Thursday

September 18, 2014

September 18, 2014

Number of results: 48,867

**Chemistry**

Consider the reaction, CH4(g) + 2 O2(g) => CO2(g) + 2 H2O(g). How many grams of H2O(g) will be made by the reaction of 17 moles of CH4(g) with 7 moles of O2(g)?
*November 29, 2010 by Alle*

**Chemistry**

Magnesium sulfate is often used it first aid hot-packs giving off heat when dissolved in water. When 2.00 g of MgSO4 dissolves in 15.0 mL of water (d= 1.00g/mL) at 25.0C, 1.51 kJ of heat is evolved. A) Write the balanced equation for this reaction. I have: MgSO4 + H2O --> ...
*January 28, 2007 by Chris*

**visual basic**

Im trying to get this program to average three number having a problem the sample nmubers im using are 6 6 2 average supposed to be 4.6667 but im just geting .6667 I think it has something to do with my s=value(i) not sure what i need to do now can anybody help? Dim no As ...
*October 8, 2009 by vsu1*

**AP chem**

A 0.345g sample of anhydrous BeC2O4, which contains an inert impurity, was dissolved in a sufficient water to produce 100ml of solution. A 20.0ml portion of the solution was titrated w/ KMnO4(aq). The balanced equation for the reaction that occurred is as follows: 16H^+(aq) + ...
*January 4, 2007 by michelle*

**Algebra!**

Can someone help me with these problems so i can do the rest of my textbook work on my own plz? What is the value of n so that the expression x^2+11x+n is a perfect square trinomial? (1 point) What is a solution of x^2+6x=-5? (1 point) What is the solution of x^2+14x+112=0? If...
*March 24, 2014 by Gabby*

**chemistry**

What is the freezing point of each solution? a)1.40mol Na2SO4 in 1750 g H2O Are these the right steps? 1.40mol Na2SO4 / 1.75kg = .8m 3 * 1.86 degrees C * .8m = 4.46 degrees C 4.46 degrees C - 1.86 degrees C = 2.6 degrees C
*April 29, 2010 by Jack*

**College Chemistry II**

What is the solubility of ZnCO3 at 25C in a buffer solution with a pH of 10.21? ZnCO3 <----> Zn++ + CO3 - CO3-- + H2O ----> HCO3- + OH- pOH = 14 10.21 = 3.79 [OH-] = 1.62x10^-4 M = [CO3--] = [Zn++] Ksp = [Zn++][CO3-] = (1.62x10^-4)( 1.62x10^-4) = 2.63x10^-8 when i...
*August 10, 2014 by Monica *

**Chemistry**

What is the molarity of a solution with 3.5mol of CaCl2 in 1.89L of solution What is the molarity of a solution with 16g of CH3OH in 487mL of solution
*March 4, 2009 by Ali*

**Chemistry**

A 2% solution of Hydrochloric acid is required for a procedure. A 5% solution is availabe. How much of the 5% solution will be required to make 1 L of solution?
*April 14, 2009 by Jessi*

**chemistry**

A solution contains 4.46 g KCl in 178 mL of solution. The density of the KCl solution is 1.11 g/ml. What is the percent (m/m) for the potassium chloride solution?
*October 9, 2010 by Samantha*

**Math**

If a mixture of a 6% acid solution with an 11% solution is to be made, how much of each solution is needed to make 10 liters of an 8% acid solution?
*September 2, 2012 by DAD*

**Chemistry**

The following three step mechanism has been proposed for the oxidation of iodide ion by peroxide: H2o2 + I^- ----> HOI + OH^- Slow OH^- + H^+ ----> H2O Fast HOI + H^+ + I^+ ---> I2 + H2O Fast A. What is the overall reaction described by this mechanism? B. What is the ...
*November 20, 2012 by Krissy *

**math**

50gm of a sample of ca(oh)s is dissolved in 50ml of 0.5N hcl solution. The excess of hcl was titrated with 0.3N -naoh. The volume of naoh used was 20cc. Calculate of naoh used was 20cc. Calculate % purity ca(oh)2 Who help me step by step
*December 22, 2013 by Fai*

