is the velocity, in meters per second, of a beam of electrons if they are to display a "de Broglie" wavelength of 41.2 um?
Wednesday, March 12, 2014 at 9:24pm

chemistry
What is the longest wavelength of light that can be emitted by a hydrogen atom that has an initial configuration of 8p^1? Thank you!!
Wednesday, March 12, 2014 at 9:18pm

chemistry
What is (delta E) for the traansition of an electron from n=9 to n=4 in a Bohr hydrogen atom? What is the frequency? Thank you!
Wednesday, March 12, 2014 at 9:17pm

chemistry
What is the wavelength, in nm, of light with an energy content of (1.35x10^3 kJ/mol)? Thank you!!!
Wednesday, March 12, 2014 at 9:16pm

chemistry
Arrange the three metals in order of their relative strengths as reducing agents, placing the strongest first. Write each metal as a half reaction.
Wednesday, March 12, 2014 at 7:46pm

chemistry
what is the chemical reactions for these... 2Na+2H2O->2NaOH+H2 2FeS2+3O2->Fe2O2+2SO2 CaCO3->CO2+CaO
Wednesday, March 12, 2014 at 7:15pm

Chemistry
how do i name this chemical? S(ClO3)2
Wednesday, March 12, 2014 at 6:09pm

Chemistry
how do i name this chemical? Fe(NO3)2
Wednesday, March 12, 2014 at 5:24pm

Chemistry
If 6.51g of copper is reacted with 28.4g of silver nitrate, the products will be copper (II) nitrate and silver metal. What is the theoretical mass of silver that will be produced??
Wednesday, March 12, 2014 at 1:47pm

Chemistry
The reaction between 32.0g of CH4 and excess oxygen gas produces 75.9 of CO2 gas and some water. Determine the percent yield? Plss help :((
Wednesday, March 12, 2014 at 1:46pm

chemistry
Molality is a unit of concentration that measures the moles of solute per
Wednesday, March 12, 2014 at 1:26pm

STATISTIC HELP
1.M&M candies are great for probability. The following tables are the color distributions for the candies. Fill in each table with the missing probability and answer the questions that follow. Plain Brown Blue Green Orange Red Yellow Probability 0.3 0.1 0.1 0.1 0.02 ??? ...
Wednesday, March 12, 2014 at 1:08pm

Chemistry
If you dilute 11.6 mL of a 3.5 M solution to make 214.8 mL of solution, what is the molarity of the dilute solution?
Wednesday, March 12, 2014 at 12:28pm

Chemistry
What are the typical ppm values of hard water and an unknown water sample and how do their titrations compare?
Wednesday, March 12, 2014 at 3:13am

Chemistry
How would applying an external pressure on the following equilibrium affects the distribution of iodide between the polar (aqueous) and non polar (varsol) phases? I2+I^- --> I3^- All are aqueous solutions
Wednesday, March 12, 2014 at 1:33am

Chemistry
3. How does dissolved CO2 in distilled water affect the accuracy of the determination of a NaOH solution's concentration? The CO2 in the distilled water will create a more acidic solution which will affct the determination of NaOH solution's concentration? How is the ...
Tuesday, March 11, 2014 at 10:59pm

Chemistry
Determine the pH of a 1.2×10^−2 M solution
Tuesday, March 11, 2014 at 10:55pm

Chemistry
What is the pH of a solution whose [H3O+] is 9.2× 10^−9 M?
Tuesday, March 11, 2014 at 10:55pm

Chemistry Urgent
95.0mL of H2O is initially at room temperature (22.0∘C ). A chilled steel rod at 2.0∘C is placed in the water. If the final temperature of the system is 21.3∘C , what is the mass of the steel bar? Specific heat of water = 4.18 J/g⋅∘C Specific heat...
Tuesday, March 11, 2014 at 10:38pm

Chemistry Urgent
A calorimeter contains 32.0mL of water at 13.0∘C . When 2.30g of X (a substance with a molar mass of 82.0g/mol is added, it dissolves via the reaction X(s)+H2O(l)¨X(aq) and the temperature of the solution increases to 30.0∘C . Calculate the enthalpy ...
Tuesday, March 11, 2014 at 10:35pm

chemistry
95.0mLmL of H2O\rm H_2O is initially at room temperature (22.0∘C\rm{} ^{\circ}C). A chilled steel rod at 2.0∘C\rm ^{\circ}C is placed in the water. If the final temperature of the system is 21.3∘C^{\circ}C, what is the mass of the steel bar? Specific heat of ...
Tuesday, March 11, 2014 at 10:28pm

