Wednesday

April 16, 2014

April 16, 2014

Number of results: 34,215

**chemistry**

A sample of orange juice has a pH of 3.44. Its [H3O+] is
*Wednesday, October 24, 2012 at 10:34am by Anonymous*

**Chemistry**

2^3 = 8 So 1/8 of the sample will remain. 1/8 x 100 = 12.5g remaining.
*Thursday, January 24, 2013 at 9:17pm by DrBob222*

**Chemistry**

a sample of silver chromate has a mass of 78.6 grams?
*Monday, January 28, 2013 at 12:07pm by david*

**science**

a 15-g sample of a material has a volume of 1.3cc. what is its density
*Wednesday, February 13, 2013 at 3:02am by Anonymous*

**chemistry**

Is 1.00 L the sample? mols Au = 1.50E17/6.02E23 = ?
*Thursday, April 25, 2013 at 6:19pm by DrBob222*

**Stats**

NEVERMIND. I figured it out Sample is neither C nor B....It is D
*Tuesday, June 11, 2013 at 5:58pm by mysterychicken*

**Chemistry**

How many moles of iron atoms does a 27 g sample contain?
*Sunday, June 30, 2013 at 11:19pm by RAID*

**statistics (?)**

No sample data given. Z = (score-mean)/SD
*Sunday, January 19, 2014 at 11:24pm by PsyDAG*

**Math**

Find the mean (∑x/n) for your sample and multiply by 150.
*Monday, February 3, 2014 at 4:18am by PsyDAG*

**statistics (?)**

Data lacking. What are the mean, standard deviation and n for the sample?
*Thursday, February 6, 2014 at 9:58pm by PsyDAG*

**math**

population is 6,000 batches sample is batch examined
*Monday, March 3, 2014 at 1:11pm by Damon*

**statistics**

A student union wants to obtain a 90% confidence interval for the proportion of “full time” students who hold a part-time job for 20 hours or more per week. For this purpose, they want to interview a sample of full-time students. They want a margin of error to be at most 0.1, ...
*Friday, December 20, 2013 at 12:33pm by Steven *

**AP CHEM**

Please help me with thses AP CHEM homework problems and show the steps to how to find the solutions: Solid Liquid Titrations: Determine the concentration of the indicated liquid unknown given the mass of a solid standard and the buret data for the titration. #35) What is the ...
*Thursday, July 31, 2008 at 10:50am by shylo*

**statistics**

An animal trainer obtained the following sample data (Table A) in a study of reaction times of dogs (in seconds) to a specific stimulus. He then selected another group of dogs that were much older than the first group and measure their reaction times to the same stimulus. The ...
*Friday, October 16, 2009 at 2:34pm by Anonymous*

**Chemistry**

Question: you have .420 Litters of a solution containing Ag3PO4 (s) in equilibrium with its ions. write an algebraic equation which when solved will geive the molar concentration of Ag^+1 after the addition of .200 moles of Na3Po4(s) to the .420 liters of solution. in your ...
*Monday, May 11, 2009 at 11:44pm by Eliz*

**chemistry**

a galvanic cell: A copper electrode is placed in a Cu(NO3)2 electrolyte. An iron electrode is placed in a Fe(NO3)3 electrolyte. a) What will happen to the voltage if sodium sulfide solution was added to the copper solution(I found that CuS(solid precipitate) will be formed, ...
*Sunday, February 21, 2010 at 1:37pm by LALA*

**chemistry**

i need some help with this i dont even know where to begin A solution of 62.4 g of insulin in enough water to make 1.000 L of solution has an osmotic pressure of 0.305 atm at 25°C. Based on these data, what is the molar mass (MW) of insulin (g/mol)? (Which is the best answer ...
*Tuesday, May 1, 2007 at 12:46am by Anonymous*