**Chemistry(Please check answers)**

1) The standard molar entropy value of N2 (g) is 191.5 J/K-mol, of O2 (g) is 205.0 J/K-mol and of NO2 (g) is 240.0 J/K-mol. From these values we can calculate the Delta So for the reaction N2 (g) + 2 O2 (g)-> 2 NO2 (g) to be? I did products - reactants (240 X 2) - [191.5...
*April 23, 2012 by Hannah*

**AP Chem - to Dr. Bob**

I don't understand how to even start this problem: A mixture of H2(g), O2(g), and 2 mL of H2O is present in a 0.5 L rigid container at 25 degrees Celsius. The number of moles of H2 and the number of moles of O2 are equal. The total pressure is 1146 mmHg. Vapor pressure of ...
*January 23, 2007 by Belinda*

**math**

The table shows the closing value of a stock index for one week in March, 2004. a. Using the day as the x-value and the closing value as the y-value, write equations in slope-intercept form for the lines that represent each value change. b. What would indicate that the rate of...
*July 23, 2009 by ashlin*

**chem**

A solution contains 4.60 g KCl in 179 mL of solution. The density of the KCl solution is 1.11 g/mL What is the percent (m/m) for the potassium chloride solution? What is the molarity, M, for the potassium chloride solution? need help pls
*November 8, 2012 by byke*

**Linear Algebra**

I previously posted this question under the wrong topic. Which of the following choices is a solution for: (-3-i)x1 + (1-2i)x2 = 0 (-7-9i)x1 + (7-4i)x2 = 0 for any value of the variable t [x1] = ? [x2] A: [5] [1+7i] * t B: [5] [1-7i] * t C: [5] [-1-7i] * t D: [5] [-1+7i] * t
*December 4, 2009 by Michael*

**calculus**

solve the logarithmic equation. Be sure to reject any value of x that is not in the domain. In square root x+7=1 x= ? What is the decimal approximation to the solution? x= ?
*January 1, 2013 by NayNay*

**Math**

Let p and q be the roots of the polynomial mx^2 + x(2 - m) + 3. Let m1 and m2 be two values of m satisfying p/q + q/p = 2/3. Determine numerical value of m1/(m2)^2 + m2/(m1)^2. Please work the complete solution.
*April 23, 2013 by Watson*

**Math**

Let p and q be the roots of the polynomial mx^2 + x(2 - m) + 3. Let m1 and m2 be two values of m satisfying p/q + q/p = 2/3. Determine numerical value of m1/ (m2)^2 + m2/(m1)^2. Please work the complete solution.
*April 23, 2013 by Watson*

**Algebra 1**

23.what is the slope of a line parallel to a line represented by the equation x=2y-3? 19.what is the solution to the following system of equation? Y=4x-8 Y=2x 16.which graph below shows the function f(x)=-3x-1? 12.what is the solution to the following system of equations? Y=2x...
*January 21, 2012 by Elyon*

**chemistry**

1. calculate the volume of concentrated HNO_3 (68%)that is needed to prepare stock solution 0.25M in 1000mL volumetric flask. (density HNO_3 = 1.513 g/cm^3) 2. from above stock solution, determine volume needed to dilute to 500mL volumetric flask that contained 10 times dilution.
*July 10, 2013 by khadijah*

**Chemistry**

1. calculate the volume of concentrated HNO3 (68%)that is needed to prepare stock solution 0.25M in 1000mL volumetric flask. (density HNO3 = 1.513 g/cm^3) 2. from above stock solution, determine volume needed to dilute to 500mL volumetric flask that contained 10 times dilution.
*July 10, 2013 by Susan*

**Chemistry**

In a silphuric acid (H2SO4)-Sodium Hydroxide (NaOH) acid-base titration, 17.3mL of 0.126M NaOH is needed to neutralize 25mL of H2SO4 of unknown concentration. What is the morality of the H2SO4 solution? H2SO4 (aq)+ NaOH (aq) = Na2SO4 (aq) + H2O (l)
*July 1, 2014 by Dawn*

