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April 23, 2014

Search: Na2S2O3

Number of results: 141

Chemistry
You want to prepare 750 mL of a 0.4M Na2S2O3 solution. You want how many mols? That's M x L = 0.40 M x 0.750 L = 0.30 mols. mols Na2S2O3 = grams Na2S2O3/molar mass g = mols x molar mass = 0.3 x molar mass Na2S2O3. Weigh out that many grams Na2S2O3, place into a 750 mL ...
Tuesday, September 25, 2012 at 2:50pm by DrBob222

college chem
how many milliliters of 0.200 M Na2S2O3 are needed to provide 0.0388 mol Na2S2O3?
Tuesday, June 2, 2009 at 7:06pm by kelly

Chemistry*
The following equation is given: S2O3 -2 + 2H +1 ---> S + SO2 + H2O [HCl] = 2 mol/L [Na2S2O3]= 0.3 mol/L what is the concentration (mol/L) of H+ if you were to add: a) 20 mL of HCL with 5 mL Na2S2O3 & with 5 mL H2O b) 15 mL of HCl with 5 mL Na2S2O3 & 10 mL H2O c) 7.50 mL of...
Thursday, November 4, 2010 at 5:38pm by Stephanies

chemistry
Calculate the mass of solid Na2S2O3•5H2O required to prepare 300. mL of 0.0200 M Na2S2O3
Monday, October 1, 2012 at 6:20pm by Nicolai

Chemistry
I think you have several problems before you start. First, I don't think the M of the KIO3 can be a number such as about 45 M. That's just too large. Second, have you shown all of your reactions? Usually one doesn't titrate KIO3 with Na2S2O3. Are you adding KI to the solution...
Sunday, March 6, 2011 at 9:06pm by DrBob222

chemistry
First, most sodium salts are soluble in aqueous solution. Second, you don't say if you are using Na2S2O3 or Na2S2O3.5H2O NOR what you mean by "large amount."
Saturday, April 3, 2010 at 7:02pm by DrBob222

Analytical Chemistry
Unfortunately, my KIO3 was given to me in mL from my professor so i have no clue what the grams of KIO3. I tried to figure out the moles of Na2S2O3 solution but looking over it i believe that 0.28 M is incorrect. The info I have is: 2.6g of Na2S2O3 was added to roughly 1 mL of...
Monday, October 11, 2010 at 10:12pm by Max

Chemistry-iodometric titration
mL Na2S2O3 x N Na2S2O3 = # milliequivalents. Then #milliequivalents x milliequivalent weight = grams.
Wednesday, August 4, 2010 at 7:39pm by DrBob222

AP chem
How do you propose a mechanism for this reaction: 18H(+) + 4S2O3(2-)-->SO3(2-) + 7S + 9H2O where the rate law: rate=k[Na2S2O3] with first order respect to Na2S2O3...
Sunday, February 18, 2007 at 2:53am by anonymous

Chemistry
For chem we did a kinetics lab based on the rate of reaction of peroxydisulfate ion with iodide ion. I'm supposed to find the amount of S2O3 ^2- consumed for every trial (in moles) If someone could just explain how to do that with the information I currently have, that would ...
Thursday, February 13, 2014 at 12:10am by Anonymous

chemistry
The problem asks for mass Na2S2O3.5H2O. You calculated mass Na2S2O3. Add the 5 mols H2O to find the mass of the hydrated salt.
Monday, October 1, 2012 at 6:20pm by DrBob222

Chemistry
What is the full net ionic equation for each reaction? do they form a precipitate or have a color change? CuSO4+AgNO3 CuSO4+BaCl2 CuSO4+Cu(NO3)2 CuSO4+Pb(NO3)2 CuSO4+KI CuSO4+Na2S2O3 AgNO3+BaCl2 AgNO3+Cu(NO3)2 AgNO3+Pb(NO3)2 AgNO3+KI AgNO3+Na2S2O3 BaCl2+Cu(NO3)2 BaCl2+Pb(NO3)2...
Tuesday, May 27, 2008 at 6:49pm by Joe