**Spanish Persausive Essay**

Identify a problem that involves the Spanish language in some way. Your choice! (Example: Unfairness/bias issues in highstakes testing for ESL students) Propose a solution to the problem. And then support and develope your solution into a persuasive writing piece. (Doesn't ...
*Sunday, March 15, 2009 at 10:31am by Holly*

**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 ...
*Monday, March 5, 2012 at 6:10pm by Clint*

**chemistry**

what mass of barium sulphate can be produced when 100.0 ml of a 0.100M solution of barium chloride is mixed with 100.0 ml of a 0.100M solution of Iron(lll) sulphate?
*Sunday, November 20, 2011 at 11:02am by NONO*

**Alg 1**

Find the exact solution for each equaton. Find the approximate solution to the nearest tenth. 3 sq rt 3/sq rt 1 + sq rt 1 = x/sq rt 3 Please solve and explain. Thanks
*Wednesday, April 3, 2013 at 2:07pm by Jane*

**statistics**

A nutritionist studying weight gain for college freshmen obtains a sample of n = 20 first year student at the state college. Each student is weighed on the first day of school an again on the last day of the semester. The following scores measure the change in weight, in ...
*Sunday, June 9, 2013 at 6:09pm by Tami*

**PHYSICAL SCIENCE**

Try some of the density worksheets: http://search.yahoo.com/search?fr=mcafee&p=density+of+a+sample+of+zinc+that+has+a+mass+of+48+kilograms+and+a+volume+of+7.5+mL.+ Sra
*Wednesday, October 5, 2011 at 9:59am by SraJMcGin*

**physics :thinking check please**

I think that: psi= A sin kx; is a solution to Schrodinger's time independent eqn for a particle confined: a) within an infinite pot well, and b) within the walls of a finite well;but psi= B exp(-kx) would only be a solution for outside the walls of a finite well. Am I close? ...
*Thursday, April 30, 2009 at 3:05pm by charlie*

**Chemistry**

the following questions are about colligative properties: a)How much would the freezing point change in a 2.5 solution of phenol in benzene? b)how much would the boiling point change in a 1.m solution of magnesium chloride in ethanol? c)Does adding sugar to water raise or ...
*Sunday, May 2, 2010 at 11:33pm by Kim*

**Chemistry**

A solution may conain the ions Ba^2+, Ag^+, and Cu2+. Add sodium chloride and get a white predipitate. The supernatant is decanted, potassium sulfate solution is added to the supernatant and no reaction is observed. Add sodium hydroxide and get a blue solid. Which ions are ...
*Wednesday, May 5, 2010 at 9:35pm by Mary*

**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...
*Wednesday, December 15, 2010 at 8:18pm by John*

**physics**

Define STPD, ATPD, BTPS and list the values. I'm in college and our books haven't came in from the bookstore. I don't understand how the prof. is still making us do this HW. my younger brother told me I should try to get help from this site since it helped him. This is all I ...
*Sunday, January 27, 2008 at 5:46pm by jamie*

**CHemistry Please Help..............LAB**

Standardization of the Sodium Thiosulfate Solution Make up a standard solution of potassium iodate by accurately “weighing by difference” about 0.1 g of KIO3 and placing it in your 100 mL volumetric flask. Fill the flask to mark with distilled water. Potassium iodate reacts ...
*Sunday, October 19, 2008 at 3:28pm by Sara*

**chem**

I actually figured out how to do that one. but i have another one Question Part Points Submissions Used 1 –/1 0/4 Total –/1 .This question has some parts which are scored using special conditions. Question Part 1: A deduction of 10% of the points for this question will be ...
*Sunday, April 28, 2013 at 4:42pm by sarah*

**physics**

A volume Vi = 23.1 L of air at temperature T = 21 ¢XC is compressed at constant temperature to a volume Vf = 7.7 L. The relative humidity of the air before compression is R = 56.4 %. Saturated water vapour in air at this temperature has a vapour pressure vp = 2.5 kPa and a ...
*Tuesday, March 29, 2011 at 12:11am by Sarah*

