Monday

April 27, 2015

April 27, 2015

Number of results: 53,495

**Chemistry**

A solution is prepared by mixing 0.0400 mol CH2Cl2 and 0.0700 mol of CH2Br2 at 25°C. Assuming the solution is ideal, calculate the composition of the vapor (in terms of mole fractions) at 25°C. At 25°C, the vapor pressures of pure CH2Cl2 and pure CH2Br2 are 133 and 11.4 torr, ...
*February 20, 2011 by Katrina*

**Setting up a chem problem**

Magnesium reacts with water in the equation, Mg+2H²O-->Mg(OH)²+H². You have 8.1 g of magnesium available. This means you will need ___ g of water to use all the magnesium. This seems sorta simple, but how can i set it up? These are stoichiometry problems. They can be solved...
*January 18, 2007 by Briana*

**Chemistry**

Given the information below, calculate the heat provided by combustion of 66.1g of propane (C3H8). ΔHf° (C3H8(g)) = -103.85 kJ ΔHf° (CO2(g)) = -393.5 kJ ΔHf° (H2O(ℓ)) = -285.8 kJ Can Someone explain this in detail? i have to answer this type of problems on...
*November 6, 2012 by bOB*

**chemistry**

The combustion of a compound CxHyOz yields CO2 + H2O; all of th carbon in the CO2 came from the compound, all of the hydrogen in the H2O came from the compound; and all of the oxygen in the H2O came from the compound. The oxygen in the CO2 came from the atmosphere.
*November 5, 2012 by Anonymous*

**Chemistry**

If 48.1 g of solid Al2S3 and 6.68 mL of liquid H2O are reacted stoichiometrically according to the balanced equation, how many grams of solid Al2S3 remain? Al2S3(s) + 6H2O(l) → 2Al(OH)3(s) + 3H2S(g) I found that the limiting reagent, .6406mol of Al2S3 and .1226mol of H2O...
*June 4, 2010 by Judy*

**chemistry**

1)The element nickel has ccp packing with a face-centered cubic unit cell. The density of nickel is 8900 kg/m3 and the cell volume is 4.376 x 10-23 cm3. Calculate the value of Avogadro's number to three significant figures based on these data. (Note: the value may differ from ...
*February 4, 2010 by blasting*

**science**

In the lab you need to make 1.00 L of a 0.300 M NaCl solution. You had previously made a 0.950 M NaCl solution that you can dilute to form your new solution. How many mL of the concentrated solution would you use to make the dilute solution?
*November 2, 2011 by liz*

**Chemistry **

A solution is prepared by dissolving 25.0 g of pure HC2H3O2 and 25.0 g of NaC2H3O2 in 700 mL of solution (the final volume). (a) What is the pH of the solution? (b) What would the pH of the solution be if 65.0 mL of 0.650 M NaOH were added? (c) What would the pH be if 40.0 mL ...
*February 21, 2015 by Dean*

**chemistry**

if the pH of a half-neutralized acid solution is 5.4, how would you find the [H+] of the the solution. There is 1.0 g of L-ascorbic acid which was dissolved in 100 ml of water. That solution was split in two and 50 ml of the solution was titrated with 0.2 M NaOH (13 ml NaOH). ...
*April 17, 2008 by tom*

**Chemistry HELP!**

In order to standardize a KMnO4 solution, 0.3498 g Na2C2O4 was dissolved in 30 mL water and 15 mL 3.0 M H2SO4. The KMnO4 solution was added to the Na2C2O4 solution until a pale pink color persisted. The titration took 29.5 mL of KMnO4 solution. What is the concentration of the...
*May 6, 2013 by Prue*

**Chemistry HELP!**

In order to standardize a KMnO4 solution, 0.3498 g Na2C2O4 was dissolved in 30 mL water and 15 mL 3.0 M H2SO4. The KMnO4 solution was added to the Na2C2O4 solution until a pale pink color persisted. The titration took 29.5 mL of KMnO4 solution. What is the concentration of ...
*May 6, 2013 by Prue*

