Monday

May 25, 2015

May 25, 2015

Number of results: 53,908

**chem**

calculate the molality of a solution of 2.34g acetic acid, HC2H3O2, in 35.0 g water
*October 11, 2011 by michael*

**Chemistry**

Calculate the solubility of AgCl in the following solution: 100mL of .004 M CaCl2
*November 7, 2011 by Kevin*

**AP Chemistry**

The solubility of solid Ce(IO3)3 in a 0.20 M KIO3 solution is 4.4 10-8 mol/L. Calculate Ksp.
*December 4, 2011 by Bill *

**chemistry**

Calculate the number of moles of each ion in 10.5 mL of 0.205 M cadmium phosphate solution.
*January 22, 2012 by student*

**chemistry**

Calculate the number of moles of each ion in 10.5 mL of 0.205 M cadmium phosphate solution.
*January 22, 2012 by diana*

**chemistry**

Calculate the grams of K2CO3 required to prepare 546.0 mL of a 0.789 g/L K+ solution.
*February 15, 2012 by donald*

**Chemistry**

Calculate the molality of a solution prepared by dissolving 31.6 g of Fe2O3 in 750. g of water
*April 8, 2012 by Tina*

**Chemistry**

Calculate the grams of solute required to make 2500mL of 90% saline solution?
*May 17, 2012 by Morgan*

**gen chemistry**

calculate the percent m/v concentration of a 5L solution containing 500g NaCl
*May 18, 2012 by ashia3*

**College Biology**

Calculate the concentration in Moles for a 5mgMgCl2 sample in 2L of solution. Then how many ions are in it?
*September 9, 2012 by cutiepie*

**Chemistry**

How would I calculate the mass of 20ml of a 3% hydrogen peroxide from a 30% H2O2 solution?
*September 26, 2012 by John *

**Chemistry**

Calculate the pH and the pOH of an aqueous solution that is 0.025 M in HCl(aq) and 0.075 M in HBr(aq) at 25°C.
*October 6, 2012 by Alex*

**chemistry**

calculate the mass of sodium hydroxide needed to prepare 100 ml of a .10 m solution
*October 7, 2012 by mike*

**chemistry**

calculate the mass of sodium hydroxide needed to prepare 100 ml of a .10 m solution
*October 7, 2012 by mike*

**chemistry**

Calculate the grams of solute needed to prepare each of the following. 55.0 ml of a 6.50 hcl solution.
*November 2, 2012 by mary*

**Chem help **

Calculate the pH of a solution containing 0.00001 moles of H3O per liter.
*November 16, 2012 by Lindsey*

**Chemistry**

Calculate the mass concentration of H2SO4 in a solution of 36%, with density 1.84g/cm3
*January 20, 2013 by Anonymous*

**general chemistry**

Calculate the molarity of each of the following solutions.70.8g C2H60 in 2.51L of solution
*March 7, 2013 by kelia*

**Chemistry**

7. A solution is prepared by dissolving 8.5 g NaHCO3 and 12.7 g Na2CO3 in 500.0 mL of water. Calculate the pH.
*March 20, 2013 by Nick*

**Chemistry**

7. A solution is prepared by dissolving 8.5 g NaHCO3 and 12.7 g Na2CO3 in 500.0 mL of water. Calculate the pH.
*March 20, 2013 by Nick*

**Chemistry**

Calculate volume of 6MHCL required to prepare a 250 ml of a 0.15MHCL solution??
*April 9, 2013 by Karen*

**Chemistry**

Calculate volume of 6MHCL required to prepare a 250 ml of a 0.15MHCL solution??
*April 9, 2013 by Karen*

**chem**

calculate the concentration of all ions present in 58.7 mg NH4Br in 500 mL of solution
*April 11, 2013 by celine*

**Chemistry II**

Calculate the pH at the equivalence point in the titration of 50ml of 0.20 M methylamine (Kb=4.3*10^-4) with a 0.40 M HCL solution.
*May 3, 2013 by Katie*

**Chemistry**

If 50 mL of a saturated solution of KClO3 at 55¡ÆC is cooled to 15¡ÆC, calculate the mass of precipitate that will form
*May 20, 2013 by LOL*

**gpc**

Calculate the molarity of a bleach solution that is 8% by mass (m/v) or 8g/100mL sodium hypochlorite.
*March 3, 2014 by samry *

**Chemistry **

Calculate the pH of the solution that results from mixing 30.0 mL of 0.050 M HCN(aq) with 70.0 mL of 0.030 M NaCN.
*March 19, 2014 by Anonymous*

**chemistry**

Calculate the molality of sulphuric acid solution in which mole fraction of water is .85
*June 3, 2014 by swastika*

**chemistry**

calculate the moles of solute present in 1.25 centimeter cube of 0.5 M h3po4 solution
*June 19, 2014 by hifsa*

**CHEM**

calculate the molality of a solution formed by dissolving 27.8g of LiI in 500mL of water
*October 12, 2014 by Anonymous*

**chemistry**

Calculate the pH of 0,3g calcium hydroxide dissolved in water to give 500ml solution.
*October 26, 2014 by lala*

**organic biochemistry **

Calculate the number of moles of ZnCl2, in 100. mL of 0.600M solution.
*November 5, 2014 by hannah*

**Chemisty**

calculate the concentration of the solution of 6.4g calcium sulafte is added to 0.125l of water
*December 18, 2014 by EFonts*

**AP Chemistry**

A solution is prepared by mixing 0.0200 mol CH2Cl2 and 0.0500 mol 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, ...
*March 22, 2010 by Sarah*

**chemistry**

A solution is prepared by mixing 0.0433 mol CH2Cl2 and 0.0623 mol 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, ...
*May 4, 2010 by bob*

**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*

**Chemistry**

What is the equilibrium partial pressure of water vapor above a mixture of 37.5 g H2O and 62.5 g HOCH2CH2OH at 55 degree C. The partial pressure of water at 55 degree C is 118.0 mm Hg. Assume ideal behavior for the solution.
*February 19, 2012 by Nurcan*

**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*

**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**

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**

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*

**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*

**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**

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*

**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*

**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*

**Pre-calculus ( Absolute value)**

Why does |7 + 3x| = x -1 have no solution? I could plug in, for example 5, and the answer would be positive. Thank you =)
*May 10, 2015 by Lucina*

**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*

**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*

**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**

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*

**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*

**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*

**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**

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*

**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*