**Chem**

Would you please tell me if these are right? A sample of helium has a volume of 325 ml and a pressure of 655 mm hg. What will be the pressure if the helium is compressed to 125 ml (t and n are constant) I got 1703 mm of Hg A 75.0 ml sample of oxygen has a pressure of 1.50 atm...
*Saturday, October 23, 2010 at 8:42pm by Jason*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*Saturday, November 30, 2013 at 1:50am by Katy*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*Friday, November 29, 2013 at 7:30pm by Katy*

**Probability and Statistics**

The proportion of adults living in a small town who are college graduates is estimated to be p = 0.6. To test this hypothesis, a random sample of 15 adults is selected. If the number of college graduates in the sample is anywhere from 6 to 12, we shall not reject the null ...
*Saturday, November 30, 2013 at 8:06pm by Katy*

**ALGEBRA/EQUATION**

When we have a system of linear equations, it can fall into one of three cases: 1. no solution, 2. a unique solution, and 3. an infinite number of solutions. I am not sure which level of linear algebra you are working on, but I will explain it in the easiest terms: 1. happens ...
*Tuesday, December 14, 2010 at 6:40pm by MathMate*

**Chemistry**

Write the chemical formula for the simplest heptane isomer and give its name, b) give the names of two heptane isomers with hexane as the base chain, c) give the names of names of the five heptane isomers with pentane as the base chain, d) give the name of the isomer with ...
*Saturday, March 24, 2012 at 11:52am by Hannah*

**Chemistry**

I calculated the M of NaBO.... at 6.59x10^-3 for the mass I measured. I have a chart of measurements where I used 9.98mL out of 100mL of solution that I made. I was given the equation (mass Na.../molar mass Na...)*(volume Na.../volume total solution) the balanced equation I'm ...
*Saturday, March 17, 2012 at 8:47pm by Sheena*

**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
*Monday, January 21, 2013 at 7:08am by Samantha*

**chem**

If 20.5 mL of a 5.256 M solution of benzoic acid is used in an experiment similar to experiment 4, how many grams of benzoic acid is in the starting solution? (molar mass of benzoic acid = 122.12 g/mol) Be sure to pay attention to significant figures. The answers are all in ...
*Monday, February 4, 2013 at 12:41am by alice*

**Chemistry, pH, Buffers**

Please help!! Given this data: mass of unknown acid 1.4671g Volume of NaOH used in titration 18.47mL Concentration of the NaOH used 0.2403M pH of the original acid solution 2.16 pH of the final acid solution 3.49 Show me how do I calculate the Ka of the unknown acid and the ...
*Monday, April 2, 2012 at 11:44am by Krina*

**CHEMISTRY**

Yes it does. From the problem, it says that 50 cm^3 of AgNO3 and 50 cm^3 of HCl are mixed. Therefore, the total volume of the solution is 50 + 50 = 100 cm^3. Then an assumption is that the density of the solution is 1 g/ cm^3. We have the volume, we have the density, we can ...
*Tuesday, November 12, 2013 at 10:31pm by Jai*

**chemistry**

A solution containing silver (I) ion (an oxidizing agent) is mixed with a solution containing iron (II) ion (a reducing agent). a. What is the balanced equation? b. If the contents of the reaction mixture described above are filtered, what substances, if any, would remain on ...
*Friday, January 1, 2010 at 7:00pm by anonymous*

**chemistry**

A solution containing silver (I) ion (an oxidizing agent) is mixed with a solution containing iron (II) ion (a reducing agent). a. What is the balanced equation? b. If the contents of the reaction mixture described above are filtered, what substances, if any, would remain on ...
*Friday, January 1, 2010 at 7:20pm by anonymous*