Chemistry
A solution contains 0.00245 M HCl. Determine the [H3O+] for the solution. points Determine the [OH-]
Tuesday, March 11, 2014 at 10:23pm

Chemistry
In neutralization reactions, acid + base ¨ salt + water HCl can be neutralized with NaOH. How many moles of NaOH will it take to neutralize 0.68 L of 0.29 M HCl? Is there a formula that I need to use here?
Tuesday, March 11, 2014 at 9:39pm

chemistry
A solution prepared by mixing 16.7 mL of 0.760 M NaCl and 16.7 mL of 0.760 M KI was titrated with 0.380 M AgNO3 in a cell containing a silver indicator electrode and a saturated calomel reference electrode. (a) What is [Ag+] when 16.2 mL of 0.380 M AgNO3 have been added? ...
Tuesday, March 11, 2014 at 9:30pm

Chemistry
You have a vinegar solution you believe to be 0.8 M. You are going to titrate 21.39 mL of it with a NaOH solution that you know to be 0.774 M. At what volume of added NaOH solution would you expect to see an end point? Answer in units of mL
Tuesday, March 11, 2014 at 9:07pm

Chemistry
At pH 3.85, which of the following is true? A.[lactic acid] > [lactate ion] B.[lactic acid] < [lactate ion] C.[lactic acid] = [lactate ion] At pH 11.61, which of the following is true? A.[lactic acid] = [lactate ion] B.[lactic acid] < [lactate ion] C.[lactic acid] &...
Tuesday, March 11, 2014 at 8:09pm

Chemistry
Sometimes the basicity of a solution is reported using pOH (pOH = -log[OH-]). What is the a. [OH-] if pOH = 1.90 b. [H3O+] if pOH = 12.94 c. pH if pOH = 9.70
Tuesday, March 11, 2014 at 7:30pm

Chemistry
Calculate the H3O+ concentration present in water under the following conditions. Enter your answer in scientific notation. [OH-] = 2.8 x 10-7 M [OH-] = 8.8 x 10-3 M [OH-] = 2.4 x 10-11 M
Tuesday, March 11, 2014 at 7:23pm

chemistry
i need help with writing nomenclature for the formula and the compounds examples: Sodium bisulphate hydroiodic acid ammonium dihydrogen phosphate Zn(HCrO4)2 Calcium metal ferrous bromide sodium carbide phosphate radical liquid mercury plumbic oxide auric carbonite sodium ...
Tuesday, March 11, 2014 at 6:57pm

Chemistry
A student walks at a brisk 3.50 mi/hr. Calculate the student's speed in yards/minute. I have 4 questions just like this one. Could you tell me step by step on how to do the double conversions? Thanks!
Tuesday, March 11, 2014 at 5:12pm

Chemistry check and help
what is ... Sodium bisulphate hydroiodic acid ammonium dihydrogen phosphate Zn(HCrO4)2 Calcium metal ferrous bromide sodium carbide phosphate radical Check... sodium bicarbonate NaHCO3
Tuesday, March 11, 2014 at 4:45pm

Chemistry
A 247 lb fullback runs the 40 yd dash at a speed of 17.09 ± 0.1 mi/h. (a) What is his de Broglie wavelength (in meters)? (b) What is the uncertainty in his position? ** I found part A but I am unsure how to use this information to get part B. Any help is appreciated :)
Tuesday, March 11, 2014 at 4:44pm

Chemistry
A student walks at a brisk 3.50 mi/hr. Calculate the student's speed in yards/minute. I have 4 questions just like this one. Could you tell me step by step on how to do the double conversions? Thanks!
Tuesday, March 11, 2014 at 4:41pm

chemistry
cuso4.5h20 + 2c2h5no2 = cu(gly)2.h20 moles of cuso4.5h2o produced is 12mmoles moles of glycine poriduced is 16.5 mmoles. which is the limiting reagent?
Tuesday, March 11, 2014 at 4:29pm

chemistry
A 125.0 mg sample of an unknown, monoprotic acid was dissolved in 100.0 mL of distilled water and titrated with a 0.050 M solution of NaOH. The pH of the solution was monitored throughout the titration, and the following data were collected. Determine the Ka of the acid. ...
Tuesday, March 11, 2014 at 3:22pm

