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April 27, 2015

Search: NaOH

Number of results: 3,145

AP CHEM
Hello, I'm working these homework questions out; however it is a series of questions and without one step correctly completed, it's nearly impossible to get the others. I posted my work and commented where I need assistance. Thank you so much in advance!!! Potassium hydrogen ...
April 17, 2008 by Sigurd

CHEMISTRY
1) An NaOH solution of unknown concentration is titrated with HCl. 51.9 mL of 0.400 mol/L HCl will neutralize 75.0 mL of the NaOH. What is the concentration of the NaOH solution ? Record your answer in decimal notation. I think the answer is 0.277 mol/L. is that right? 2)An ...
January 31, 2012 by TIANDRA

chem
Quantitative analysis of soda ash by double indicator *why there is a need to boil distilled water in the preparation of base solutions? *why a mixture of NaOH and NaHCO3 is incompatible? *why there is a need t o boil the solution before reaching the methyl orange endpoint? *...
December 22, 2008 by tintin

acids and alkalis
can you tell me me some acids and alkalis that are used in the house acids. vinegar(acetic acid), lemon juice (citric acid), cream of tartar (potassium hydrogen tartrate), vanish (sodium hydrogen sulfate--but I think the newer product has changed the active ingredient). bases...
January 18, 2007 by abigal

pH- part 2
how much .10M Base (in mL) is needed to neutralize 8.00mL of .10M Acid? base- NaOH, acid- HCl, base volume (mL)- ? base- NaOH, acid- HC2H3O2, base volume (mL)- ? VaNa=VbNb Vb= 8ml*.10N/.10N= 8m.
April 14, 2007 by Christine

chemistry steps check
What is the pH of the solution created by combining 11.10 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)? This is exactly like what Dr Bob has shown me on the first problem i put here and yet i get this simple one wrong... Here are my steps: NaOH: 0.0111L x.1 M...
May 2, 2008 by Amy

organic chem
(b) One of your illustrious colleagues continues his/her education and finally obtains employment with a renowned pharmaceutical company as an organic chemist. He or she is asked to synthesize pantothenic acid because the company wants to use it to prepare a synthetic form of ...
April 26, 2011 by adam

Chemistry
A 1.250 g mass of standard aspirin is dissolved in approximately 20 mL of 1 M NaOH. This solution is added to a 250-mL volumetric flask and diluted to the mark with DI water. How many grams per mL of aspirin are in the resulting solution? (Note that a 250-mL volumetric flask ...
January 26, 2014 by Anonymous

chemistry
50.0 mL of a solution of HCl is combined with 100.0 mL of 1.15 M NaOH in a calorimeter. The reaction mixture is initially at 22.4°C and the final temperature after reaction is 31.2°C. What is the molarity of the HCl solution? You may assume that there is an excess of base (so ...
February 28, 2015 by Marcus

chemistry Plz help!
To make NaTcO4, Tc metal is dissolved in nitric acid to make HTcO4, NO2 and H2O. Then the product HTcO4 is treated with NaOH to make NaTcO4. If you begin with 4.5 mg of Tc metal, how much of NaOH (in grams) is required to convert all of the HTcO4 into NaTcO4? I dont even know ...
December 2, 2008 by Jordan

chemistry
hi, i am trying to develop a lab where i find the solubility of Sodium acetate. I was wondering in i was in the right path. We are given these three compounds: Acetic acid aka vinegar baking soda (sodium hydrogen carbonate) 0.100mol/l Naoh(aq) 0.100/l HCL(aq) So we are not ...
June 2, 2008 by chemistrybuddy

chemistry
A definite amount of NH4cl was boiled with 100ml of 0.8N naoh for complete reaction . After the reaction mixture containing excess of naoh was neutralized with 12.5ml of 0.75N NH2so4. Calculate the amount of NH4cl taken. I want you to explain about 100ml x 0.8N = 80 12.5ml x 0...
February 10, 2013 by Fai

chemistry
The following data were collected at the endpoint of a titration performed to find the molarity of an HCl solution: Volume of acid (HCl) used = 14.4 mL; Volume of base (NaOH) used = 22.4 mL; Molarity of standard base (NaOH) = 0.200 M; What is the molarity of the acid solution...
November 29, 2010 by vin