**Math**

1. In the lab, Deon has two solutions that contain alcohol and is mixing them with each other. Solution A is 40% alcohol and Solution B is 12% alcohol. He uses 1000 milliliters of Solution A. How many milliliters of Solution B does he use, if the resulting mixture is a 32% ...
*May 2, 2014 by Amy*

**Calculating Chi Squared**

I did a biology experiment and I have to use the chi^2 method to calculate statistical significance. I got data at different time points and I just want to make sure what I'm calculating this right. The data I got for one time point are 6 and 23 I know the equation for chi^2 ...
*October 28, 2011 by Catherine*

**Chem**

You've just prepared a solution by transferring 20.0 g of glucose into a 1.0 - L volumetric flask, and adding water to the mark. Calculate the concentration of the glucose solution in terms of millimoles/Liter, mg/mL, and % (m/v). Ok, I think i'm overwhelmed by the wordinng of...
*September 7, 2009 by Britt*

**urgent i need help within an hour!**

Ascorbic acid (vitamin C, C6H8O6) is a water-soluble vitamin. A solution containing 83.3 g of ascorbic acid dissolved in 210. g of water has a density of 1.23 g/mL at 55°C Calculate the molarity of ascorbic acid in this solution. i got 2.77 but its wrong
*January 21, 2013 by Samantha*

**AP chemistry**

A solution of sodium hydroxide is standard- ized against potassium hydrogen phthalate (KHP, formula weight 204.2 g/mol). From the following data, calculate the molarity of the NaOH solution: mass of KHP 1.894 g; buret reading before titration 0.13 mL; buret reading after ...
*October 24, 2010 by Anonymous*

**Chemistry**

A solution of sodium hydroxide is standard- ized against potassium hydrogen phthalate (KHP, formula weight 204.2 g/mol). From the following data, calculate the molarity of the NaOH solution: mass of KHP 1.654 g; buret reading before titration 0.23 mL; buret reading after ...
*October 4, 2011 by Broy*

**chemistry**

A solution of sodium hydroxide is standard- ized against potassium hydrogen phthalate (KHP, formula weight 204.2 g/mol). From the following data, calculate the molarity of the NaOH solution: mass of KHP 1.744 g; buret reading before titration 0.13 mL; buret reading after ...
*September 19, 2012 by cheri*

**Analytical chemistry**

A 24.393 g sample of aqueous waste leaving a fertilizer manufacturer contains ammonia. The sample is diluted with 80.601 g of water. A 12.404 g aliquot of this solution is then titrated with 0.1059 M HCl. It required 31.61 mL of the HCl solution to reach the methyl red ...
*April 4, 2013 by Ashley*

**math**

given that R= 2p(squared) divided by Q-3 1)Calculate the value of R when P=6 and Q=12. 2)rearrange the formula to make Q the subject.
*April 7, 2008 by scott*

**Algebra 2/trig**

How would I calculate the following function value? tan = 29degrees 36feet
*May 15, 2010 by Brenna*

**Calculus**

Use Newton's Method with the function f(x)=x^2-2 and initial value Xo=2 to calculate x1,x2,x3. I have no idea how to do this
*October 27, 2010 by Don*

**Math**

Given that f(x) = a log x for some constant a, and that f(7) 5:282, determine the value of a and calculate f(13) to 3 decimals.
*February 10, 2011 by Diane*

**math**

How do I calculate the present value on a deferred annuity for $75,000 for 3 years at an interest rate of 7%.
*March 25, 2012 by cathyj*

**Chemistry**

Calculate the solubility of cadmium sulfide, CdS, in mol/L, given the Ksp value as 8.0 x 10^-27.
*April 9, 2012 by Anonymous*