**Chemistry**

I posted this question on Thursday April 12 and received some help..but need more.. thanks Use the following information to identify element A and come pound B, then answer questions a and b. An empty glass container has a mass of 658.572 g. It has a mass of 659.452 g after it...
*April 16, 2007 by Julia*

**General Chemestry**

A galvanic (voltaic) cell consists of an electrode composed of chromium in a 1.0 M chromium(II) ion solution and another electrode composed of gold in a 1.0 M gold(III) ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 C.
*January 26, 2013 by Anonymous*

**chemistry**

A is a solution of HCL containing 7.30g/dm3.B is a solution ofX2CO3 containing 10.6g/dm3.assume that average volume of acid is 2.81cm3 and the volume of base is 25.00cm3.from your result and information .calculate (I)concentration of A in mol/dm3(ii)concentration of B in mol/...
*May 26, 2014 by john kelechi*

**Chemistry**

In an experiment liquid hexane, C6H14 (l) is combusted completely to produce CO2(g) and H2O (l) according to the equation: 2 C6H14 (l) + 19 O2(g) -> 12 CO2(g) + 14H2O (l) The change in H degrees for the reaction is -8.39 x 10^3 KJ. Calculate change in H degrees for C6H14 (l).
*November 29, 2010 by vvvvvv*

**Chemistry**

1.9 mol HCl and 3.8 mol NaOH react according to the equation HCl + NaOH −→ NaCl + H2O . Calculate the amount in moles of NaCl formed. Answer in units of mol
*February 9, 2012 by Mary*

**Chemistry**

Prepare a theoretical titration curve for titration of 25.0 mL of 0.1037 formic acid (HCOOH; pKa = 3.75) solution (diluted to 100 mL volume with deionized water) by 0.0964 M solution of KOH. I have to determine volume of KOH needed to reach equivalence point, the pH of ...
*March 5, 2012 by Clint*

**Calculating DHrxn?**

What is DHrxn for the following reaction, CH4(g) + 2 O2(g) ---> CO2(g) + 2 H2O(l), given DHf[CH4(g)] = -74.8 kJ; ...DHf[CO2(g)] = -393.5 kJ; ...DHf[H2O(l)] = -285.5 kJ. a. ) -604.2 kJ b. ) 869.7 kJ c. ) -997.7 kJ d. ) -889.7 kJ e. ) 997.7
*June 12, 2009 by AnthoniiEllis*

**chemistry**

1. the solubility of AgCl in water is 3.97x10^-6 at 0*C and 1.91X10^-4 at 100*C. calculate Ksp for AgCl at each temp. 2. using the data from #1 and the clausius- Clapeyron equation, calculate deltaH* and deltaS* for the formation of a saturated solution of AgCl. I just need ...
*March 28, 2011 by anonymous*

**math**

A lab needs a 20 liters of a 15% acid solution. The lab only has a 10% acid solution and a 30% acid solution. How much of the 10% acid solution will they need to mix with the 30% solution to obtain 20 liters of a 15% solution?
*April 2, 2013 by Anonymous*

**Chemistry**

Ethanol, C2H5OH or C2H6O, is mixed with gasoline and sold as gasohol. Given the following thermo-chemical reaction, calculate the kilograms (kg) of CO2 produced when enough ethanol is combusted to provide (or give off) 369 kJ of heat: C2H5OH (l) + 3 O2 (g) --> 2 CO2 (g) +3 ...
*July 12, 2011 by Robert*

**chemistry**

Given the thermochemical equation below, calculate the amount of energy released when 250. g of NaOH (molar mass = 40.0 g/mol) reacts with an excess of HCl. Report answer to the correct number of significant figures in units of kilojoules, kJ. NaOH + HCl --> NaCl + H2O ...
*April 25, 2013 by sarah*