Chemistry: Molarity
4.82 mL of a 0.262 M NaOH solution reacts completly with 4.79 mL of HCl solution according to the balanced chemical reaction shown below: HCl (aq) + NaOH (aq) -> NaCl*aq) + H2O (I) What is the molarity of the HCl solution? 4.82 x (1L/1000 mL) = .00482L 4.79 x (1L/1000 mL...
March 1, 2009 by Bob

chemistry
If 15.0 mL of a 1.5M HCl solution at 22.5 degrees C is mixed with 25.0mL of a 1.5M NaOH solution at 21.5 degrees C that is in a calorimeter, and the final mixed solution temperature ends up at 28.5 degrees C, 1.)what is the balanced equation for this reaction? 2.) what is the ...
April 13, 2014 by Alison

chemistry
If you pass 10.0mL of a 50.0mL solution of [Co(en)2Cl2]Cl that has been reduced with Zn through a cation exchange column, you will obtain a solution that has three H+ ions for every Co3+ ion that was originally present in the sample. These H+ ions are titrated with 0.10-M ...
October 26, 2014 by xx

chemistry desperately
i am completely lost, i confused myself. i need to find the concentration of HC2H3O2 HC2H3O2 + NaOH ==> NaC2H3O2 + HOH NaOH C= 0.3 M v= 0.25 L n= 0.075 moles M= 40.00g/mol m= 3.00 g NaC2H3O2 n= 0.075 moles m= 0.4973 g(ammount of acetic acid in solution) HC2H302 v= 0.020 L M...
December 16, 2008 by diana

Chemistry
Which of the following mixtures will result in the formation of a buffer solution if all solutions are 1.0 M before mixing? i) 100. mL of NH3(aq) and 100. mL of HCl(aq). ii) 100. mL of NH3(aq) and 50. mL of HCl(aq). iii) 100. mL of NH3(aq) and 50. mL NaOH(aq). iv) 100. mL of ...
July 18, 2009 by Paul

Chemistry
We conducted a lab with antacids in class the other day and i'm having trouble doing the calculations. Well we basically took antacid tablets dissolved them in HCl, heated it and then added phenolthalien and then titrated until we saw a pink color. At 41mL we saw the pink and ...
March 15, 2010 by Anonymous

Chemistry
I've been given the Volume of Concentrated NaOh solution (mL) and also the Concentration of Concentrated NaOh solution (M). I also have the volume of stock solution after dilution (mL). The question is asking the approximate concentration of stock solution (M) any help?
October 31, 2008 by Vanessa

Chemistry
Given a 1.00 M solution of NaOH, describe how you would prepare 500 mL of 0.05 M NaOH solution. You have a 500 mL volumetric flask and a graduated cylinder. I have been trying to figure this question out for over an hour now. I cant seem to place the given numbers into any ...
November 20, 2014 by Chloe

chemistry
A home swimming pool is disinfected by the daily addition of 0.50 gal (1 gal = 3.785 L) of a "chlorine" solution–NaOCl in NaOH(aq). To maintain the proper acidity in the pool, the NaOH(aq) in the "chlorine" solution must be neutralized. By experiment it is found that about 220...
October 9, 2012 by joe

Organic Chemistry
I realize this is a general chemistry stoichiometry question, however I can not fully grasp it. I am supposed to calculate the theoretical amount (volume) of 3M sodium hydroxide (NaOH) needed to convert 1.5g of benzoic acid to its salt. I got 0.012 moles of bezoic acid present...
January 20, 2011 by Me

chemistry
Calculate ∆T for the reaction. Assume the initial temperature of both reactants is 25.0◦C. Calculate the volume of the reaction mixture. Calculate the mass of the reaction mixture. Assume the density of the mixture is 1.03 g mL^(-1). Calculate the heat transferred ...
October 22, 2014 by Anonymous

Chemistry
A student titrated 1.852 g of a mixture containing potassium hydrogen phthalate, KHP....? A student titrated 1.852 g of a mixture containing potassium hydrogen phthalate, KHP, with 0.163 M NaOH solution. She recorded an initial buret reading of 0.84 mL and a final buret ...
March 7, 2012 by Cynthia

chemistry help
A 15.00 mL sample of an unknown monoprotic weak acid solution is titrated with 0.35 M NaOH. The initial buret reading is 0.23 mL. The phenolphthalein indicator turns the solution light pink when the buret reads 29.58 mL. B. How many moles of NaOH were delivered? C. How many ...
April 1, 2015 by jk

chem
Consider the reaction that occurs on mixing 50.0 mL of 0.560 MNaHCO3 and 50.0 mL of 0.400 M NaOH at25oC. (a) Write a balanced net ionic equation for thereaction. (b) What is the pH of the resulting solution? (c) How much heat (in joules) is liberated by thereaction? (standard ...
March 29, 2011 by pal