**trig**

Given that cos A = 5/13 and A and B are both acute angles, calculate the value of Sin2A and Cos2A
*June 6, 2014 by uche*

**maths litle**

calculate the value of 14000after2years if it is invested at 12%per year simple interest
*October 22, 2014 by nkanyiso*

**math**

Calculate the mean value for the number of heads appearing in a simultaneous throw of 3 coins.
*March 21, 2015 by gourav *

**Chemistry**

A solution of NaOH(aq) contains 7.7 grams of NaOH in 93 mL of solution. Calculate the pH at 25◦C. ---- 7.7 grams x (1 mol/39.997 grams) = 0.19 mol 0.19 mol/0.093 L = 2.07 M pOH = -log(2.07) = -0.316 ---- Am I doing anything wrong? Why am I getting a negative pOH/pH ...
*February 11, 2015 by Edwin*

**Chem**

There are three questions in particular that I am having problems with. Here they are 1. A standard solution of FeSCN2+ is prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN. The equilibrium concentration of FeSCN2+ ([FeSCN2+]std) for this standard ...
*January 19, 2009 by Mark*

**math**

A group of people planned to contribute equally towards a water project which needed Ksh 200,000 to complete, however, 40 members of the group without from the project. As a result, each of the remaining members was to contribute Kshs 2,500. (a) Find the origina number of ...
*February 21, 2015 by kudu*

**chemistry**

220 ml of an HCl solution that is 31.4% by mass is required to neutralize .50 gal of the chlorine solution. what is the molarity of the OH- of the clorine solution? chlorine solution is NaOCl in NaOH
*April 19, 2011 by Bob*

**college algebra**

a chemist needs to prepare 28 ounces of a 8% hydrochloric acid solution. find the amount of 14% solution and the amount of 7% solution he should mix to get this solution.
*April 20, 2015 by anna*

**Buffer Solution**

You have 500.0 mL of a buffer solution containing 0.30 M acetic acid (CH3COOH) and 0.20 M sodium acetate (CH3COONa). What will the pH of this solution be after the addition of 93 mL of 1.00 M NaOH solution?
*April 13, 2011 by Nicole*

**Science**

You have a stock solution of 3.5M glucose. You need a working solution of 0.5M glucose in a volume of 400ml. Explain how you make the solution. Also what is the concentration of the dilution solution?
*October 15, 2012 by Helper*

**Chemistry**

A mixture of ethane and ethene occupied 35.5 L at 1.000 bar and 405 K. This mixture reacted completely with 110.3 g of O2 to produce CO2 and H2O. What was the composition of the original mixture? Assume ideal gas behavior Im pretty sure i use dalton's law of partial pressures ...
*September 19, 2012 by Drew*

**chemistry (drbob222)**

I posted yesterday. Re: Chemistry (Sunday, October 4, 2009 at 12:49pm). Here's the information I left out. Number 3 simply states: nickel forms a large number of ammonia salts Ni^2+(NH3)m(Br)n . p(H2O) where m, n, and p represent the coefficients in the formula How do you know...
*October 4, 2009 by Anonymous*

**Chemistry**

In lab we did thermochemistry, where we are supposed to find the heats of solution, heat change of calorimeter and molar heat solution of the salt. I calculated that the calorimeter constant for the water we had was 883.194 Joules. We took 1/10 of a mole of NH4Cl and tried to ...
*October 31, 2010 by Rani*

**skyiline college**

A compound of carbon, hydrogen, and oxygen was burned in oxygen, and 2.00g of the compound produced 2.868 g CO2 and 1.567 g H2O. In another experiment, 0.1107 g of the compound was dissolved in 25.0 g of water. This solution had a freezing point of -0.0894 degrees C. what is ...
*December 8, 2012 by sevag*

**cal**

Use Euler's method with step size0.4 to estimatey(2) , where y(x) is the solution of the initial-value problem y'=4x+y^2, y(0)=1. . y(2)=
*March 12, 2012 by carlton*