Chemistry
What is the full net ionic equation for each reaction? do they form a precipitate or have a color change? CuSO4+AgNO3 CuSO4+BaCl2 CuSO4+Cu(NO3)2 CuSO4+Pb(NO3)2 CuSO4+KI CuSO4+Na2S2O3 AgNO3+BaCl2 AgNO3+Cu(NO3)2 AgNO3+Pb(NO3)2 AgNO3+KI AgNO3+Na2S2O3 BaCl2+Cu(NO3)2 BaCl2+Pb(NO3)2...
Tuesday, May 27, 2008 at 6:50pm by Joe

chemistry
Sodium thiosulfate, Na2S2O3, is used as a fixer in photographic film developing. The amount of Na2S2O3 in a solution can be determined by a titration with iodine, I2, according to the equation: 2Na2S2O3(aq) + I2(aq) --> Na2S4O6 +2NaI(aq). Calculate the concentration of the ...
Sunday, March 2, 2014 at 10:53pm by Muhammad

Chemistry
2 ml of 1M HCl 0 ml of H2O 3ml of .3M Na2S2O3 How do I find the initial and final concentrations of both HCl and Na2S2O3?
Monday, January 7, 2013 at 10:10pm by Nicole

Analytical Chemistry
I am trying to find moles of IO3 from Cu(IO3)2 10 ml and standardized sodium thiosulfate (Na2S2O3.5H20) .28 M. My calc is: 0.28 Moles Na2S2O3.5H20 * (2 moles of S2O3/1 mole Na2S2O3.5H20)* (2 moles of (IO3)/1 mole Cu(IO3)2= (1.12/.01 L) but that is why to high for (M) what am I...
Monday, October 11, 2010 at 10:12pm by Max

Chemesitry!
Sodium thiosulfate, Na2S2O3, is used as a fixer in photographic film developing. The amount of Na2S2O3 in a solution can be determined by a titration with iodine, I2, according to the equation: 2Na2S2O3(aq) + I2(aq) --> Na2S4O6 +2NaI(aq). Calculate the concentration of the ...
Friday, October 5, 2012 at 4:02pm by Anonymous

chemistry
compute volume and/ or weights of reagents to make the following solution. Desired concentration: 40% NaOH + 4% Na2S2O3 Desired quantity: 1500 mL Given: 90% w/w NaOH, pure Na2S2O3 I'm not sure how to do this so any help would be great. Thanks!
Sunday, September 16, 2007 at 3:41pm by Alan

Chemistry
compute volume and/ or weights of reagents to make the following solution. Desired concentration: 40% NaOH + 4% Na2S2O3 Desired quantity: 1500 mL Given: 90% w/w NaOH, pure Na2S2O3 I'm not sure how to do this so any help would be great. Thanks!
Monday, September 17, 2007 at 8:33pm by Alan

Chemistry
Can someone please help me complete these calculations for my lab; I am having some trouble. A. Standardization of Na2S2O3 -Mass of KIO3 in 100mL = 0.09600g -Calculate Molarity of KIO3= ? Please check: 0.09600g/(214.0g/mol)=4.486x 10^-4 mol -4.486 mol/0.1L= 44.86 M B. ...
Sunday, March 6, 2011 at 9:06pm by Bryant

Analytical Chemistry
Frankly, it makes (almost) no difference how much KI you took, as long as it is enough to react with the KIO3. You don't list a mass KIO3 but I suspect you weighed KIO3 as a primary standard. Then you added the KI to generate I2, then titrated the I2 with the thiosulfate. ...
Monday, October 11, 2010 at 10:12pm by DrBob222

chemistry,
in analyzing household bleach. I have a flask that contains 10.00 mL diluted bleach + 0.4g KI + 20 mL distilled water and 20 drops of 2M HCl. To that I titrated 30.60 mL Na2S2O3 and I need to calculate the number of moles of NaOCl reacted. This is what I was thinking.. ...
Tuesday, April 10, 2007 at 4:49pm by amy

Chemistry
I'm sure the primary reason is that is the way CuSO4 and Na2S2O3 come. I'm also sure that if the anhydrous material is placed in water they will pick up water of hydration. I know for a fact that CuSO4 will and I'm relatively sure Na2S2O3 will do the same.
Saturday, March 13, 2010 at 4:54pm by DrBob222

Chemistry
I2 + 2Na2S2O3 ==> Na2S4O6 + 2NaI mols Na2S2O3 = M x L = ? mols I2 = 1/2 mol Na2S2O3 (from the coefficients in the balanced equation). g I2 = mols I2 x molar mass I2 = ?
Monday, November 19, 2012 at 2:12am by DrBob222

Repost-Chemistry -please help
No, the molarity of the Na2S2O3 isn't needed since the mg/mL (titre) is given. mL Na2S2O3 x mg/mL peroxide x 20 gives the mg peroxide directly.
Tuesday, August 3, 2010 at 8:58pm by DrBob222