Chemistry
If 100mL of 1mol HCL is mixed with 100 mL of 1mol NaOH, a temp rise of 6.2C occurs. What temp change will be obserbed, if under the same conditions, 10mL of 1mol NaOH is mixed with 10mL 1mol HCL? x Why wouldn't it be the same? One gets 1/10 th of the heat, but has only 1/10th ...
February 1, 2007 by susie

College Chemistry (DrBob222)
A solution of an unknown weak acid, HA, is titrated with 0.100 M NaOH solution. The equivalence point is achieved when 36.12 mL of NaOH have been added. After the equivalence point is reached, 18.06 mL of 0.100 M HCl are added to the solution and the pH at that point is found ...
March 25, 2014 by Anonymous

chemistry
In the lab, 20.0 g of sodium hydroxide is added to a beaker giving it a total mass of 128.4 g. Sulfuric acid is added until all of the sodium hydroxide reacts. After heating, the total mass of the beaker and the dry compound is 142.3 g. Caculate the percent yeild. 2NaOH + ...
June 13, 2007 by jill

chem
I have a titration of 30ml of .360 M H2C6H6O6 Its K1 =6.8E-5 K2 =2.8 E-12 With .280 M NaOH. It is a weak acid being titrated by a strong base Its a two step process with the ice table to find the eqpts. Ineed to list the volumes of NaOH needed for the titration as I go. Been ...
July 10, 2011 by ted

chemistry
qualitative organic analysis lab 1. Why is it important to have clean test tubes before running a test? Before which tests should acetone not be used to clean the test tubes? 2. Why run solubility tests before running the functional group classification tests? 3. Determine ...
October 30, 2014 by Niah

chemistry.
Which solution contains 0,1 mol of sodium hydroxide? A- 1 cm3 of 0,1 mol dm3 NaOH B 10 cm3 of 0,1 mol dm3 NaOH C 100 cm3################### d 100 cm3 ###################
November 5, 2009 by Mark

chemistry
We are determining the molarity of HCl by titration of HCl. What would be the complete equation and the net ionic equation? THanks What are you titrating it with? Won't that make a difference in the equation we write? It's titration of HCl with NaOH. molecular equation: HCl + ...
September 17, 2006 by bria

Chemistry
Tartaric acid has two acidic (ionizable) hydrogens. The acid is often present in wines and precipitates from solution as wine ages. A solution containing an unknown concentration of the acid is titrated with NaOH. It requires 22.62 mL of 0.2000 M NaOH solution of titrate both ...
October 10, 2011 by Destiny

chemistry
the titration of 25.0 mL of a 0.040 M aqueous solution of maleic acid C2H2(COOH)2, with aqueous 0.10 M NaOH solution. For maleic acid, Ka1 = 0.013 and Ka2 = 8.5 x 10-7 How many milliliters of the 0.10 M NaOH solution are needed to completely react all the maleic acid in 25.0 ...
June 30, 2013 by sue

Chemistry
Greetings: I was wondering how to calculate the weight/volume % of vinegar using the formula ---------------w/v Per Cent = g/100 mL or grams per deciliter: WHAT WEIGHT DO I USE NaOH, Acetic ACID? the data include: volume of NaOH needed to neutralize Vingegar : 14.24 mL Volume ...
October 1, 2008 by Matthew

Chemistry
500.0 mL of 0.220 mol/L HCl(aq) was added to a high quality insulated calorimeter containing 500.0mL of 0.200 mol/L NaOH(aq).Both solutions had a density of 1g/mL & a specific heat of 4.184 J/g.K.The calorimeter had a heat capacity of 850 J/C.Temperature of entire system rose ...
March 26, 2012 by Meenaakshi