**calculus 2**

Use euler's method with step size 0.2 to estimate y(1), where y(x) is the solution of the initial-value problem y'= -3x+y^2, y(0)=1
*March 13, 2012 by Geminese*

**calculus 2**

Use euler's method with step size 0.2 to estimate y(1), where y(x) is the solution of the initial-value problem y'= -3x+y^2, y(0)=1
*March 13, 2012 by Geminese*

**calculus**

Use Euler's method with step size 0.2 to estimate y(1), where y(x) is the solution of the initial-value problem. y' = 5x + y^2, y(0)=-1.
*March 14, 2012 by Carlton*

**CAL 2**

Use Euler's method with step size 0.2 to estimate y(1), where y(x) is the solution of the initial-value problem y'=5x+y^2, y(0)=-1 y(1)=
*March 15, 2012 by Josh*

**Cal**

Use Euler's method with step size 0.2 to estimate y(1), where y(x) is the solution of the initial-value problem. y' = 5x + y^2, y(0)=-1. y(1)=
*March 15, 2012 by McClain*

**chemistry**

x gm og Ag was dissolved in HNO3 and the solution was treated with excess of NaCl when 2.87 g of AgCl was precipitated. find the value of x?
*May 17, 2012 by aayushi*

**math**

Which is the value is in the solution set for the inequality -8-7x>6 A=-1 b=-2 c=-3 d=2 -8-7x>6 add 8 to each side -7x>14 -7/-7>14/-7 x<-2 since it is less then -2 should the answer be c=-3 Thanks
*January 3, 2013 by b6*

**Chemistry **

What is the [H+] of the 0.25 M HCl solution? I'm not given a Ka value, so I'm assuming I won't need one to solve this particular problem?
*April 7, 2013 by Marcus *

**Algebra 2**

solve each inequality or equation. Graph the solution. 5(absolute value 3w+2)-3>7 *Please show me the work
*October 15, 2014 by Alicia*

**chemistry**

Calculate the standared enthalpy of formation of solid Mg(OH)2 given the following data: 2Mg(s) + O29(g) →2MgO(s) ∆H = -1203.6kJ Mg(OH)2(s) →MgO(s) + H2O(l) ∆H= +37.1kJ 2H2(g) +O2(g) →2H2O(l) ∆H = -571.7kJ
*March 13, 2011 by melinda*

**Math, statistics**

Problem 1: The PDF of exp(X) (6/6 points) Let X be a random variable with PDF fX. Find the PDF of the random variable Y=eX for each of the following cases: For general fX, when y>0, fY(y)= Solution: f_x(ln(y))/y When fX(x) = {1/3,0,if −2<x≤1,otherwise, we ...
*March 31, 2015 by R*

**CHEM-vaporization**

A 50.0g piece of iron an 152°C is dropped into 20.0g H2O(l) at 89°C in an open, thermally insulated container. How much water would you expect to vaporize, assuming no water splashes out? The specific heats of iron and water are 0.45 and 4.21 respectively, and ÄHvap= 40.7 kJ ...
*February 6, 2009 by -*

**chemistry**

X is a solution,of dibasic of H2X. G is a solution containing 1.00g of NaOH in 250cm3 of solution . 24.60cm3 of solution F required 25.00cm3 of solution G . From your result and information provided above. (I)concentration of G in mol/dm3 (ii) concentration of F in mol/dm3 (...
*May 25, 2014 by john kelechi*

**Math**

A pharmacist is to prepare a 50 fluid ounce solution that contains 54% glucose. The pharmacy has a 30% solution and a 90% solution on hand. How many ounces of each solution should be mixed to prepare the desired perscription?
*February 26, 2010 by Madison*

**chemistry**

the density of a certain aqueous solution is 1.17g/ml, and the solution is 3.57% by mass NaOH. how many mL of this solution would you need to use in order to prepare 100.0 mL of .150 M NaOH solution?
*September 6, 2010 by zahra*