**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 ...
*Wednesday, January 25, 2012 at 6:54pm by Lucas*

**chemistry help!!! (clueless)**

1. Consider the conductance meter and the titration method of determining the salt content of a brine sample. Discuss at least two advantages and two disadvantages of each method. 2. A corrosion technologist pipetted a 50.00 mL sample of an unknown brine and titrated it with ...
*Monday, June 19, 2006 at 5:26pm by lightning*

**Chemistry**

First some house cleaning. 1. Its CuSO4 and not CUSO4. 2. I presume your use of clear means it is colorless. There is no such color as clear. Colorless means it has no color. Clear means it is not turbid. A solution can be blue and clear or blue and turbid or colorless and ...
*Wednesday, October 8, 2008 at 10:48pm by DrBob222*

**science**

Are you asking molarity and molality? Molarity is #mols/L of solution. Molality is #mols/kg of solution.
*Thursday, August 30, 2007 at 9:32pm by DrBob222*

**Math**

The number of dry cleaning orders picked up at Sunny Fresh Dry Cleaners was sampled over 12 hour periods. Below is the sample: 142 171 125 91 140 125 97 125 162 142 125 117 89 125 140 128 From this data set, compute the sample mean, median, mode and midrange. Compute the 1st ...
*Saturday, July 30, 2011 at 2:55pm by Jen*

**Chemistry College (Need to know!)**

How is this Possible GK. Everywhere I have looked, including mark schemes and chemistry websites dH(solution) is worked out via this equation: dH(solution) = dH(LE) - dH(hyd) + dH(hyd) What is it you are working out with solute and solvent?
*Thursday, June 11, 2009 at 5:18pm by Ben*

**MATH Statistics**

A student union wants to obtain a 90% confidence interval for the proportion of “full time” students who hold a part-time job for 20 hours or more per week. For this purpose, they want to interview a sample of full-time students. They want a margin of error to be at most 0.1, ...
*Friday, December 20, 2013 at 1:07am by Steven *

**chemistry**

What will be the final pH value if you mix 50ml HCl (aqueous solution, pH=0.5) and 40ml NaOH (aqueous solution, pH=12). Hint: convert pH value to concentration of acids/base, then consider the neutralization reaction, then find out the resulting pH value. Please show me your ...
*Thursday, April 4, 2013 at 11:44am by Anonymous*

**Chemistry again**

Chromium is ametal that is added to steel to improve its resitance to corrosion. Calculate both the number of miles in a sample of Cr containing 5.00 x 10^20 atms and the mass of the sample. Ok this is how I worked it. 1 mole of Cr = 51.996g = 6.022 x 10^23 atoms (whatever ...
*Tuesday, January 6, 2009 at 9:36pm by Chopsticks*

**Chemistry;HELP**

Use the 5-step method and be sure to include units where appropriate. Round your answers to the correct number of significant digits. Mass m Density = -------------- or D = ------ Volume v Adjust the density formula and solve the problems below: m D = ------- Original Formula...
*Wednesday, January 16, 2013 at 2:32pm by Victoria*

**chemisty**

A nitric acid solution is neutralized using sodium hydroxide. How many grams of sodium hydroxide are needed to neutralize 5.50 L of 1.200 M nitric acid solution? HNO3 (aq) + NaOH (aq) → H2O (l) + NaNO3 (aq)
*Wednesday, December 1, 2010 at 2:14pm by silent*

**Chemistry**

Calculate the solid needed to make a 250ml solution that is 0.34M in sodium cation, using sodium sulfate decahydrate. I came up with 13.685g. but how do I make that into 250ml of a solution that is0.34M in sodium cation?
*Thursday, October 27, 2011 at 9:41pm by Denise*

**chemistry**

The pKb of ammonia solution, NH3(aq) is 4.76. A buffer solution contains NH4Cl and NH3, has a pH of 9.45, and a total ammonia concentration (all forms) of 0.400 M. What is the concentration of NH4+? (Hint: [NH4+] + [NH3] = 0.400 M)
*Monday, May 6, 2013 at 10:37am by Anonymous*