Chemistry
.01 mols of a weak acid is dissolved in .1 L of water. That solution is then reacted with .01 mols of NaOH. Would the resulting solution be acidic, basic, or neutral? Why? What reaction equations support the explanation? I think the answer is that the resulting solution would ...
February 12, 2014 by Anonymous

Chemistry
0.688g of antacid was treated with 50.00ml of 0.200M HCl. The excess acid required 4.21 mL of 1.200 M NaOH for back-titration. What is the neutralizing power of this antacid expressed as mmol of HCl per gram of antacid? I think the answer should be: (50.00ml HCl)(0.200M HCl)= ...
April 6, 2015 by Michelle

Chemistryyy
a) A standard solution of 0.243 M NaOH was used to determine the concentration of a hydrochloric acid solution. If 46.33 mL of NaOH is needed to neutralize 10.00 mL of the acid, what is the molar concentration of the acid? b) A 0.150 M sodium chloride solution is referred to ...
September 12, 2014 by Xaxus

chimestry
more volume of NaOH means more moles of NaOH (volume * molarity = mole ; molarity=constant) , more moles of NaOH means more grams and mole of HCl and more grams and/or mole and/mass of M2CO3 (note that they are both on the same side of the reaction) now note that if the mass ...
November 8, 2010 by fred

chemistry
19 mL of 0.50 mool/L NaOH which is standardized becomes titrated alongside 24 mL of 0.44 mol/L acetic acid. Determine the pH of the solution Please judge my work: Becasue NaOH and acetic acid react in a 1:1 ratio, initital moles of acetic acid =0.0019 L x 0.44M = 0.000836 mols...
April 9, 2008 by Joseph

Chemistry Help(Calorimetry)
I have a few questions to ask, since I was absent from school and I do not really understand the calorimetry problems. 1) When a 16.9 g sample of NaOH dissolves in 70.0 g of water in a calorimeter, the temperature rises from 22.4*C to 86.6*C. Calculate for Delta H for the ...
April 9, 2010 by Bonn

Chemistry
When 35.0 mL of 1.43 M NaOH at 22.0 degres Celsius is neutralized by 35.0 mL of HCL also at 22.0 degrees Celsius in a coffee-cup calorimeter, the temperature of the final solution rises to 31.29 degrees Celsius. Assume that the specific heat of all solutions i 4.18 J/ g* C, ...
March 19, 2010 by Google

Chemistry
- What effect would be on the normality of unknown acid? Explain why. (standarized NaOH in the burette) a) if a wet burette is used for NaOH (that has a known normality) b) if a wet conical flask is used for the titration against the acid c) if an air bubble is out from the ...
May 16, 2014 by Peter M.Shaker

Chemistry
Thanks for your help; I am still have a few problems, could you check my work: Given: Volume of vinegar analyzed-5mL Con'c of NaOH-0.09890M Avg. Volume of NaOH from titration-43.75mL Density CH3COOH: 1.049g/mL Calculations: 1.Moles of NaOH required to reach equivalence point= ...
January 31, 2011 by Adam

chemistry
Can someone give me some directions as to how to reach the answer for this problem: A 0.608g sample of fertilizer contained nitrogen as ammonium sulfate, (NH4)2 SO4(s)+2NaOH(aq)-->Na2SO4(aq)+ 2H2O(l)+2NH3(g) The ammonia was collected in 46.3 mL of 0.213 M HCL (hydrochloric ...
June 11, 2009 by Chemically Confused

Chem 30
1) Suppose the mass of the NaOH used in a reaction was doubled. What would you expect to happen to the heat given off by the reaction? Explain your answer. 2)Again, suppose the mass of the NaOH used in a reaction was doubled. What would you expect to happen to the heat given ...
January 3, 2012 by Brett

AP CHEMISTRY
I really need this please!!!!!!! : write the equilibrium-constant expression and calculate the value of the equilibrium constant for each of the following reactions at 298 K. (a) NaHCO3(s)<--> NaOH(s) + CO2(g) Answer: Keq = PCO2 (b)Value of the Equilibrium Constant: ...
March 19, 2012 by DAN

AP CHEMISTRY
I really need this please!!!!!!! : write the equilibrium-constant expression and calculate the value of the equilibrium constant for each of the following reactions at 298 K. (a) NaHCO3(s)<--> NaOH(s) + CO2(g) Answer: Keq = PCO2 (b)Value of the Equilibrium Constant: ...
March 19, 2012 by DAN