**CHEMISTRY**

1. How would you take 1L of an existing solution with a concentration of 1M and use it to make a new solution of 0.1 M? Be specific. 2. Would it be possible to easily create a 2 M solution from 100 mL of 1 M solution? Explain why or why not?
*January 16, 2013 by Anonymous*

**Chemistry**

1. How would you take 1L of an existing solution with a concentration of 1M and use it to make a new solution of 0.1 M? Be specific. 2. Would it be possible to easily create a 2 M solution from 100 mL of 1 M solution? Explain why or why not?
*January 16, 2013 by Anonymous*

**chemistry**

1)If 746.4 g of a substance is dissolved in 1723 g of benzene solvent, the freezing point of the solution is -9.19 oC. Calculate the apparent molar mass (g/mol) of substance. 2) What mass ( g ) of the solvent water should be mixed with 0.008595 L of the solute ethylene glycol ...
*January 20, 2010 by bubble*

**Chemistry**

Hi, I am trying to figure out how to calculate the average temperature of 2 different chemical solutions based upon the temperatures I measured. The question states: Find the average Ti of HCl & NaOH solutions. The Ti of NaOH solution is: 20.87 C The Ti of HCl solution is: 21....
*March 12, 2012 by Jules*

**Math**

A druggist mixes a 10% solution of iodine with a 15% solution of iodine. How much of each solution should be used in order to obtain 20 cubic centimeters of a 12% solution?
*February 10, 2010 by Vinnnie*

**Chem**

An aqueous KNO3 solution is made using 82.7 grams of KNO3, diluted to a total solution volume of 1.50 L. The density of this solution is 1.05 g/mL. What is the molality of this solution?
*May 2, 2011 by Ryan*

**Chemistry**

Calculate the number of grams of water produced from 30 g of oxygen gas. List only the number of grams of water. First, you will need to balance the equation above. Round to the nearest hundredth. And, as always, don't forget the units.C6H10+O2---->CO2+H2O
*August 5, 2010 by Jarred*

**chemistry**

1. A 123.00 liter sample of acetylene gas (C2H2) is reacted with excess oxygen at 27 C and 1 atm to produce carbon dioxide and water vapor. Calculate the following: a. The volume of CO2 produced at 1 atm and 400 C. b. The mass of H2O vapor produced.
*November 26, 2011 by britney*

**chemistry**

To extract gold from its ore, the ore is treated with sodium cyanide solution in the presence of oxygen and water. 4 Au(s) + 8 NaCN(aq) + O2(g) + 2 H2O(l) 4 NaAu(CN)2(aq) + 4 NaOH(aq) Determine the mass of gold that can be extracted if 27.4 g sodium cyanide is used.
*February 3, 2010 by r*

**chemistry**

To extract gold from its ore, the ore is treated with sodium cyanide solution in the presence of oxygen and water. 4 Au(s) + 8 NaCN(aq) + O2(g) + 2 H2O(l) 4 NaAu(CN)2(aq) + 4 NaOH(aq) Determine the mass of gold that can be extracted if 27.4 g sodium cyanide is used.
*February 3, 2010 by r*

**Chemisty**

Given the data in the table below, ∆Horxn for the reaction 3NO2(g) + H2O(l) → 2HNO3(aq) + 3NO(g) is __________ kJ. Substance ∆Horxn (kJ/mol) H2O(l)= -286 NO(g)= 90.0 NO2(g)= 34.0 HNO3(aq)= -207 NH3(g)= -46.0 A) -140 B) -508 C) -64 D) 140 E) 64
*September 17, 2013 by Jenny*

**Chemistry Dr. Bob**

This is in response to the fact that my experiment had me come up with my own.. I was supposed to measure out as close to 1g as possible of sodium bicarbonate as possible.. This is my lab procedures: Plastic Cup A 1. Measure out 50 mL of distilled water with a 100-mL graduated...
*March 3, 2015 by Jennie*