**Chemistry**

The empirical formula for Brilliant Blie dye is C37 H34 N2 O9 S3 Na2, and the formula weight is 792.86 g/mol. How would you prepare a 4.73 X 10^-6 M solution of Brilliant Blue dye? How many grams of the dye do you need to add to a 1.00 L of water to make this solution? I have ...
*October 12, 2011 by Hannah*

**CHEMISTRY**

Calculate the H rxn for the following reaction. H f [H2S(g)] = -21 kJ/mol; H f [SO2(g)] = -297 kJ/mol; H f [H2O(l)] = -285.8 kJ/mol; 2H2S(g) + SO2(g) 3S(s) + 2H2O(l) a. 232.6 kJ b. 910 kJ c. -232.6 kJ d. -910 kJ
*August 22, 2010 by Lucinda*

**Chemistry**

write a balanced equation for the combustion of benzene. All hydrocarbons, like benzene are, are the same. Add O2. C goes to CO2 and H goes to H2O. C6H6 + O2 ==> CO2 + H2O I will let you balance it. Let me know if you have a problem with it. would it be... C6H6 + 14O2 -->...
*August 6, 2007 by Anonymous*

**math who me step by step**

25g of a sample of ferrous sulphate was dissolved in water containing dilute h2s04 and the volume made up to one litre. 25ml of this solution required 20ml of N/10 kmn04 solution for complete oxidation. Calculate the percentage of fes047h20 in the sample the right answer 88.96...
*January 1, 2014 by Fai*

**Math**

Alyssa is a chemist with Gemco Pharmaceutical Company. She needs to prepare 12 ounces of 9% hydrochloric acid solution. The only solution she currently has available are 4% and 12% hydrocholoric acid. How much should she use of each solution to obtain the needed solution.
*March 9, 2011 by John*

**College-Chemistry**

NaOH(s)+ H2SO4(aq)=Na2SO4(aq) + H2O(l) Consider the unbalanced equation above.A 0.900 g sample of impure NaOH was dissolved in water and required 37.0 mL of 0.145 M H2SO4 solution to react with the NaOH in the sample. What was the mass percent of NaOH in the sample?
*February 26, 2010 by Tiffany*

**Chenistry**

A 0.8870g sample of a mixture of nacl and kcl is dissolved in water and the solution is then treated with an excess of agn03 to yield 1.913g of agcl. Calculate the percentage by mass of nacl in the mixture 1.913g/ 143 = 0.0133 M agcl x/58 + Y/74 (0.887g-x) = 0.0133 Who helps ...
*January 19, 2014 by Carlos*

**Chemistry**

For each of the following unbalanced equations, suppose that exactly 15.0g of each reactant is taken. Determine which reactant is limiting, and calculate what mass of each product is expected. assume the limiting reactant is completely consumed. a)Al+HCL->AlCl3+H2 b)NaOH+...
*February 16, 2009 by Megan*

**Mass Transfer**

Solution of methanol and ethanol are substantially ideal. (a) Compute the vapour-liquid equilibria for this system at 1 and at 5 atm abs pressure, and plot xy and txy diagrams at each pressure (b) For each pressure compute relative volatilities , and determine an average value...
*April 8, 2014 by RHS*

**PhysicsPLEASE HELP**

i have a lab where we used VI method to calculate resistance of a LARGE resistor... circuit is as follows..(--- indicates wire) source---ammeter---resistor(voltmeter connected in parralel to resistor)---(connected back to source) the R value calculated was wrong. i need to ...
*February 9, 2010 by SAM*

**chemistry**

a mixture of methane and ethane is stored in a container at 294 mmHg. The gases are burned in air to form co2 and h2o. if the pressure of co2 is 357 mmhg measured at the same temperature and volume as the original mixture, calculate the mole fraction of the gases.
*December 4, 2010 by maggie*

**Chemistry**

A mixture of CuSO4 and CuSO45 H2O has a mass of 1.235 g. After heating to drive off all the water, the mass is only 0.830 g. What is the mass percent of CuSO45 H2O in the mixture?
*September 22, 2010 by Noelle*