Chemistry, reactions w/ water
Write the equation for the reaction of each of the following with water. a) HCl b) CH3COOH c) NaOH d) NH3 Are these correct? a. HCl (aq) + H2O (l) --> H3O+ (aq) + Cl- (aq) b. CH3COOH (aq) + H2O (l) --> CH3COO- (aq) + H3O+ (aq) c. NaOH (aq) + H2O (l) --> Na+ + OH- + ...
May 6, 2008 by Marissa

Chemistry
4. A 5.309 g antacid tablet, with CaCO3 as the active ingredient, was mixed was 30.0 mL of 0.831 M HCl. It took 15.3 mL of 0.7034 M NaOH to neutralize the excess acid. a) Calculate the volume of HCl neutralized by the NaOH. b) Calculate the amount of HCl (in mL) neutralized by...
April 2, 2013 by Josh

Chemistry
Determine the moles of ammonia in the following cobalt ammine complex: A sample of .1500 g of the cobalt ammine complex is places in a flask and 25.00mL of .200M HCL is added. a few drops of bromocresol green is added and the titration with .100M to NaOH required 16.42mL. I ...
March 16, 2010 by james

Chemistry
When 3g of sodium hydroxide (NaOH) was dissolved in 150g of water a value of 10.5 degrees C was obtained for delta T. Calculate the heat (calories) produced by the solution of 3 g of NaOH Calculate the number of calories that would be produced if one mole of sodium hydroxide ...
November 2, 2006 by Talina

Aqueous Stoichiometry
Can someone give me some directions as to how to reach the answer for this problem: A 0.608g sample of fertilizer contained nitrogen as ammonium sulfate, (NH4)2 SO4(s)+2NaOH(aq)-->Na2SO4(aq)+ 2H2O(l)+2NH3(g) The ammonia was collected in 46.3 mL of 0.213 M HCL (hydrochloric ...
June 11, 2009 by Chemically Confused

chemistry
We titrated Sprite with 0.1051 M standard NaOH. I've ploted three different titrations and am supposed to use the titration curve to identify the acid. I assume the acid is Citric since it's Sprite, but the lab manual also says "to recall that two K values must be far enough ...
March 21, 2011 by redgy

Chemistry.. help plz
3. How much 0.10 M Base (in mL) is required to neutralize 8.00 mL of the 0.10 M acid? Base Acid Base Volume (mL) NaOH HCl ____________ NaOH HC2H3O2 _____________ 4. How would the volume of base change from problem three if the 8.00 mL of 0.10 M Acid was first diluted with 100...
May 1, 2008 by Amy

Chemistry
I really don't know how to approach this problem and I really need help. Using the average molarity of your initial acetic acid solutions, the initial volumes, and the volume of NaOH added to reach the equivalence point, calculate the [C2H3O2-] concentration at the equivalence...
May 6, 2010 by Megan

chemistry
Why does the equivalence point occur at different pH values for the four titration studied? the four titrations were: 1. HCL with NaOH 2.HC2H3O2 with NaOH 3. HCl with NH4OH 4. HC2H3O2 with NHOH Okay so equivalence point is when the number of moles of acids and bases are equal...
May 9, 2008 by Amy

Chemistry
An antacid tablet weighing 1.462 grams was dissolbed in 25mL of 0.8M HCl and diluted with water. The excess HCl was titrated with 3.5 mL of 1.019M NaOH solution. 1. Calculate the number of millimoles added to the tablet 2. Calculate the number of millimoles of NaOH required to...
July 1, 2010 by Daria

Chemistry
An antacid tablet weighing 1.462 grams was dissolbed in 25mL of 0.8M HCl and diluted with water. The excess HCl was titrated with 3.5 mL of 1.019M NaOH solution. 1. Calculate the number of millimoles added to the tablet 2. Calculate the number of millimoles of NaOH required ...
October 4, 2010 by Jennifer