**chemistry**

You need to be aware of the definitions. I can get you started. For A, remember the definition of % by mass is (mass solute/mass soln)*100 = % w/w. Therefore, you have 10 g H2SO4/100 g solution. You want to know how many g H2SO4 are in 50 g of this solution. Of course that's ...
*Sunday, April 7, 2013 at 10:58pm by DrBob222*

**Algebra II**

Solve: 3+2(1-x) >6 or 2x+14 <=8. Graph the solution set on a number line. When I solved the equations for the first one I got x<-1/2 and for the second one I got x<= -3. How do I graph the solution set for these????
*Saturday, January 5, 2008 at 5:54pm by Lucy*

**Algebra **

draw a vertical line at x=6. The solution then so far is all the area to the right. Now draw a horizontal line at y=-5. The solution now is anything above y=-5. Now look at the combined overlapping allowed areas, to the right of x=6, and above y=-5
*Saturday, October 10, 2009 at 1:00am by bobpursley*

**algebra **

Which has a Unique solution, No solution, or infinitely many solutions? 1. 2X + 3 = 9 2. 9X+ 2 = 9X+ 2 3. (1/2X+3) = (1/3x+9) 4. (x+2)(x+3) = x*x (x squared) + 5x + 6 5. 2(2x+3) = 4x+6 my guess is 1. unique 2. no 3. unique 4. unique 5. infinite 6. infinte but I know at least ...
*Thursday, September 16, 2010 at 10:29pm by Pam*

**math**

150 lb= 150/2.2 kg= you do it. in each liter of solution, you have 150grams mannitol you need 1.5*150/2.2 grams in 1 liter, you get 150 grams (15 percent solution) so volume in liters= 1.5*150/2.2*1/150 volume in ml= 1500/2.2=681ml =
*Thursday, February 2, 2012 at 5:02pm by bobpursley*

**math, help**

What are two solutions for 3x-y=0 am i correct on this inorder to graph (0,0) and (2,6) Because the line goes through (0,0) so how do i get two solutions from that line? You can get two solutions from that line because the first solution (0,0) is from the start of the axons x,...
*Saturday, February 10, 2007 at 12:27pm by jasmine20*

**math**

Area= width*height Lets just do one side. area= x*2cosX darea/dx= 2x*2cosx- 2x^2sinx=0 4xcosx=2x^2 sinX 2= x tanx I get a graphical solution very near PI/3, -PI/3, so sthe base is 2PI/3 I cant find an exact solution. Check my work.
*Wednesday, December 9, 2009 at 8:07pm by bobpursley*

**chemistry**

Two aqueous solutions of sucrose, C12H22O12, are mixed. One solution is 0.1495 M sucrose and has d = 1.018 g/mL; the other is 12.00 sucrose by mass and has d = 1.038 g/ml. Calculate the moles C12H22O12 percent in the mixed solution. Please provide steps (assume volume is same ...
*Wednesday, February 17, 2010 at 6:59am by anonymous*

**chemistry**

Two aqueous solutions of sucrose, C12H22O12, are mixed. One solution is 0.1495 M sucrose and has d = 1.018 g/mL; the other is 12.00 % sucrose by mass and has d = 1.038 g/ml. Calculate the moles C12H22O12 percent in the mixed solution. Please provide steps (assume volume is ...
*Wednesday, February 17, 2010 at 3:15pm by anonymous*

**MAths**

Consider the following system of inequalities: (c−1)x^2+2cx+c+4≤0 ---- (1) cx^2+2(c+1)x+(c+1)≥0 ---- (2) The sum of all real values of c, such that the system has a unique solution, can be written as a/b, where a and b are coprime positive integers. What is ...
*Monday, April 29, 2013 at 4:20am by ianian*