Statistic Please Check
Check this out please Thanks Lesson 3 Unit 2 Probability Couplements, Disjoint Events and the addition Rule 1.M&M candies are great for probability. The following tables are the color distributions for the candies. Fill in each table with the missing probability and answer the...
Tuesday, March 11, 2014 at 11:44am

chemistry
In the laboratory a student finds that it takes 20.7 Joules to increase the temperature of 11.0 grams of solid platinum from 20.5 to 35.8 degrees Celsius. What is the specific heat of platinum she has measured.
Tuesday, March 11, 2014 at 11:36am

Chemistry
How do I balance the following reaction in acidic conditions? N2O4 + S8 = NO + H2SO3????
Tuesday, March 11, 2014 at 11:35am

Chemistry: Freezing point depression
What is the free sing point of a solution of ethyl alchohol, that contains 24g of the solute (C2H5OH), dissolved in 780 g of water
Tuesday, March 11, 2014 at 9:50am

chemistry
How many grams of calcium carbonate are required to prepare 50.0 grams of calcium oxide? CaCO3-> CaO + CO2
Tuesday, March 11, 2014 at 8:19am

chemistry
Titration was used to determine the molarity of acetic acid in vinegar. A primary standard solution of KHP was used to standardize the NaOH. 1. When performing this experiment, impure KHP was used to standardize the NaOH solution. If the impurity is neither acidic or basic, ...
Tuesday, March 11, 2014 at 2:25am

Chemistry
How many moles of sulfur are present in 2.6 moles of Al2(SO4)3?
Monday, March 10, 2014 at 10:29pm

AP Chemistry
1,2-Benzanthracene is a yellow-brown nonvolatile solid with molecular weight 228.29g*mol-1. an 18.2632-g sample of 1,2-benzanthracene is dissolved in 250.0 g of benzene, C6H6. Whta is the vapor pressure of this solution at 25C, in millimeters of mergury, if the vapor pressure ...
Monday, March 10, 2014 at 7:10pm

Chemistry ASAP
If 3.2 moles of NaCl are dissolved in enough water to make a 0.98-liter solution, what is the molarity of the solution?
Monday, March 10, 2014 at 5:35pm

chemistry
what volume of 1.5mols of tetraoxosulphate (iv) is needed to react with 2grams of calcium
Monday, March 10, 2014 at 5:32pm

chemistry
Phosphoric acid is a triprotic acid, so H3PO4, H2PO4 -, and HPO4 2- are all acids. Which of the solutions below would have the lowest pH? 0.1 M NaH2PO4 0.1 M Na2HPO4 0.1 M Na3PO4
Monday, March 10, 2014 at 3:12pm

Chemistry
Predict the standard cell potential and calculate the standard reaction Gibbs free energy for galvanic cells having the following cell reactions: 2H2+O2=2H2O in acidic solution 2H2+O2=2H2O in basic solution I understand the idea behind the problem, but I am not sure how the ...
Monday, March 10, 2014 at 1:52pm

Chemistry
A 108 mL gas sample has a mass of 77.96 mg at a pressure of 1140 mmHg and a temperature of 183 °C. Assume ideal gas behavior and a completely insulated system, and please don’t forget units with your answers. The system is cooled. Calculate the ...
Monday, March 10, 2014 at 11:30am

chemistry
0.05naoh in 2and half ml naoh?
Monday, March 10, 2014 at 5:16am

Chemistry
In a coffee cup calorimeter, 1.60 g of NH4NO3 is mixed with 75.0 g water at an initial temperature of 23.50 ºC. When the salt was completely dissolved, the solution temperature of the calorimeter became 21.80 ºC. Assume the solution’s specific heat capacity is 4...
Monday, March 10, 2014 at 2:45am