Chemistry
1) Write a balanced chemical equation for the reaction between Cu(NO3)2 * 3 H2O and NaOH. Underline the formula for the precipitate produced by this reaction. (The water of hydration in Cu(NO3)2 * 3 H2O appears as liquid water on the right side of the equation) 1. Cu(NO3)2....
May 17, 2010 by Sarah

chemistry
The following reaction is at equilibrium at a pressure of 1 atm, in a closed container. NaOH(s) + CO2(g) NaHCO3(s); ΔH°rxn < 0 Which, if any, of the following actions will decrease the concentration of CO2 gas present at equilibrium? A. lowering the temperature B. ...
April 23, 2010 by bme1

chemistry-
How do I construct an ICE table for this question. CH3COOH + NaOH --> CH3COONa + H2O Fill in the equilibrium line of the table. [Think about the initial pH and think about the pH at the end point of the titration. Initial pH 2.72 When the solution turned pink pH was 8.49 I ...
May 9, 2007 by Jason

Chemistry
1. As I understand it--As an acid is added to neutral water the (OH-) will...decrease?? Is this right? 2. If you made up a solution of NaOH by adding 0.010 mole of solid NaOH to 1.0 L of distilled water, what would be the concentration of the OH-?...I think this would be a pOH...
May 15, 2012 by April

Organic Chemistry
separation and purification scheme how would i begin this? we have a mixture of the following:50% benzoic acid, 40% benzoin, 10% dibromobenzene they give us 1M NaOH, 6M NaOH, 1M HCl, 6M HCl, 1M NaHCO3, saturated sodium chloride, diethyl ether, 95% ethanol, methanol, isopropyl ...
October 1, 2010 by Jen

AP Chemistry
A mixture of 20.0 grams of CaO and BaO is placed in a 12.5 L vessel at 200oC with excess CO2 . The mixture is allowed to react to completion forming CaCO¬3 and BaCO3 .The pressure in the container after reaction is 220 torr. The solid carbonates are neutralized by adding 650.0...
January 2, 2015 by Jim

chemistry
How much 0.10 M Base (in mL) is required to neutralize 8.00 mL of the 0.10 M acid? Base Acid Base Volume (mL) NaOH HCl ___________ NaOH HC2H3O2 ___________ How would the volume of base change from problem above if the 8.00 mL of 0.10 M Acid was first diluted with 100 mL of ...
May 1, 2008 by Amy

chemistry
How much 0.10 M Base (in mL) is required to neutralize 8.00 mL of the 0.10 M acid? Base Acid Base Volume (ml) NaOH HCl ___________ NaOH HC2H3O2 ___________ How would the volume of base change from the problem above if the 8.00 mL of 0.10 M Acid was first diluted with 100 mL of...
May 1, 2008 by Amy

Chemistry [sumone help me please :(]
0.250g of phthalic acid is dissolved in 40.00cm^3 of 0.100 mol dm^-3 NaOH. It requires 11.80 cubic centimeters of 0.100 mol\dm^-3 HCL fo neutralisation( to phenolphthalein) The mole ratio in which phthalic acid reacts with sodium hydroxide ihn 1:2 (a) Calculate the moles of ...
September 21, 2011 by Petty

CHEM 136
A sample of 25.00 mL of 0.100 M HNO2(in a flask) is titrated with 0.150 M of NaOH solution at 25 degrees. 1) calculate the volume(Ve) of the NaOH solution needed to completely neutralize the acid in the flask. 2)calculate the pH for (a)the initial acid solution in the flask (b...
November 23, 2010 by Jefferson

Chemistry
Q1: You wish to prepare a buffer solution with pH = 11.10. What volume of 6.0 M HCl would you add to 500 mL of 0.10 M (C2H5)2NH to prepare the buffer? You may assume that the solution’s volume remains constant. Q2: What is the resulting pH when 20 mL of 0.20 M NaOH is added to...
February 24, 2013 by David

Chemistry
Q1: You wish to prepare a buffer solution with pH = 11.10. What volume of 6.0 M HCl would you add to 500 mL of 0.10 M (C2H5)2NH to prepare the buffer? You may assume that the solution’s volume remains constant. Q2: What is the resulting pH when 20 mL of 0.20 M NaOH is added to...
February 24, 2013 by Anonymous

science
how would you make 500.0mL of a 0.200M NaOH solution from a 15.0 M stock NaOH solution?? I assume that you want the volumes rather than the mechanics of carrying it out? a) How many moles do you need in the 500 ml to have 0.200 M? b) What volume of 15.0 M would contain the ...
April 5, 2007 by Mel

