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September 2, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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chemistry
A sample of solid monoprotic acid with molar mass equal to 169.7 g/mol was titrated with 0.1599M sodium hydroxide solution. Calculate the mass in grms fo acid to be used if the volume of NAOH to be used is 25ml. My calculation 0.1599 x 0.025L = 0.00399 0.00399 x 1000 = 3.9975 ...
Saturday, August 4, 2012 at 2:41pm

chemistry
How many moles of chloride ions are present in 18.4g of CaCl2? I don't know how to set this up...
Saturday, August 4, 2012 at 8:28am

chemistry
Ethanol (C2H6O) is combusted with oxygen to produce carbon dioxide and wateraccording to the following reaction: C2H6O + 3O2 -----> 2H2O + 3CO2 If 50g of ethanol is combusted, determine the volume of carbon dioxide that will be produced if the temperature is 25oC and the ...
Friday, August 3, 2012 at 9:45pm

Chemistry
The enthalpy of combustion of benzoic acid(C6H5COOH) which is often used to calibratecalorimeters, is −3227 kJ/mol. When 1.316 gof benzoic acid was burned in a calorimeter, the temperature increased by 2.226◦C. What is the overall heat capacity of the calorimeter? ...
Friday, August 3, 2012 at 5:23pm

chemistry
I posted this question last night but did not get an answer- I am posting again because I have an exam I am studying for and do not understand this concept! Thanks! Using the given data, and the table of Standard Reduction Potentials, find the standard reduction potential for ...
Friday, August 3, 2012 at 2:34pm

Chemistry 2
Supposed you stoppered the flasks after your titration to determine the equilibrium constant and kept the solutions for another day so that the equilibrium was re-established. What would happen to the amount of ethanol present? What would be the relationship of the original ...
Friday, August 3, 2012 at 12:42pm

Chemistry
Find the equilibrium moles for the following reaction with initially 0.051 mol for Ethyl acetate, 0.260 mol for water and 0.03045 mol of acetic acid at equilibrium. I'm not sure how to get the ones at equilibrium for the left side or even how much you have to take away for...
Friday, August 3, 2012 at 11:56am

chemistry
Using the given data, and the table of Standard Reduction Potentials, find the standard reduction potential for this half reaction: 8H^+ + BaCrO4(s) + 3e- -> Ba^2+ + Cr^3+ + 4H2O(l) given: Ksp (BaCrO4)=2.1E-10 DeltaGf* (kJ/mol): CrO4^2- (-727.75), Cr2O7^2- (-1301.1), H+ (0...
Thursday, August 2, 2012 at 10:30pm

chemistry
why did the solution turn to pink at the end of the titration ?
Thursday, August 2, 2012 at 9:56pm

chemistry
determine the concentration of Fe2+ ion the prepared solution
Thursday, August 2, 2012 at 9:54pm

chemistry
determine the number of moles of FeSO4 in sample Y that you use
Thursday, August 2, 2012 at 9:51pm

chemistry
determine the mass of FeSO4 in sample Y that you use
Thursday, August 2, 2012 at 9:50pm

chemistry
calculate the percentage of FeSO4 in sample Y
Thursday, August 2, 2012 at 9:44pm

CHemistry- For Dr.Bob
Hey Dr.Bob, I asked two days ago a question about a titration lab I had that you answered, but I still have one more question about that lab. Here's the lab summary: For my chemistry of solutions class, we had a titration lab where we titrated NaOH into an HCl + H2O mix. ...
Thursday, August 2, 2012 at 6:01pm

chemistry
Find the number of disintegrations per minute emitted by 1.1 mol of 232-Th in 1 min. The half-life of 232-Th is 1.4 x 1010 year I was able to do this with the following technique: 1.1 x 6.022 x10^23 =6.62x10^23 1.4x10^10=7.358x10^15 minutes I think then it is 6.62x10^23 x 7....
Thursday, August 2, 2012 at 1:18pm