**algebra**

Consider the following system of inequalities: {(c-1)x^2+2cx+c+4<0 { cx^2 + 2(c+1)x+(c+1)>0 The sum of all real values of c, such that the system has a unique solution, can be written as ab, where a and b are coprime positive integers. What is the value of a+b? Details ...
*Monday, April 29, 2013 at 11:46am by hmmm*

**functions 12**

x^4 -3x^3 -25 x^2 -21 x = 0 x ( x^3 -3 x^2 -25 x -21) = 0 so we know x = 0 is a solution Guess -1 solution (You can see that x^3 -3 x^2 -25 x -21 is 0 for x = -1) then we know (x+1) is a factor of x^3 -3 x^2 -25 x -21 so do long division (x^3 -3 x^2 -25 x -21)/(x+1) = x^2-4x-...
*Saturday, October 22, 2011 at 7:17pm by Damon*

**Chemistry**

A strip of zinc metal was placed in a beaker that contained 120mL of a solution of copper(2) nitrate, Cu(NO3)2(aq). The mass of the copper produced was 0.813g. Find the initial concentration of the solution of copper(2)nitrate. Can u help me out with making the balanced ...
*Tuesday, March 5, 2013 at 8:15pm by Kristien*

**OChem**

I can't draw a graph but I can describe how to do it. ____________ | | | |____________ Now turn this counter clockwise 90 degrees so it looks almost like a U (looks like this, |_|, but on a larger scale.) Place 1.3330 on the left Y axis and 1.3610 on the right Y axis, then ...
*Wednesday, October 26, 2011 at 12:53am by DrBob222*

**Chemistry**

What is the mole fraction of methanol CH3OH, in the vapor phase from a solution consisting of a mixture of methanol and propanol CH3CH2CH2OH at 40celsius, if the total pressure above the solution is 131 torr? The vapor pressures of methanol and propanolare 303 and 44.60 torr ...
*Saturday, April 23, 2011 at 4:50pm by Jude*

**Math 3**

Solve by factoring: One of the solutions to the quadratic equation x^2 - 13x + 30 is 3. What is the other solution? Is it:(x+3) If 3 is a solution, then the quadratic contains a factor (x-3). The other factor is thus (x-10), and it follows that the other root is x = 10. thanks...
*Tuesday, January 30, 2007 at 5:30pm by Margie*

**Science repost for iiii**

science - iiii, Monday, October 29, 2007 at 8:08pm What test would you need to perform to prove that it is the combination of glucose and the Glucose Indicator Solution that changes color when heated and not just the glucose or the Glucose Indicator Solution alone? Support ...
*Monday, October 29, 2007 at 8:13pm by Ms. Sue*

**science**

Q4.you will be asked to prepare 25.0 mL of a 0.019 M solution of sodium chloride during this experiment.... a.calculate mass of sodium chloride needed to prepare solution. (0.25L)(0.019M NaCl/L)*(58.5g NaCl/1mole NaCl)=0.278 g NaCl....is that right? someone just replied it was...
*Thursday, September 17, 2009 at 6:08pm by Ally*

**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 ...
*Wednesday, January 20, 2010 at 1:14am by bubble*

**CHEMISTRY..please help..thanks**

Calculate the new molarity if each of the following dilutions is made. Assume the volumes are additive. (a) 52.3 mL of water is added to 27.1 mL of 0.124 M KOH solution (b) 110. mL of water is added to 54.2 mL of 0.808 M NaCl solution ((please show work, thank u so much)
*Wednesday, November 10, 2010 at 3:35am by Jasmin*

**Chemistry**

The mass of the solution will change as a result of the newly added substance. Because of colligative properties, anytime something is added to solution, the freezing point is lowered and the boiling point is raised. Water does not conduct electricity on its own, and since ...
*Wednesday, February 23, 2011 at 10:55pm by Emily*

**Math 7th Grade**

A car cost $65 per day to rent plus $.35 per mile. Joe rents car for 1 day and drives 115 miles. what is the equation and the solution. The solution is pretty simple $65 + .35x115 = 105.25 I can't figure out the equation.
*Monday, March 12, 2012 at 10:38pm by Chris*