**Chemistry**

Sorry Dr. Bob, I wsa looking for the Sucrose, not all 16 calculations. Can you help me with the Sucrose? I have 93.954 mL of a generic cola solution. The solution contains: Molarity of H++1.005e-7 Molarity of OH- = 1.005e-7 Molarity of Sucrose(aq) = 6.386e-1 Molarity of Dye= ...
*November 3, 2011 by Emily*

**Chemistry**

Calculate the concentration of bromocresol green (BG) indicator It says that Molar absorptivity = Absorbance at a wavelength/ concentration of BG indicator I am having trouble calculating the concentration of BG. Other info: Stock solution of BG = 80.0 mg/L and molar mass = ...
*April 25, 2013 by Catherine*

**Chemistry- Le chatelier's Principle**

HOw would you predict the colour change or changes in number of states for the following: To a solution of 5 drops of 0.3 M K2CrO4 ans 2 drops of 0.3M NaOH add a drop at a time 0.1 M Ba(NO3)2 until a change is noticed. Given: BaCrO4(s) ---> Ba2+ + CrO42- 2CrO42-+2H+ --->...
*March 4, 2009 by meme*

**energy conversion**

A 5hp 230volt shunt motor takes 18 amp when operating at full load. The Shunt-field resistance is 115ohms and the armature resistance is 0.25 ohm. calculate the value of the starter resistor if the armature current is limited to 1.5 times the rated value at the starting ...
*September 20, 2010 by baskuuugin*

**chemistry**

You were given 25.00 ml of an acetic acid solution of unknown concentration. You find that it requires 29.60 ml of a 0.1050 M NaOH solution to exaclty neutralize this sample. A) What is the molarity of the acetic acid solution? B) what is the percentage of acetic acid in the ...
*October 20, 2011 by Rema*

**Chemistry**

Naoh (aq) + HCl (aq) --> NaCl (aq) + H2O (l) Using the dT determined in part 1, calculate the heat capacity of the calorimeter. Enthalpy of reaction= -58.3 kj/mol, Cs (NaCl = 3.91j/g C)density of 1 M NaCl = 1.037g/mL. dT= 12.88 degrees Celcius.50 mL of 2.00 M HCl and 50 ml ...
*November 12, 2012 by Annie*

**Chemistry**

The homework question is : Calculate the Delta H for the following reaction: C6H6 + O2 -> C + H2O(l) State whether the reaction is exothermic or endothermic. I'm not sure where to go with this but so far I balanced out the formula to this C6H6 + (3/2)O2 -> 6C2 + 3H2O I ...
*December 1, 2014 by Alexa*

**chemistry**

For Hg2+(aq) + 2e -> Hg(l) E=0.851 V This means that: A) Hg(l) is more readily oxidized than H_2(g); B) Hg^2+(aq) is more readily reduced than H^+(aq) C) Hg(l) will dissolve in 1 M HCl D) Hg(l) will displace Zn(s) from an aqueous solution of Zn^2+ ion ~~~~~~ Sooo...this ...
*March 31, 2009 by someone*

**Titration/Acid-base chem**

a .4000 M solution of nitric acid is used to titrate 50.00 mL of .237 M barium hydroxide (Assume that volumes are additive). a) Write a balanced net ionic equation for the reaction that takes place during titration. b) what are the species present at the equivalence point? c) ...
*May 6, 2007 by Keith*

**Chemistry**

A certain headache relief tablet is composed of monoprotic acetylsalicylic acid(C9H8O4(s)) and an inert filler. A 4.00 g tablet was crushed and dissolved to make 40.0 mL of solution. The solution was then titrated with 0.900 mol/L NaOH(aq). The volume of NaOH(aq) needed to ...
*June 9, 2011 by Maya*