chemistry
Calculate the following quantities. (See the periodic table.) (a) mass, in grams, of 2.54 10-2 mol of CdS g (b) number of moles of NH4Cl in 90.0 g of this substance mol (c) number of molecules in 5.081 10-2 mol C6H6 molecules (d) number of O atoms in 4.72 10-3 mol Al(NO3)3
Thursday, August 2, 2012 at 12:17am

organic chemistry
Describe and explain how each of the following experimental errors or variations might affect your results. (a) you failed to dry the reaction flask after washing it with water. (b) you forgot to add the sulfuric acid. (c) you used twice the amount of acetic acid specified in ...
Wednesday, August 1, 2012 at 9:57pm

CHEMISTRY
. For which reaction is ƒ´Ssys ƒ® 0? A) CH4(g) + 2 O2(g) ¡÷ CO2(g) + 2 H2O(l) B) NH3(g) + HCl(g) ¡÷ NH4Cl(s) C) 2 NH4NO3(s) ¡÷ 2 N2(g) + O2(g) + 4 H2O(g) D) HCl(aq) + NaOH(aq) ¡÷ NaCl(aq) + H2O(l)
Wednesday, August 1, 2012 at 7:15pm

CHEMISTRY
14. Calculate ƒ´S0 for the formation of 1 mol of HI(g) from its elements given the following information: S0[H2(g)] = 131 J/mol∙K S0[I2(s)] = 116 J/mol∙K S0[HI(g)] = 206 J/mol∙K. A) 82 J/K B) 165 J/K C) 247 J/K D) 329 J/K
Wednesday, August 1, 2012 at 7:14pm

CHEMISTRY
The standard molar entropy of lead(II) bromide (PbBr2) is 161 J/mol • K. What is the entropy of 2.45 g of PbBr2? a. +1.07 J/K d. –161 J/K b. –1.07 J/K e. 0 J/K c. +161 J/K
Wednesday, August 1, 2012 at 7:14pm

CHEMISTRY
The entropy of a NaCl crystal is __________ a. an intensive property and a state function. b. an intensive property and a path function. c. an extensive property and a state function. d. an extensive property and a path function. e. not appropriately described in terms of an ...
Wednesday, August 1, 2012 at 7:13pm

CHEMISTRY
During a spontaneous chemical reaction, it is found that äSsys < 0. This means __________ a. äSsurr < 0 and its magnitude is < äSsys. b. äSsurr < 0 and its magnitude is > äSsys. c. äSsurr > 0 and its magnitude is < äSsys...
Wednesday, August 1, 2012 at 7:12pm

CHEMISTRY
If 1 mol of ice melts at its melting point of 273 K, the entropy change for the ice is 22.0 J/K. If the ice melts in someone’s hand at 34°C, what is the change in the entropy of the universe? Assume a final temperature for the water of 0°C. The enthalpy of fusion ...
Wednesday, August 1, 2012 at 7:12pm

CHEMISTRY
What is the entropy change to the surroundings when 1 mol of ice melts in someone’s hand if the hand temperature is 32°C? Assume a final temperature for the water of 0°C. The heat of fusion of ice is 6.01 kJ/mol. a. –188 J/K d. +19.7 J/K b. –22.0 J/K e...
Wednesday, August 1, 2012 at 7:12pm

Chemistry
Need help to identify 10 facts about the reaction that can be read in this equation: 2AgNO3 (aq) + PbBr2 (s) --> 2AgBr (s) + Pb(NO3) 2 (aq) I had already balanced the equation original was AgNO3 (aq) + PbBr2 (s) --> AgBr (s)+ Pb(NO3) 2 (aq)
Wednesday, August 1, 2012 at 4:18pm

chemistry
If you assume that there is 5% acetic acid in vinegar, how much vinegar should you weigh out so that the endpoint requires 25.0 mL of 0.186 M NaOH?
Wednesday, August 1, 2012 at 10:23am

chemistry
A volume of 40.0 of aqueous potassium hydroxide was titrated against a standard solution of sulfuric acid h2so4. What was the molarity of the solution if 20.02 of 1.50M h2s04 was needed? Who helps me to solve it for me.
Tuesday, July 31, 2012 at 11:44pm

chemistry
the equation n2+3h2 2nh3
Tuesday, July 31, 2012 at 9:27pm

Chemistry
Calculate the mole fraction of glucose (C6H12O6) in a solution which contains 15g of glucose in 100 g of H2O.
Tuesday, July 31, 2012 at 9:14pm