Chemistry Urgent
Calculate the DHof for the following reaction under standard state conditions: 2 Ag2S(s) + 2 H2O(l) ---> 4 Ag(s) + 2 H2S(g) + O2(g) Given the following information: Ag2S(s) ÄHof = -32.6 kJ/mol H2O(l) Ä Hof = -285.83 kJ/mol H2S(g) ÄHof = -20.6 kJ/mol
Sunday, March 9, 2014 at 10:30pm

Chemistry Urgent
Consider the following problem: Target: 2NOCl(g) ? N2(g)+ O2(g)+Cl2 (g) ?Hrxn= ? Steps: 1. 1/2 N2(g) + 1/2 O2(g)? NO(g) ?H= 90.3 kJ 2. NO(g) + 1/2 Cl2(g) ? NOCl(g) ?H= -38.6 kJ As you determine the ¥ÄHrxn value for the target equation above, what must be done to step ...
Sunday, March 9, 2014 at 10:28pm

chemistry
what is the latent heat of silver metal if 55.0 grams of metal liquefies with 47.3J of heat added?
Sunday, March 9, 2014 at 10:28pm

Chemistry
Potassium permanganate (KMnO4) solutions are used for the determination of iron in samples of unknown concentration. As a laboratory assistant, you are supposed to prepare 700. mL of a 0.200 M KMnO4 solution. What mass of KMnO4, in grams, do you need?
Sunday, March 9, 2014 at 10:21pm

Chemistry Urgent
Assuming that kerosene is C11H24, calculate the standard enthalpy change when 1 mole of kerosene burns completely in oxygen, using the data below: ΔH of formation of C11H24(l) = -327 kJ mol ΔH of formation of CO2(g)= -394 kJ mol ΔH of formation of H2O (l)= -286 ...
Sunday, March 9, 2014 at 10:17pm

Chemistry
How would applying an external pressure on the following equilibrium affects the distribution of iodide between the polar (aqueous) and non polar (varsol) phases? I2+I^- --> I3^-
Sunday, March 9, 2014 at 8:03pm

Chemistry
A mixture of NaCN and NaHSO4 consists of a total of 0.60 mol. When the mixture is dissolved in 1.0 L of water and comes to equilibrium the pH is found to be 9.7.
Sunday, March 9, 2014 at 7:08pm

Chemistry
The pressure on a gas at -58 degrees Celcius is doubled, but its volume is held constant. What will the final temperature be in degrees Celsius?
Sunday, March 9, 2014 at 4:08pm

Chemistry
Before a trip from New York to Boston, the pressure in the automobile tire is 2.1 atm at 280 K. At the end of the trip, the pressure gauge reads 1.88 atm. What is the new Celsius temperature of the air inside the tire?(Assume tires with constant volume). This is how I did it: ...
Sunday, March 9, 2014 at 3:37pm

Chemistry
Consider the following problem: Target: 2NOCl(g) ? N2(g)+ O2(g)+Cl2 (g) ?Hrxn= ? Steps: 1. 1/2 N2(g) + 1/2 O2(g)? NO(g) ?H= 90.3 kJ 2. NO(g) + 1/2 Cl2(g) ? NOCl(g) ?H= -38.6 kJ As you determine the ¥ÄHrxn value for the target equation above, what must be done to step ...
Sunday, March 9, 2014 at 3:30pm

chemistry
A sample of hydrogen at 50◦C exerts a pressure of 0.377 atm. The gas is heated to 61◦C at constant volume. What will its new pressure be? how do i find the pressure? i dont understand!!!!!!!!!!!
Sunday, March 9, 2014 at 3:15pm

chemistry
Calculate the DHof for the following reaction under standard state conditions: 2 Ag2S(s) + 2 H2O(l) ---> 4 Ag(s) + 2 H2S(g) + O2(g) Given the following information: Ag2S(s) ÄHof = -32.6 kJ/mol H2O(l) Ä Hof = -285.83 kJ/mol H2S(g) ÄHof = -20.6 kJ/mol
Sunday, March 9, 2014 at 3:10pm

chemistry
Consider the following problem: Target: 2NOCl (g) ¡æ N2 (g) + O2 (g) + Cl2 (g) ¥ÄHrxn= ? Steps: 1. ¨ö N2(g) + ¨ö O2(g) ¡æ NO(g) ¥ÄH= 90.3 kJ 2. NO(g) + ¨ö Cl2(g) ¡æ NOCl(g) ¥Ä H= -38.6 kJ...
Sunday, March 9, 2014 at 3:07pm