**chem**

You have a large amount of 7.50M stock solution. You need 1.80L of 3.00M solution for an experiment. How would you prepare the desired solution without wasting any stock solution?
*November 8, 2012 by chemdummy*

**Chemistry**

A solution is prepared by dissolving 571.6 g of H 2SO4 in enough water to make 1000.0 mL of solution. The solution has a density of 1.3294 g/mL. (molar mass of H2SO4 = 98.08). What is the molar concentration of the solution?
*March 24, 2013 by Bill*

**Chemistry**

Consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of H2O(g). C2H4(g) + H2O(g) C2H5OH(g) Kc = 9.0 × 103 [C2H4]eq = 0.015 M [C2H5OH]eq = 1.69 M
*December 2, 2014 by Jane*

**Chemistry 2!**

consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of H2O(g) C2H4(g) + H2O(g) <--> C2H5OH(g) kc= 7.0* 10^3 [C2H4]= 0.010M [C2H5OH]= 1.99M
*December 10, 2014 by anonymous.*

**chemistry-Thermochemistry (grade 12)**

calculate enthalpy of H for the reaction N2H4(l) + 2H2O(l) -> N2(g) + 4H2)(l) Given the reactions N2H4(l) + O2(g) -> N2(g) + 2H2O(l) Enthalpy of H = -6.22.2 kJ H2(g) + (1/2)O2(g) -> H2O(l) enthalpy of H = -285.8 kJ/mol H2(g) + O2(g) -> H2O2(l) enthalpy of H = -187....
*February 16, 2012 by Rose Bud*

**chemistry-Thermochemistry (grade 12)**

calculate enthalpy of H for the reaction N2H4(l) + 2H2O(l) -> N2(g) + 4H2)(l) Given the reactions N2H4(l) + O2(g) -> N2(g) + 2H2O(l) Enthalpy of H = -6.22.2 kJ H2(g) + (1/2)O2(g) -> H2O(l) enthalpy of H = -285.8 kJ/mol H2(g) + O2(g) -> H2O2(l) enthalpy of H = -187....
*February 16, 2012 by Rose Bud*

**Chemistry **

When a 5.50g sample of solid sodium hydroxide dissolves in 100.0 g of water in a coffee cup calorimeter, the temperature of rises from 21.6 degrees C to 37.8 degrees C. Calculate Change of heat for the reaction in kJ (also in kJ/mol NaOH) for the solution process. Assume the ...
*October 10, 2011 by Jennifer *

**chemestry**

A calorimeter contains 16.0 of water at 15.0. When 1.60 of (a substance with a molar mass of 58.0 ) is added, it dissolves via the reaction and the temperature of the solution increases to 27.5. Calculate the enthalpy change, , for this reaction per mole of . Assume that the ...
*November 9, 2011 by Anonymous*

**Chemictry**

A calorimeter contains 32.0 of water at 11.5. When 1.70 of (a substance with a molar mass of 74.0 ) is added, it dissolves via the reaction and the temperature of the solution increases to 26.5. Calculate the enthalpy change, , for this reaction per mole of . Assume that the ...
*November 18, 2011 by Priscilla*

**chemistry**

A chemistry student weighs out 0.172 grams of acrylic acid (HCH2CHCO2) into a volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.1800 moles/liter NaOH solution. Calculate the volume of NaOH solution the student will need to add ...
*January 25, 2012 by Lucas*

**Chem**

Hydrogen peroxide decomposes according to the following: H2O2--> H2O(l) + 1/2O2(g); deltaH = -98.2kJ Calculate the change in enthalpy, deltaH, when 1.00g of Hydrogen peroxide decomposes
*November 19, 2009 by Lindsey*

**chemical formula**

Do i need a chemical formula to calculate the mols of FeSO4*7H20 when given the mols of Fe(II)? If so i only know that Fe(III) + H2SO4 + H3PO4 are the reactants, and FeSO4*H2O is the product. Help?
*May 22, 2011 by Meso*