Chemistry
For the reaction IO3– + 5I– + 6H+ 3I2 + 3H2O the rate of disappearance of I– at a particular time and concentration is 2.8 x 10-3 M s-1. What is the rate of appearance of I2 in molarity per second?
Tuesday, July 31, 2012 at 8:34pm

Chemistry
A buffer is prepared by transferring equal concentrations of the components of the conjugate pair, C6H5COOH and C6H5COONa, into a beaker. What is the approximate pH of the buffer? (Ka = 6.5  10–5) a) 2.81 b) 4.19 c) 7.00 d) 9.81 e) 11.19
Tuesday, July 31, 2012 at 3:34pm

Chemistry - titration lab
Hello. For my chemistry of solutions class, we had a titration lab where we titrated NaOH into an HCl + H2O mix. This was a preparatory titration for the next one consisting of the hydrolysis of ethyl acetate into acetic acid with H+ ions as a catalyst (in our case the HCl). ...
Tuesday, July 31, 2012 at 11:42am

Chemistry
To make some solution 500mL H2SO4 0.3 M. How many grams of H2SO4 are used?
Tuesday, July 31, 2012 at 5:16am

chemistry
if the pressure of 1.50L of hydrogen gas at 100 degrees celsius decreases from .500atm to .115atm,what is the final volume. assume temp remains the same
Tuesday, July 31, 2012 at 2:07am

Chemistry
Which of the following is an oxidation-reduction (redox) reaction? A. 2K(s) + 2H2O(l) → 2KOH(aq) + H2(g) B. 2NaN3(g) → 2Na(g) + 3N2(g) C. 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g) D. Fe(s) + Ni(NO3)2(aq) → Fe(NO3)2(aq) + Ni(s) E. all of the above
Monday, July 30, 2012 at 11:02pm

Chemistry
How much ethanol C2H50H in liters d=0.789g/ml must be dissolved in water to produce 190.5 of 1.65M c2H50H ? Molarity problem. Who helps me to solve it for me. My calculation 0.789g/ml x 1000ml/46.06 = 17.12M 17.12M = 190.5 x 1.65 17.12M = 314.325 x= 314.325/17.12 x = 18.36ML I...
Monday, July 30, 2012 at 10:34pm

Inorganic Chemistry
1) 5.0 mL of 6.0 x 10^-4 potassium 5.0 mL of the solution prepared above are then mixed with
Monday, July 30, 2012 at 10:28pm

Chemistry
. In a biochemical reaction, A + B-->C with äG = 30 kJ/mol. Which of the following reactions might be effectively coupled to this reaction so that it becomes more spontaneous? I. C + D are the reactants, and B + E are the products äG = -40 kJ/mol II. C + D are the...
Monday, July 30, 2012 at 4:11pm

Chemistry
A nine liter tank has 150 atmospheres of bromine in it at 27°C. What is the added mass of the tank due to the gas?
Monday, July 30, 2012 at 2:46pm

Chemistry
What is the overall standard free-energy change for the following two reactions? A + B-->2C äG = äG1 C + D-->E äG = äG2 a)äG1 + äG2 b)äG1 + 2äG2 c)äG2 – äG1 d)2äG2 – äG1 e)äG1äG22
Monday, July 30, 2012 at 2:00pm

Chemistry
If at a certain instant during the course of the reaction 2 NO2(g) + F2(g) ¨ 2 NO2F(g), the rate of formation of the product were 0.16 mol/L∙s, how fast would the F2 be disappearing (also in mol/L∙s) at that same instant in time? A) 0.16 mol/L∙s B) ...
Monday, July 30, 2012 at 1:58pm