**chemistry**

When 0.949 g of CaO is added to 200.0 mL of 0.500 M HCl(aq), a temperature increase of 389C is observed. Assume the solution's final volume is 200.0 mL, the density is 1.00 g/mL, and the heat capacity is 4.184 J/gC. what is molar heat of reaction, Hrxn, for the reaction of CaO...
*February 15, 2010 by blasting*

**Chemistry**

How do I find the molarity of NaCl for different dilutions? You calculate the number of moles per liter of solution.
*April 8, 2007 by Colleen*

**Chemistry**

Hydrogen cyanide is a weak acid with Ka = 4.9 x 10-10. Calculate the pH of a solution (to 2 decimal places) containing 2.28 g of Sr(CN)2 per 158 mL.
*January 7, 2008 by Andrew*

**chemistry**

calculate the number of grams of co2 that can be absorbed by complete reaction with a solution that contains 5.00 g of sodium hydroxide
*February 9, 2010 by Anonymous*

**Chemistry**

Can i please get a formula to calculate the concentration of an acid when it reacts with a standard solution? ( preferably 0.1 M NaOH and viniger )
*August 5, 2010 by Daniel*

**chemistry**

calculate the amount of solid NH4Cl to add to 50 mL of 1 M to form a mixture that has a pH of 9 assume no volume change in the solution
*October 6, 2010 by maycee*

**Chemistry **

Hi please help with this. You will mix 5 ml of each 2M HCL and 2M NaOH solutions, calculate the concentration of NaCl formed in the new solution?
*October 17, 2010 by John*

**chemistry**

calculate the molarity of 70.7g C2H6O in 2.25 L of solution, can someone walk me through this and provide the right answer? please and thank you =))
*December 3, 2010 by Jenni*

**Chemistry**

Calculate the Ksp Ca(OH)2 25cm3 of a saturated solution required 11.45cm3 of 0.1mol/dm3 HCl for neutralization.
*January 3, 2011 by Suha*

**chemistry**

Calculate the percent mass of a solution made by dissolving 25.2 of KBr into .250 liters of water.
*February 22, 2011 by yoda*

**chemistry**

0.1M solution of methanoic acid is found to have a ph of 2.4 at 25 degree celcius. Calculate the dissociation constant k at this temperature.
*March 26, 2011 by Olamide*

**chemistry**

Calculate the mass of silver nitrate needed to prepare a solution of concentration 0.01 moles per litre
*April 4, 2011 by Anonymous*

**Chemistry**

Calculate mass of silver nitrate needed to prepare a solution of concentration 0.01 moles per liter.
*April 5, 2011 by Slim Shady*

**Chem**

For a solution that is 0.280 M HC3H5O2 (propanoic acid Ka=1.3*10^-5) and 0.0894 M HI, calculate the following. Concentration of H30, OH, C3H5O2-, I-
*April 14, 2011 by Joe*

**Chemistry**

A 1.00 L solution saturated at 25C with lead(II) iodide contains 0.54 g of PbI2. Calculate the solubility-product constant for this salt at 25C. thanks
*April 27, 2011 by Rebekah*

**Chemistry II**

Calculate how many milliliters of 0.100 M HCl must be added to 25.0 ml of a 0.200 M solution of NH3 to prepare a buffer that has a pH of 9.50? Kb = 1.76 x 10^-5
*June 29, 2011 by Terence*

**Chemistry**

Calculate the molecular mass of sulphur if 35.5 g of sulphure dissolves in 1 00 g of CS2 to produce a solution that has a boiling point of 49.48 c.
*November 2, 2011 by Ethio*

**Cert III lab skills**

Explain how to calculate preparing 250.0ml of 1.25 mol/L solution of Na2CO3(aq)
*November 29, 2011 by lisa*

**AP Chemistry**

A solution is prepared by mixing 50.0 mL of 0.17 M Pb(NO3)2 with 50.0 mL of 1.6 M KCl. Calculate the concentrations of Pb2+ and Cl - at equilibrium. Ksp for PbCl2(s) is 1.6X 10-5.
*December 4, 2011 by Bill *