DrBob222 : need help with the problem
An unknown compound, X, is though to have a carboxyl group with a pKa of 2.0 and another ionizable group with a pKa between 5 and 8. When 75 mL of 0.1M NaOH is added to 100 mL of a 0.1M solution of X at pH 2.0, the pH increases to 6.72. Calculate the pKa of the second ...
September 11, 2012 by ron

Chemistry
When 2.25 g of sodium hydroxide (NaOH) was dissolved in 150.00 g of water a value of 11.00oC was obtained for ΔT. 1. Calculate the molarity of the sodium hydroxide solution. 2. Calculate the value (calories) for the heat of solution of 2.25 g of NaOH. 3. Calculate the ...
October 20, 2014 by Kales

chemistry
PLEASE NOTE: Titration requires several steps in order to obtain exact results. The procedures described in this lab assume that you have already done the TITRATION TUTORIAL and are familiar with the technique. 1. Prepare the NaOH solution by dissolving approximately 4g of ...
April 15, 2011 by Zach

Analytical chemistry
A dilute perchloric acid solution was standardized by dissolving 0.2445 g of primary standard sodium carbonate in 50 mL of the acid, boiling to eliminate CO2, and back-titrating with 4.13mL of dilute NaOH. In a seperate titration a 25mL portion of the acid required 26.88 mL of...
August 1, 2013 by Gloria

College Chemistry
Given 20 mL NaOH; 0.1 M, add 0.05 M HCl, 10 mL at a time. What is the pH initially of NaOH? What is the pH after adding 10 mL 0.05 M HCl? What is the pH after adding 20 mL 0.05 M HCl? What is the pH after adding 30 mL 0.05 M HCl? What is the pH after adding 40 mL 0.05 M HCl? ...
July 7, 2010 by Erika

Chemistry(Please help, thank you!)
For a chemistry lab the experiment was to carry out an acid-base titration to determine the exact concentration of a sodium hydroxide solution. Two trials were completed and the data collected was: mass of weighing paper, mass of weighing paper + KHP, mass of KHP, initial ...
October 24, 2011 by Hannah

AP CHEMISTRY HELP
a) A student fails to wash the weighing paper when transferring the KHP sample into the beaker. What effect does this error have on the calculated molarity of the NAOH solution? Mathematically justify your answer. b) A student failed to notice an air bubble trapped in the tip ...
December 20, 2012 by Amber

chemistry
I need some help with calculating percent yield and percent purity of aspirin. Here's my data (questions follow): SYNTHESIS Mass of salicylic acid.., 2.0 g Volume of acetic anhydride.., 5 mL Mass of watch glass.., 22.10 g Mass of aspirin and watch glass.., 28.01 g Mass of ...
March 24, 2007 by Jim

Chemistry II
The enthalpy of neutralizatino for the reaction of a strong acid with a strong base is -56 kJ/mol of water produced. How much energy will be released when 230.0 mL of 0.400 M HCl is mixedwith 150.5 mL of 0.500 M NaOH? How much water is produced in the reaction? How do I figure...
May 20, 2007 by Jayd

Chemistry
Question: A volume of 26.00ml of 4.30 M. HCL is mixed with 33.70 ml of 10.80 M H3PO4 s mixture is diluted to 1.00 liter with distilled water. A 50.00 ml portion of this diluted mixture is than titrated with .2200 M. NaOH. a) compute the concentration of phosphoric acid after ...
April 19, 2009 by Eliz

CHEMISTRY PLEASE HELP
Using the data collected for part c on your data sheet and assuming the density of the vinegar is 1.00g/mL, 1) calculate the molar concentration of acetic acid (CH3COOH) in the vinegar sample using the average volume of NaOH. 2) calculate the mass percent of acetic acid in the...
October 24, 2011 by Josh

Chemistry
HCl(aq) +NaOH(aq) ---> NaCl +H2O In a coffee cup calorimeter 50 ml of 2.00M HCl was combined with 50ml of 2.05M NaOH. a) What is the enthalpy change for the reaction? b) What is the molar enthalpy for the reaction? Given: Change in T= 14 degrees celsius heat capacity of the...
October 8, 2013 by Kuu

CheMistry
A stock solution was prepared by dissolving exactly 0.4000 g of pure ASA (180.16 g/mol) in 10.00 mL of NaOH and heating the solution to a gentle boil. After cooling to room temperature, the solution was poured into a 250-mL volumetric flask and diluted to the mark with DI ...
April 18, 2010 by ChEm