Chemistry
If the rate of formation of ammonia is 0.345 M/s, what is the rate of disappearance of N2? 1/2N2(g)+3/2H2(g)-->NH3(g) a. 0.173 M/s b. 0.345 M/s c. 0.690 M/s d. 245 M/s e. 0.518 M/s
Monday, July 30, 2012 at 1:58pm

Chemistry
Given the following data, determine the rate constant of the reaction 2NO(g) + Cl2(g) 2NOCl(g) Experiment [NO] (M) [Cl2] (M) Rate (M/s) 1 0.0300 0.0100 3.4 x 10–4 2 0.0150 0.0100 8.5 x 10–5 3 0.0150 0.0400 3.4 x 10–4 a. 1.13 M –2s–1 b. 9.44 M –2s...
Monday, July 30, 2012 at 1:57pm

Chemistry
Heat transfer from the system to the surroundings has a large effect on äSsurr ___________. a. when the temperature of the surroundings is low. b. when the temperature of the surroundings is high. c. when the temperature of the system is low. d. when the temperature of ...
Monday, July 30, 2012 at 1:51pm

Chemistry
What is the entropy change to the surroundings when 1 mol of ice melts in someone’s hand if the hand temperature is 32°C? Assume a final temperature for the water of 0°C. The heat of fusion of ice is 6.01 kJ/mol. a. –188 J/K d. b. –22.0 J/K c. –19.7...
Monday, July 30, 2012 at 1:51pm

Chemistry
If 1 mol of ice melts at its melting point of 273 K, the entropy change for the ice is 22.0 J/K. If the ice melts in someone’s hand at 34°C, what is the change in the entropy of the universe? Assume a final temperature for the water of 0°C. The enthalpy of fusion ...
Monday, July 30, 2012 at 1:50pm

Chemistry
Indicate which of the following has the highest entropy at 298 K. 0.5 g of HCN 1 mol of HCN 2 kg of HCN 2 mol of HCN All of the above have the same entropy at 298 K.
Monday, July 30, 2012 at 1:49pm

Chemistry
The standard molar entropy of lead(II) bromide (PbBr2) is 161 J/mol • K. What is the entropy of 2.45 g of PbBr2? a. +1.07 J/K b. –1.07 J/K c. +161 J/K d. –161 J/K e. 0 J/K
Monday, July 30, 2012 at 1:47pm

Chemistry
Calculate DeltaS0 for the formation of 1 mol of HI(g) from its elements given the following information: S0[H2(g)] = 131 J/mol∙K S0[I2(s)] = 116 J/mol∙K S0[HI(g)] = 206 J/mol∙K. A) 82 J/K B) 165 J/K C) 247 J/K D) 329 J/K
Monday, July 30, 2012 at 1:46pm

Chemistry
For which reaction is delta Ssys > 0? A) CH4(g) + 2 O2(g) ¨ CO2(g) + 2 H2O(l) B) NH3(g) + HCl(g) ¨ NH4Cl(s) C) 2 NH4NO3(s) ¨ 2 N2(g) + O2(g) + 4 H2O(g) D) HCl(aq) + NaOH(aq) ¨ NaCl(aq) + H2O(l)
Monday, July 30, 2012 at 1:45pm

Chemistry
8. The usual partial pressure of oxygen that people get at sea level is 0.20 Atm., that is, a fifth of the usual sea level air pressure. People used to 1 Atm. air pressure begin to become "light-headed" at about 0.10 Atm oxygen. As a rule of thumb, the air pressure ...
Monday, July 30, 2012 at 1:21pm

chemistry
what is the volume of a sphere that has a radius, r = 3 in.
Monday, July 30, 2012 at 11:36am