**pre-calculus**

solve the logarithmic equation. be sure to reject any value of x that is not in the domain of the orginal logarithmic expression. In square root of x+2=2 (If I try to make the square root sign it will not come out right so I wrote it out instead) What is the exact solution. A...
*Saturday, October 6, 2012 at 3:19pm by ladybug*

**Chemistry**

Calculate the volume of 2.503 N HNO3 added to 100 mL of HCl in order to prepare 1.1251 N acid solution from the following data: 58.96 mL NaOH will neutralize 2.521g of potassium tetroxalate and 45.57 mL of HCl will neutralize 53.0 mL of the NaOH solution.
*Tuesday, January 21, 2014 at 3:11am by Summer*

**Chemsitry**

Starting out with 50 mL of 0.20 M NaHCO3, calculate how many mL of 0.50 M NaOH solution to add to make 100 mL of approximately 0.10 M (total) buffer solution with a pH of 10.35. By adding NaOH, some of the NaHCO3 gets converted to the conjugate Na2CO3. This conjugate acid/base...
*Monday, April 2, 2012 at 11:39pm by Cassandra*

**chemistry**

Two aqueous solutions of sucrose, C12H22O12, are mixed. One solution is 0.1495 M sucrose and has d = 1.018 g/mL; the other is 12.00 % sucrose by mass and has d = 1.038 g/ml. Calculate the moles C12H22O12 percent in the mixed solution. Please provide steps 100 mL for each soln.
*Wednesday, February 17, 2010 at 7:36pm by anonymous*

**Chem**

Suppose solute A has a distribution coefficient of 1.0 between water and diethyl ether. Demonstrate that of 100mL of a solution of 5.0g of A in water were extracted with two 25-mL portions of ether, a smaller amount of A would remain in the water than if the solution were ...
*Wednesday, May 5, 2010 at 3:41am by Anonymous*

**PH Calculation**

Consider a 0.42 M solution of NaCH3COO CH3COO–(aq) + H2O(l) -> CH3COOH(aq) + OH–(aq) Calculate the pH of the solution at equilibrium. Try the weak acid or weak base approximation (as appropriate) and check the validity of the approximation. If the approximation is not valid...
*Thursday, April 26, 2012 at 2:41am by RZeal*

**Chemistry**

When 5.00 g of NaOH(s) are added to 100 g of water using a calorimeter, the temperature rises from 25.0 to 37.5 °C. Calculate the molar heat of solution. NaOH(s)--->Na(aq)+OH(aq) Assume that the specific heat capacity of water is 4.18 J/gK and that of the NaOH(aq) solution ...
*Wednesday, November 14, 2012 at 9:08pm by FIrst_lady*

**chem.**

Acetic acid is CH3COOH (HC2H3O2). Its the right end H that is acidic. CH3COOH + NaOH ==> CH3COONa + HOH mols NaOH required = M x L = ?? mols acetic acid must be the same since the reaction is 1 mol CH3COOH to 1 mol NaOH. Molarity CH3OOH = # mols/L = mols/0.10 = xx. For ...
*Friday, March 7, 2008 at 12:33pm by DrBob222*

**Chemistry**

Question: Suppose you have 557 ml of 0.0300M HCL and you want to make up a solution of HCL that has a pH of 1.831. What is the maximum volume (in liters) that you can make of this solution? I know that you can get the concentration of HCL using the pH given, but how do you ...
*Tuesday, March 3, 2009 at 10:05pm by eliz*

**college Chemistry**

A 21.18 mL of 0.250 M NaOH is titrated with a H2SO4 solution. The initial volume of H2SO4 was 13.28 and the final volume of H2SO4 was 28.29 mL when the solution turned very slightly pink. What is the concentration of NaOH?
*Monday, December 6, 2010 at 4:04pm by Ivy*