Chemistry
Using the data collected for part c on your data sheet and assuming the density of the vinegar is 1.00g/mL, 1) calculate the molar concentration of acetic acid (CH3COOH) in the vinegar sample using the average volume of NaOH. 2) calculate the mass percent of acetic acid in the...
October 24, 2011 by Josh

chemistry
Im stuck on these few questions that seems to be getting me no where : -Determine the number of mmoles of HCl that did not react with the anatacid. c HCl = 0.1812 c NaOH = 0.1511 volume of HCl added : 75 volume of NaOH added: 29.23,19.58,33.3 - mmoles of HCl neutralized by the...
October 8, 2013 by karen

chemistry
Im stuck on these few questions that seems to be getting me no where : c HCl = 0.1812 c NaOH = 0.1511 volume of HCl added : 75 volume of NaOH added: 29.23,19.58,33.3 -Determine the number of mmoles of HCl that did not react with the anatacid. - mmoles of HCl neutralized by the...
October 8, 2013 by kathy

science( chem)
When 100.0ml of a weak acid was titrated with 0.09381M NaOH, 27.63ml were required to reach the equivalence point. The pH at the equivalence point was 10.99. What was the pH when only 19.47ml of NaOH had been added ? I'll just post my work and I need someone to check and see ...
July 22, 2007 by christina

chemistry
Which of the following when added to 100.0mL of a 0.100M soln of NH4Cl would produce a buffer soln? a.100.0mL of 0.100 M HCl soln b. 100.0mL of 0.050M NaOH soln c. 100.0mL of 0.100M NaOH soln d. 100.0mL of 0.050M NH4No3 soln e.none of the above
July 27, 2010 by Jin

chemistry (continued)
i kinda understand waht you're saying. to be a bit more clear this is from a lab, and here are the volumes we retrieved: Volume of Concentrated NaOH soultion (mL) = 9.00 mL Concentration of Concentrated NaOH soultuon (M) = 6.00 M Volume of Stock Solution after Dilution (mL) = ...
October 31, 2008 by Vanessa

Chemistry
I wanted to calculate the normality of the acid and base solutions for a lab. But I'm extremely confused. I know normality is number of equivalents divided by volume in liters. But are we suppose to be given the number of equivalents of HCl and NaOH? Or are we suppose to ...
March 3, 2012 by Priscilla

AP Chemistry
Write the balanced molecular, complete ionic, and net ionic equations for each of the following acid-base reactions. (Type your answer using the format [NH4]+ for NH4+ and [Ni(CN)4]2- for Ni(CN)42-. Use the lowest possible coefficients.) (a) HClO4(aq) + Mg(OH)2(s) molecular ...
September 24, 2011 by Rahul

Ap chemistry
Suppose NaOH is added to the following system when it is at equilibrium. NH3 (aq) + H2O (l) = NH4 (aq) + OH (aq) a) in which direction will the reaction shift after the NaOH is added? b) will this stress increase or decrease the value of the reaction quotient, Q? C) will the ...
March 5, 2015 by Ivey

chem help w/ Lab
Weight of the mustard package Sample: 3.02 (g) Weight of the mustard package Solution: 33.3 (g) Trial #1 Trial #2 Trial #3 Weight of Mustard Package Solution Delivered (g) : 1.09 .948 .909 Weight of NaOH Solution Delivered (g) : .354 .304 .269 Concentration of NaOH : 7.48e-3 (...
October 17, 2012 by Den

Chemistry
The pH of a weak monoprotic acid, HA, is 4.55. It took 39.22 ml of 0.2334 M NaOH to titrate 25.00 ml of the acid. a. Write an equation for the above reaction. b. Calculate the molarity of the weak acid c. Write the equilibrium equation. Construct a table showing initial ...
April 9, 2011 by Cassie

Chemistry
A chemical plant uses electrical energy to decompose aqueous solutions of NaCl to give Cl2,H2, and NaOH: 2NaCl(aq)+2H2O(l)-->2NaOH(aq)+H2(g)+Cl2(g) If the plant produces 1.1×10^6 kg (1100 metric tons) of daily, estimate the quantities of H2 produced. If the plant produces 1...
September 27, 2011 by Brennan

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