Chemistry
If you add 16g of sacicylic acid to 84g of an ointment base, what is the final concentration (w/w) the product? _______
Monday, July 30, 2012 at 10:11am

chemistry
If 35.7{\rm mL} of 0.205{\rm M} {\rm KOH} is required to completely neutralize 20.0{\rm mL} of a {\rm HC_2H_3O_2} solution, what is the molarity of the acetic acid solution? {\rm HC_2H_3O_2}(aq) + {\rm KOH}(aq) \to {\rm KC_2H_3O_2}(aq) + {\rm H}_{2}{\rm O}(l)
Monday, July 30, 2012 at 5:36am

chemistry
If you add 8g of benzoic acid to 92g of an ointment base, what is final concentration (w/w) the product? _______________
Sunday, July 29, 2012 at 11:37pm

chemistry
How much concentrated hydrochloric acid solution 36% HCL by mass d=1.18g/ml in milliliters is required to produce 11.0L of 0.296 M HCL? My calculation 1.18 x 1000ml x 0.36/36.5 = 11.6M 11.6M = 11000ml x 0.296 11.6m = 3256ml x= 3256ml/11.6 x= 280ml. I am not sure the right ...
Sunday, July 29, 2012 at 9:36pm

chemistry
the following reaction consumes 2.6kg of CO(g): CO(g) + H2O(g) --> CO2(g) + H2(g) how many total liters of gas are formed if the products are collected at STP?
Sunday, July 29, 2012 at 8:33pm

Chemistry
A 1.50- gas sample at 735 and 25.0 contains 5.00 radon-220 by volume. Radon-220 is an alpha-emitter with a half-life of 55.6 . How many alpha particles are emitted by the gas sample in 4.00 minutes?
Sunday, July 29, 2012 at 8:03pm

Chemistry
how does a formula of Iron(III) and ethylenediamine, assuming a coordination number of 6 look and what is it's name and written transition metal formula
Sunday, July 29, 2012 at 2:58pm

Chemistry
how does a fomula of Iron(III) and ethylenediamine, assuming a coordination number of 6 look and what is it's name?
Sunday, July 29, 2012 at 1:33pm

chemistry
Calculate the PH concentrated hydrochloric acid if this solution is 24.8% HCL by weight and has a density of 1.16g/ml. I do not understand the right answer 0.90PH Why? Please help My calculation 1.18g/ml x 1000ml x 0.248/36.5 = 7.8M I cannot do?
Sunday, July 29, 2012 at 1:09pm

Chemistry
Concentrated hydrochloric acid is a 38% solution of HCL in water and has a density of 1.18g/ml. How many milliliters of concentrated hydrochloric acid are needed to prepare 500ml of 1:200 HCL solution? The answer is not 2.12ml My calculation: 1.18g/ml x 1000ml x 0.38/36.5 = 12...
Sunday, July 29, 2012 at 1:00pm

Chemistry
Ammonia is a stronger ligand than is the chloride ion. What does this statement mean?
Sunday, July 29, 2012 at 11:26am

chemistry
difference between 2hcl and hcl
Sunday, July 29, 2012 at 4:44am

chemistry
An aqueous solution is made using 137g of diluted to a total solution volume of 1.30L .Calculate the molarity.molality and mass percent of solution.*assume a density of 1.08g/ml for the solution..
Saturday, July 28, 2012 at 2:44pm

chemistry
Glutamate (Glu–) is the conjugate base form of glutamic acid (HGlu). The Ka of glutamic acid is 5.012 x 10^–5. You titrate 50 mL of 0.10 M sodium glutamate solution with 0.05 M HCl solution. Calculate the pH of the solution at the equivalence point. Ive been trying ...
Saturday, July 28, 2012 at 11:34am

chemistry
The Ksp for calcium fluoride (CaF2) is 3.9 x 10^–11 at 25°C. How many moles of solid NaF must be added to 1.00 L of 0.100 M CaCl2 in order to precipitate CaF2? Please help me set up this ICE table and understand how to solve this!! thank you!!
Saturday, July 28, 2012 at 11:33am

chemistry
How much ethanol is required to make a 2L of a 70%ww solution?
Saturday, July 28, 2012 at 4:49am