**Chemistry (URGENT)**

Calculate the molarity of the Co^2+ ion in each of the solutions 1-5. The new molarity is given by the molarity of the stock solution multiplied by the dilution factor. Solution: Co(NO3)2 Original molarity: 0.160 Dilution #1: none D#2: 12mL to 16mL D#3: 8mL to 16mL D#4: 4mL to...
*December 15, 2010 by John*

**chemistry**

A 150.0-mL sample of Solution A is diluted to a total volume of 423 mL to form Solution B. If the concentration of Solution A was originally 20.0 mg/L, what is the concentration (in mg/L) of Solution B?
*September 18, 2011 by alex*

**Chemistry **

So my chem professor had a slide with a question that follows: If you combine 100 ml of 0.10 M HCl and 100 ml of 0.10 M NaOH, and find that the temperature goes up 0.67 degrees K What is ΔH° for the reac/on: OH(aq)- + H+(aq)->H2O(l)(c H2O= 4.18 J/°C sg, density of ...
*March 26, 2014 by Angely R. *

**Chemistry**

To illustrate the calculation, assume that 21.95 mL of a thiosulfate solution is required to reduce the iodine liberated by 20.85 mL of 0.0200M KIO3 and that 18.63 mL of the same thiosulfate solution reacts with the iodine replaced by 20.00 mL of an unknown solution of sodium ...
*April 26, 2013 by Marcus *

**P. Chemistry **

A solution of HNO2 is at equilibrium: HNO2(aq) + H2O(l) ⇔ H3O+(aq) + NO2-(aq) Water is added. After the water is added, is there any shift in the equilibrium?
*March 8, 2010 by Tommy*

**Maths**

A perfectly cylindrical container standing upright with a top and bottom(an oil drum or coke can for example) of area A has an empty mass of M and a height of H. It is filled with a liquid of uniform density(p)up to the height of h. When the container is full the centre of ...
*April 28, 2012 by Stephen*

**Finance**

The following balance sheet extract relates to the Allied Insurance Company Bonds Payable $1,000,000 Preferred Stock $2,000,000 Common Stock $3,000,000 Additional Information: 1. The bonds are 8%, annual coupon bonds, with 9 years to maturity and are currently selling for 90% ...
*April 4, 2015 by friend*

**chem 2**

indictae the reactant that is a bronsted lowry acid. HCN(aq) +H2O (l)---> H3O+(aq)=CN-(aq) HCN CN- H20 H30 i think it is HCN the weak acid substance which acts as a proton (H+) donor and CN the weak base? You are right. The HCN donates the proton (to H2O) so that makes HCN...
*April 30, 2007 by jane*

**Chemistry**

Ethylene glycol, HOCH2CH2OH, is used as antifreeze. It is produced from ethylene oxide, C2H4O, by the following reaction. C2H4O(g) + H2O(l) → HOCH2CH2OH(l) Use Hess's law to obtain the enthalpy change for this reaction from the following enthalpy changes. 2 C2H4O(g) + 5 ...
*December 13, 2009 by Mariam*

**chemistry **

Ethylene glycol, HOCH2CH2OH, is used as antifreeze. It is produced from ethylene oxide, C2H4O, by the following reaction. C2H4O(g) + H2O(l) → HOCH2CH2OH(l) Use Hess's law to obtain the enthalpy change for this reaction from the following enthalpy changes. 2 C2H4O(g) + 5 ...
*October 29, 2010 by caroline*

**Finding Delta G**

The following reactions are important ones in catalytic converters in automobiles. Calculate Delta G for each at 298 K. Predict the effect of increasing temperature on the magnitude of Delta G. 2CO(g) + 2NO(g) -> N2(g) + 2CO2(g) 5H2(g) + 2NO(g) -> 2NH3(g) + 2H2O(g) 2H2(g...
*March 29, 2013 by Amy*