**Chemistry Help Pls!!!**

A 21.18 mL of 0.250 M NaOH is titrated with a H2SO4 solution. The initial volume of H2SO4 was 13.28 and the final volume of H2SO4 was 28.29 mL when the solution turned very slightly pink. What is the concentration of NaOH?
*Monday, December 6, 2010 at 9:11pm by Jerome*

**college Chemistry**

A 21.18 mL of 0.250 M NaOH is titrated with a H2SO4 solution. The initial volume of H2SO4 was 13.28 and the final volume of H2SO4 was 28.29 mL when the solution turned very slightly pink. What is the concentration of NaOH?
*Tuesday, December 7, 2010 at 12:19am by Ivy*

**Chemistry**

Consider the following chemical reaction 2HCL+ Ca(OH)2 CaCl2+2H2O You have mixed 30.00ml of 0.150 M HCl solution with 20.00ml of 0.100m Ca(OH)2 solution what is the molarity of the HCl, Ca( OH)2 and CaCl2 after the reaction has stopped
*Tuesday, December 3, 2013 at 8:37pm by Ruffles*

**calculus**

Let there be x mL of 65% solution and y mL of 25% solution. x + y = 384 Amount of acid: 0.50*384 = 192 = 0.65 x + 0.25 y 768 = 2.6 x + y Subtract the first equation from the third. 1.6 x = 384 x = 240 mL y = 144 mL
*Friday, January 22, 2010 at 1:29am by drwls*

**6th grade**

Mix sand and sugar with water and heat the solution. the sugar dissolves and sand is left behind. filter and separate sand. Now heat the sugar solution, until water evaporates and sugar crystallises.
*Monday, October 11, 2010 at 9:40pm by Anonymous*

**Statistics**

Check my answers please! Thanks a lot. Five students reported that the previous night they slept: 7,8,7,10,9 hours. Calculate the sample varience and standard deviation. sample varience = 1346.5 standard deviation = 36.7 Consider this. Ths standard deviation can never be ...
*Thursday, February 1, 2007 at 12:35pm by Jake*

**Algebra II**

If (-1+2i) is a solution, its complex conjugate (-1-2i) must be a solution. In other words x = -1+2i x = -1-2i are solutions so x+1-2iand x+1+2i are both factors so their product should be a factor I get x^2+2x+5 now do your division I get x^2-2x-1 well that is (x-1)(x-1) so ...
*Thursday, December 13, 2007 at 7:41pm by Damon*

**statistics**

Use a) for your hypotheses. You can try a proportional one-sample z-test since this problem is using proportions. Using a formula for a proportional one-sample z-test with your data included, we have: z = .16 - .15 -->test value (150/940) is .16) minus population value (.15...
*Monday, December 10, 2012 at 3:57pm by MathGuru*

**BIOLOGY/CHEMISTY**

a student uses the unduiluted glucose stock solution in a reaction and finds that the absorbance values over 90 seceonds are all 1.900. What does this result tell you abou the enzyme activity of glucose oxidase in this reaction after the 90 seconds time point? Would it be ...
*Sunday, October 28, 2012 at 11:33pm by Debbie*

**Chemistry**

In a constant-pressure calorimeter, 65.0 mL of 0.330 M Ba(OH)2 was added to 65.0 mL of 0.660 M HCl. The reaction caused the temperature of the solution to rise from 23.85 °C to 28.35 °C. If the solution has the same density and specific heat as water, what is ΔH for this ...
*Tuesday, October 22, 2013 at 6:13pm by Nate *

**Chemistry**

A 100g sample of water at 90 degrees celsius is added to a 100g sample of water at 10 degrees celsius. The final temperature of the water is which of the following: a) between 50 degrees celsius and 90 degrees celsius b) 50 degrees celsius c) between 10 degrees celsius This is...
*Sunday, November 13, 2011 at 8:47pm by Shellby*

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