Chemistry
Use Ksp to find the concentration of an ion in a saturated solution. Consider a 2.50E-3 M solution of Al2(SO4)3. (a) What [OH^-] is required to initiate precipitation of Al^3+ from the solution? (b) What [OH^-] is required to lower the [Al^3+] to 2.00E-7 M ?
Saturday, July 28, 2012 at 12:04am

Chemistry
Calculate the solubility of ZnCO3 in .050 M Zn(NO3)2. Ksp= 3.0*10^-8 solubility= 1.7*10^-4
Friday, July 27, 2012 at 7:35pm

Chemistry
What volume (in liters) is occupied by 3.85×10^22 nitrogen molecules at 105 C and 255 mmHg?
Friday, July 27, 2012 at 5:24pm

chemistry
Determine the activity of 1.11 g of 88Ra226 (a) in disintegrations per second (Bq) (b) and in Curies (Ci). The half-life is 1600 yr (1 yr = 3.156 x 10^7 s). 1 Ci is equal to 3.7 x 10^10 Bq.
Friday, July 27, 2012 at 5:19pm

AP Chemistry
If you were to draw diagrams (such as that shown on the right) representing aqueous solutions of each of the following ionic compounds, how many anions would you show if the diagram contained six cations? (a) NiSO4, (b) Ca(NO3)2, (c) Na3PO4, (d) Al2(SO4)3
Friday, July 27, 2012 at 11:13am

chemistry .....please help
Which of these temperatures is closest to 100 K? A. -173 °C B. 18 °C C. 0 °F D. 212 °F
Thursday, July 26, 2012 at 9:07pm

chemistry .....please help
When a bond is formed, energy is _________ the environment. A. released into B. released from C. kept stable in
Thursday, July 26, 2012 at 7:03pm

Chemistry
Find the volume, in L, of 100g gas mixture containing 10.0 mol% hydrogen in nitrogen at 30.0C and 5.00 atm. Use the avg molecular wt. what is the molar concentration of hydrogen, in mol/L, in the gas mixture? what is the average mass denisity in g/L
Thursday, July 26, 2012 at 4:19pm

chemistry
You are given 50 mL of .25 M citric acid. How many moles of NaOH would you need to add to obtain a soln with a pH of 6.7? Assume volume unchanged Ka1=7.4E-4 Ka2=1.7E-5 Ka3=4E-7
Thursday, July 26, 2012 at 12:58pm

chemistry
You have .1 moles of H3PO4 in a soln with a total volume of 250 mL. You then add .15 moles of NaOH and dilute the soln to a total volume of 1L calculate the pH of the resulting soln and the concentrations of all aqueous species. Thanks!!!!
Thursday, July 26, 2012 at 12:50pm

chemistry
How many moles of compound are in 26.5g of Na2CO3 x 10H2O?
Thursday, July 26, 2012 at 12:33pm

chemistry
What does 1.5 fold dilution and 2.5 fold dilution mean?
Thursday, July 26, 2012 at 11:28am

chemistry
a mixture of NaCl and NaBr has a mass of 2.06 g and is found to contain 0.75 g of na what is the mass of NaBr in the mixture ?
Thursday, July 26, 2012 at 9:31am

chemistry
Suppose you mix 50 grams of CO and 10 grams of H2. How many grams of methanol can be produced?
Thursday, July 26, 2012 at 7:57am

chemistry
A sample of gas with a mass of 1.62 g occupies a volume of 941 mL at a pressure of 748 torr and a temperature of 20.0 C. What is the molar mass of the gas?
Thursday, July 26, 2012 at 7:56am

chemistry
What does 1.5 fold dilution and 2.5 fold dilution mean?
Thursday, July 26, 2012 at 2:47am

chemistry .....please help
The direction that heat will flow is BEST determined by _____. A. energy B. pressure C. temperature D. potential energy
Thursday, July 26, 2012 at 12:31am