**Chemistry**

calculate the mass of silver nitrate present in 10mL of a 0.5M solution. will someone show me how to do this because i have no idea :(
*December 7, 2011 by Tabatha *

**chemistry**

how do i calculate the number of moles of ammonium iron (ll) sulphate (NH4)2 Fe(SO4)2.6H2O in 1dm3 of solution?
*December 30, 2011 by jevoy*

**Chem**

Calculate the volume of .300 M NaOH needed to prepare a pH=3.50 buffer with 250ml of .075M HF solution. pKa (HF) = 3.15
*February 11, 2012 by Will*

**Chemistry**

Calculate the freezing point depression of an aqueous solution prepared by mixing 22.0 g C6H12O6, with 600 ml of water
*February 20, 2012 by Kristen*

**AP CHEMISTRY**

A 1.00-L solution saturated at 25C with lead(II) iodide contains 0.54 g of PbI2. Calculate the solubility-product constant for this salt at 25C.
*March 3, 2012 by DAN*

**Chemistry help PLEASE!!**

For a solution that is 0.168 M NH3 and 0.104 M NH4Cl calculate the following.? [OH-] [NH4+] [Cl-] [H3O+] How would you do this :-/
*March 12, 2012 by Anonymous*

**chemistry**

calculate the ionisation constant of the conjugate base of a solution made from 0.20M HC2H3O2 AND 0.50M C2H302.
*March 31, 2012 by laze*

**Chemistry(Please help)**

Calculate the pH of an aqueous solution of 0.15 M potassium carbonate. I know that pH = -log(H30+) but I am not sure how to start this problem.
*April 14, 2012 by Hannah*

**Chemistry(Please help)**

Calculate the concentration of HC6H6O6- in an aqueous solution of 0.0851 M ascorbic acid, H2C6H6O6 (aq). I do not know how to start this
*April 15, 2012 by Hannah*

**college chemistry**

Followed by the total volume. Calculate the molarity of this solution: 0.521 mol NaCl;125 mL
*April 16, 2012 by michelle *

**Chem**

calculate the volume in ml of 0.250 M silver nitrate solution required to react completely with a 5.00 g piece of copper
*April 19, 2012 by No*

**Chem**

calculate the volume in ml of 0.250 M silver nitrate solution required to react completely with a 5.00 g piece of copper
*April 19, 2012 by No*

**chemistry**

how to Calculate the molarity of a solution if sulphuric acid contains 13%H2SO4 by mass and density is 1.02 gm per cm3.
*May 4, 2012 by hari*

**chemistry**

how to Calculate the molarity of a solution if sulphuric acid contains 13%H2SO4 by mass and density is 1.02 gm per cm3.
*May 4, 2012 by hari*

**Chemistry**

Pb(NO3)2(aq) + NaSO4(aq) → PbSO4(s)+ 2NaNO3(aq) Identify the ions that are present in each solution, and calculate their concentrations.
*May 16, 2012 by Sam*

**Chem 2**

Using the reaction HB<=> H+ + B- and the Ka for that expression, calculate the Ka given the initial concentration of weak acid to be 0.150 M and the pH of the solution to be 2.79.
*July 27, 2012 by Myssey*

**chemistry**

A solution is prepared by mixing 50.7 mL of 0.28 M Pb(NO3)2 with 70.8 mL of 1.0 M KCl. Calculate the concentrations of Pb2+ and Cl - at equilibrium. Ksp for PbCl2(s) is 1.6 10-5.
*February 21, 2013 by jeff*

**Chemistry**

Calculate the percent ionization of 0.140 M lactic acid in a solution containing 8.510−3 M sodium lactate.
*April 27, 2013 by John*

**Chemistry 12**

Calculate the volume of 12 M Na2SO3 which needs to be added to 500.0 mL of water in order to produce a solution in which [Na+]= 0.200 M.
*October 8, 2013 by Riann*