Chemistry
How would you precipitate BaCrO4 from a solution of Ba(NO3)2 and K2CrO7?
Sunday, March 9, 2014 at 3:07pm

chemistry
7.00 grams of sugar (C12H22O11) are dissolved in water to make 1 L of solution. What is the concentration of this solution? Answer in units of M
Sunday, March 9, 2014 at 2:56pm

chemistry
The equilibrium constant, Kp, for the following reaction is 2.74 at 1150 K. Calculate Kc for this reaction at this temperature. 2SO3(g) 2SO2(g) + O2(g)
Sunday, March 9, 2014 at 2:52pm

Chemistry - Le Chatelier's Principle
Hi, I have a question regarding the following chemical equilibrium equation: 2CrO4^2- + 2H3O^+ <--> Cr2O7^2- + 3H2O The question is: how would you manipulate the above equation to produce more Cr2O7^2- ions without adding any Chromium based compounds? I understand the ...
Sunday, March 9, 2014 at 1:30pm

Chemistry
what would the product be of HNO3 is heated
Sunday, March 9, 2014 at 1:19pm

chemistry
A sample of gas has a mass of 0.565g . Its volume is 120 mL at a temperature of 80∘C and a pressure of 747 mmHg . what is the molar mass
Sunday, March 9, 2014 at 11:24am

Chemistry
Consider the following problem: Target: 2NOCl (g) ¡æ N2 (g) + O2 (g) + Cl2 (g) ¥ÄHrxn= ? Steps: 1. ¨ö N2(g) + ¨ö O2(g) ¡æ NO(g) ¥ÄH= 90.3 kJ 2. NO(g) + ¨ö Cl2(g) ¡æ NOCl(g) ¥Ä H= -38.6 ...
Sunday, March 9, 2014 at 9:57am

chemistry
Calculate the DHof for the following reaction under standard state conditions: 2 Ag2S(s) + 2 H2O(l) ---> 4 Ag(s) + 2 H2S(g) + O2(g) Given the following information: Ag2S(s) ÄHof = -32.6 kJ/mol H2O(l) Ä Hof = -285.83 kJ/mol H2S(g) ÄHof = -20.6 kJ/mol Question...
Sunday, March 9, 2014 at 9:51am

Chemistry
What is the freezing point of a solution prepared by adding 264g of copper(ii) sulfate to 4 liters of water? The freezing point constant of water is 1.86°C/m.
Sunday, March 9, 2014 at 12:01am

chemistry
75.0 g of H2O at 23.0 oC is added to 100.0 g of H2O at 67.5 oC. What is the temperature of the resulting mixture?
Saturday, March 8, 2014 at 11:25pm

chemistry
Consider the following chemical reaction: 2H2O2(L) ¨ 2H2O(L) + O2(g) ƒ¢Hrxn = -196.1 kJ How much heat is released if 2 moles of O2 are produced?
Saturday, March 8, 2014 at 11:24pm

chemistry
Consider the following problem: Target: 2NOCl (g) ¡æ N2 (g) + O2 (g) + Cl2 (g) ¥ÄHrxn= ? Steps: 1. ¨ö N2(g) + ¨ö O2(g) ¡æ NO(g) ¥ÄH= 90.3 kJ 2. NO(g) + ¨ö Cl2(g) ¡æ NOCl(g) ¥Ä H= -38.6 kJ...
Saturday, March 8, 2014 at 11:23pm

chemistry
Which of the following pairs are both exothermic processes? Question options: a. Evaporation/melting b. Evaporation/freezing c. Condensation/melting d. Condensation/freezing
Saturday, March 8, 2014 at 11:21pm

chemistry
Calculate the DHof for the following reaction under standard state conditions: 2 Ag2S(s) + 2 H2O(l) ---> 4 Ag(s) + 2 H2S(g) + O2(g) Given the following information: Ag2S(s) ÄHof = -32.6 kJ/mol H2O(l) Ä Hof = -285.83 kJ/mol H2S(g) ÄHof = -20.6 kJ/mol
Saturday, March 8, 2014 at 11:19pm

chemistry
What mass of bromine gas will form from the complete reaction of 150 g potassium bromide and 120 g of chlorine
Saturday, March 8, 2014 at 7:57pm