chemistry .....please help
A 54 kg high jumper has a gravitational potential energy of 1,067 J at the height of his jump. How high did he jump? A. 1.2 m B. 2.0 m C. 3.2 m D. 4.1 m
Wednesday, July 25, 2012 at 11:30pm

chemistry .....please help :)
Sitting in a chairlift, Rebecca has a gravitational potential energy of 5,997.6 J. If Rebecca has a mass of 51 kg, how high off the ground is the lift? A. 6 m B. 12 m C. 118 m D. 612 m
Wednesday, July 25, 2012 at 9:16pm

chemistry
I need to wtite a balanced equation and indicate the type of reaction for these questions 1) ammonium nitrite= nitrogen+ water 2) ammonia+ oxygen = nitrogen (ii) oxide + water 3) barium chloirde + sodium sulfate= sodium chloride + barium sulfate 4) iron(iii) oxide + carbon ...
Wednesday, July 25, 2012 at 7:03pm

chemistry
I need to write a balanced equation and indicate the type of reaction phosphoric acid + magnesium hydroxide= magnesium phosphate+ water
Wednesday, July 25, 2012 at 6:57pm

chemistry
What is the electronic transition for LiCl using this equation 1/(7.01 ×〖10〗^(-7) )= R_H (1/4- 1/(n_f^2 ))
Wednesday, July 25, 2012 at 6:35pm

chemistry
When the conductivity is at a minimum, what must be true about the amount of Ba(OH)2 compared to H2SO4? The Ba(OH)2 dissociates as Ba+2 + 2 OH-. H2SO4 dissociates as 2 H+ + SO4-2. Why does it not conduct at this low point? Why does it conduct more before and after this minimum...
Wednesday, July 25, 2012 at 3:55pm

chemistry
When do phase transitions occur in molecules?
Wednesday, July 25, 2012 at 10:18am

chemistry
if the solute is MgSO4 and it is disolved in 800g water water are the ideal melting and boiling pionts of the solution?
Wednesday, July 25, 2012 at 9:00am

chemistry
A 20.0 mL sample of 0.687 M HBr is titrated with a 0.216 M NaOH solution. The pH after the addition of 10.0 mL of NaOH is __________. A. 0.413 B. 0.386 C. 0.163 D. 0.579 E. 0.237
Tuesday, July 24, 2012 at 10:44pm

chemistry
A 20.0 mL sample of 0.687 M HBr is titrated with a 0.216 M NaOH solution. The pH after the addition of 10.0 mL of NaOH is __________.
Tuesday, July 24, 2012 at 10:40pm

chemistry
A steel container with a volume that cannot change is filled with 123.0atms of compressed air at 20.0°C. It sits out in the sun all day, and its temperature rises to 55.0°C. What is the new pressure?
Tuesday, July 24, 2012 at 7:14pm

chemistry
A steel container is filled with 5.00atm of nitrogen, 2.00atm of oxygen, and 0.50atm of argon. What is the total pressure in the vessel and the mole fraction of each gas?
Tuesday, July 24, 2012 at 7:14pm

chemistry
7H2O2(aq) + N2H4(g) ¨ 2HNO3(g) + 8H2O(g) If the rocket engine contains 1500.0 grams of H2O2 and an excess of N2H4, what volume of water vapor will be produced when the rocket fires up to a temperature of 540‹C and a pressure of 1.2atm?
Tuesday, July 24, 2012 at 7:13pm

chemistry
Silver tarnishes (turns to Ag2S) in the presence of oxygen and hydrogen sulfide according to the following equation: 4Ag(s) + 2H2S(g) + O2(g) ¨ 2Ag2S(s) + 2H2O(l) Usually, H2S is the limiting reactant. If a silver spoon is placed in a container that holds 56.7mL of ...
Tuesday, July 24, 2012 at 7:13pm

chemistry
If the rocket engine contains 1500.0 grams of H2O2 and an excess of N2H4, what volume of water vapor will be produced when the rocket fires up to a temperature of 540°C and a pressure of 1.2atm?
Tuesday, July 24, 2012 at 7:11pm

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