**chemistry**

A 200.0mL solution with 3.1 x 10^-3 mol of MA will begin to precipitate at 19.4 C. Calculate each of the following at this temperature. a) Ksp b)change in G
*April 13, 2014 by KAMILAH*

**chemistry**

50.0cm^3 of 2.0 mol dm^-3 aluminium sulphate,Al2(SO4)3 solution Calculate the number of moles of ions.
*May 7, 2014 by mandy*

**Chemistry 12**

calculate the Ph of a solution composed of 0.75 grams of KOH dissolved in 500ml of water. assume total ionization.
*June 27, 2014 by jeremy *

**chemistry**

3. When a mixture of 10.0 grams of acetylene (C2H2) and 10.0 grams of oxygen (O2) is ignited, the resulting combustion reaction produces CO2 and H2O. A) Write a balanced equation for this reaction. B) What is the limiting reactant? C) How many grams of C2, H2, O2, CO2, and H2O...
*May 14, 2013 by tra*

**Chemistry**

Consider the following buffer equilibrium: HF (high concentration) + H2O <--> H3O+ (low concentration) + F- ( high concentration) Using Le Chatelier's Principle, explain what happens to the pH of the buffer solution when a small amount of NaOH is added. Wouldn't OH- ...
*June 3, 2010 by sh*

**statistics**

an auditor wishes to test the assumption that the mean value of all accounts receivable in a given firm is $260.00 she will reject this claim only if it is clearly contradicted by the sample mean. the sample standard deviation of 36 accounts is $43, the sample mean is $250, ...
*April 29, 2012 by b*

**CHEMISTRY**

A 21g SAMPLE OF SULFURIC ACID IS DISSOLVED COMPLETELY IN SUFFICIENT WATER TO MAKE A .025 LITRE OF FINAL SOLUTION. CALCULATE THE HYDROGEN ION CONCENTRATION (IN mol1-1)IN THIS SOLUTION. GIVE YOUR ANSWER IN SCIENTIFIC NOTATION TO AN APPROPRIATE NUMBER OF SIG. FIGS. SHOW THE ...
*March 8, 2007 by Desmond*

**Chemistry**

a solution is prepared using .015 L of 1.0 M HCl and .020 L of .50 M HNO3. the final volume of the solution is 1.25 L. Answer th following questions. a)what are the [H3O+] and [OH-] in the final solution? b)What is the pH of the final solution?
*May 4, 2010 by Alexa*

**Chemistry**

A galvanic (voltaic) cell consists of an electrode composed of magnesium in a 1.0 M magnesium ion solution and another electrode composed of copper in a 1.0 M copper(I) ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 dC.
*April 1, 2013 by Anon*

**chemistry**

The following reaction was carried out in a 2.00 reaction vessel at 1100 : C+H2O -> C)+H2 If during the course of the reaction, the vessel is found to contain 7.00mol of C, 13.3mol of H2o, 3.80mol of CO, and 7.20mol of H2, what is the reaction quotient ? Enter the reaction ...
*April 28, 2013 by JAclyn clark*

**math**

14.what value of n will result in a mean if 31 15.what value of n will result in a median of 23 15.what value of a will result in a range of 84 14,46,19,10,39,22,24,77,n Refresh your memory about the defnition of median, mode and range of a set of numbers. Then pick a value of...
*March 4, 2007 by alice*

**math**

Given that g(x)= 2x+1/5 and f(x)=x+4 Calculate the value of g(-2) 2(-2)+1/5= -3/5 Is this right?? How do i write an expression for gf(x) in the simpliest form?? And how do i find inverse functions such as g`1(x)?
*June 30, 2009 by Maxine*

**Finance**

How do I calculate a present value? 7,000 in 5 years at a quarterly discount rate of 6% I have looked at the material, but I am confused. Thank you
*April 22, 2011 by Nancy*

**Chemistry**

What is the value of the rate constant at 17 degrees celsius? The Ea = 122 kJ/mol I know I have to use ln k = ln A - Ea/RT.. but I don't know how to calculate it without known ln A and how do you find ln A Thank you for your help!
*February 6, 2012 by Vicky*

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