chemistry
How much 6.0M NaoH must be added to 0.5L of a buffer that is 0.0200M acetic acid and 0.0250M sodium acetate to raise the PH to 5.75
Saturday, March 8, 2014 at 5:50pm

general chemistry
How much 6.0M NaoH must be added to 0.5L of a buffer that is 0.0200M acetic acid and 0.0250M sodium acetate to raise the PH to 5.75
Saturday, March 8, 2014 at 3:47pm

chemistry
A student stated that the solubility of KCl at 20 degrees Celsius was 36 grams of KCl per 100 grams of solution. What is wrong with this statement?
Saturday, March 8, 2014 at 2:05pm

chemistry
A student stated that the solubility of KCL, at 20 degrees Celsius was 36 grams of KCL per 100 grams of solution. What is wrong with this statement?
Saturday, March 8, 2014 at 2:03pm

chemistry
A student is working on a research project. The instructions in the book on how to prepare Ni(NH3)6Cl2 say that the percent yield in this preparation is 75.5 %. If the limiting reagent for the preparation is NiCl2·6H2O, and the student needs 50.0 grams of the Ni(NH3)...
Saturday, March 8, 2014 at 5:08am

CHEMISTRY
Consider the reaction N2+O2-->2NO with Delta H=43.2kcal. When 50.0g of N2 react with an excess of oxygen, how much heat is generated/consumed? I know that this is an endothermic reaction b/c of the + delta H, is there some sort of formula to use here? I have no idea where ...
Saturday, March 8, 2014 at 1:47am

Chemistry
1.600g of a metallic oxide of type MO were dissolved in100mL 1.0M HCl. The resulting liquid was made up to 500mL with distilled water. 25.00mL of the solution ,then required 21.02mL of 0.1020 M of NaOH for neutralization. Calculate the mass of the oxide combining with 1 mole ...
Friday, March 7, 2014 at 11:36pm

Chemistry
2 NO(g) + O2 (g) <==> 2 NO2 (g) Given that Kp=7.96×1012 for the reaction above and the following starting conditions: Initial Concentrations p(NO)=0.775 atm p(NO2)=0.000 atm p(O2)=0.789 atm Determine the equilibrium concentration of NO2.
Friday, March 7, 2014 at 10:59pm

chemistry
Hey Guys so I have this problem with ICE tables that is extremely confusing for me so I would love some help on it! At a Certain Temperature, the equilibrium constant for the reaction of NO with Cl2 is 6250. If the initial concentration of NOCl is 1.0M and that of NO 0.10M ...
Friday, March 7, 2014 at 8:09pm

chemistry
Given the following sets of values for three of the gas variables, calculate the unknown. P = ? mm Hg; V = 26.0 mL; n = 0.007826 mol; T = 15.6°C
Friday, March 7, 2014 at 6:41pm

chemistry
If a gaseous mixture is made of 2.37 g of He and 2.73 g of Ne in an evacuated 1.19 L container at 25°C, what will be the partial pressure of each gas and the total pressure in the container?
Friday, March 7, 2014 at 6:14pm

College Chemistry
Please help me. I have worked on this for 2 days. I don't understand the ratio of this equation.4Na+O2 to 2Na2O. for question: How many grams of Na2O are produced when 81.ograms of Na reacts?
Friday, March 7, 2014 at 4:59pm

CHEMISTRY
When 6.724 g of one of the hydrates of sodium sulfate (Na2SO4) was heated to drive off its water of hydration, the residue of anhydrous sodium sulfate has a mass of 2.964 g. What is the value of x in the formula for the hydrate, Na2SO4•xH2O?
Friday, March 7, 2014 at 9:50am

CHEMISTRY
A lawn fertilizer is rated as 6.50% nitrogen, meaning 6.50 g of N in 100 g of fertilizer. The nitrogen is present in the form of urea, (NH2)2CO. How many grams of urea are present in 100 g of the fertilizer to supply the rated amount of nitrogen?
Friday, March 7, 2014 at 9:49am

Chemistry
A 2.6 g of a substance that looks like gold needed 9.4 J of heat energy to raise its temperature from 20 to 38 ºC. Is the metal pure gold?
Friday, March 7, 2014 at 4:11am

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