Chemistry
Copper(I) Iodide is synthesised by the equation: 2CuSO4.5H2O + 2KI + 2Na2S2O3.5H2O --> 2CuI + K2SO4 + Na2SO4 + Na2S4O6 + 10H2O Would it make a difference if anhydrous CuSO4 and Na2S2O3 are used instead? Why hydrous CuSO4 and Na2S2O3 are used instead?
Saturday, March 13, 2010 at 4:54pm by Alan

Analytical Chemistry
I know I have to find the (M) of the Na2S2O3 in the standard, then find the (M) of IO3- to find the Ksp but Im not finding (M)Na2S2O3 and I have no clue how to find (M) of IO3-
Monday, October 11, 2010 at 10:12pm by Max

chemistry
A drop of starch is added to a mixture of 97.30 ml of 0.1096 M I2 and 97.20 ml of 0.1098 M Na2S2O3. I've already calculated the moles of I2 to be 10.66408 moles and the moles of Na2S2O3 to be 10.67256. Will the solution be blue even if their moles aren't the same?
Thursday, February 5, 2009 at 6:38pm by jean

Chemistry
I had to perform an experiment for rate of reaction. The point of the experiment was to show how changes in reactant concentration, temperature, and catalyst presence can affect the rate of a reaction. The reaction that we studied was H2O2 + 2I^- + 2H^+ -> I2 + 2H2O We had ...
Saturday, February 25, 2012 at 3:30pm by Hannah

Chemistry
I had to perform an experiment for rate of reaction. I have to calculate the concentration of Na2S2O3 in the reaction solutions based on the volume used in each reaction flask and the total volume calculated. There were five flasks used and for all 5 of them 2.50mL of Na2S2O3 ...
Friday, February 24, 2012 at 8:31pm by Hannah

chemistry
Volume of Na2S2O3(aq) required? final burette reading trial1= 45.00 trial2= 44.27 trial3= 45.28 initial burette reading trial1= 0.52 trial2= 1.22 trial3= 2.33 volume of Na2S2O3 used in each trial? average of the two volumes agreeing within 0.10mL? can anyone help me with this ...
Wednesday, November 16, 2011 at 7:19pm by Yul

Science- Chemistry
How do I figure these out? A solution of sodium thiosulfate, Na2S2O3, is 0.1365 M. 29.28 mL of this solution reacts with 39.79 mL of I2 solution. What is the molarity of the I2 solution? 2(Na2S2O3) + I2↔Na2S4O6 + 2(NaI) 16.77 mL of the I2 solution from above is required...
Thursday, November 8, 2012 at 1:48am by Whitney

Chemistry
Im sorry. The point of the experiment was to show how changes in reactant concentration, temperature, and catalyst presence can affect the rate of a reaction. The reaction that we studied was H2O2 + 2I^- + 2H^+ -> I2 + 2H2O We had to set up 6 flasks each with and certain ...
Friday, February 24, 2012 at 8:31pm by Hannah

Chemistry
Na2S2O3 + BaCl2
Tuesday, May 27, 2008 at 6:49pm by Anonymous

Chemistry
Na2S2O3 + AgNO3
Tuesday, May 27, 2008 at 6:50pm by Anonymous

Chemistry
Hi, I'm really having trouble this this chemistry problem. I have the answers; however I don't have extensive knowledge about titrations and I'm struggling with working it out. If anyone could suggest how to work this out (or even where to start) that would be great. Thanks! ...
Sunday, August 26, 2007 at 7:58pm by Stein

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

Chemistry: HELP! PLEASE
a) Addition of Na2S2O3 to I2+I-->I3 in an aqueous layer will turn the solution clear and colourless. Write an equation explaining this observed colour. b) Addition of Na2S2O3 to I2+I-->I3 in an varsol layer will turn the solution pink. Write and equation explaining this ...
Sunday, March 2, 2014 at 11:28am by Natasha

chemistry
How many grams of Na2CO3 are required to Na2S2O3
Monday, April 4, 2011 at 12:14am by Rickia

chemistry
How many grams of Na2CO3 are required to Na2S2O3
Monday, April 4, 2011 at 12:17am by Rickia

phisical sience
Try the some of the following links for information: http://search.yahoo.com/search?fr=mcafee&p=what+reaction+do+you+get+when+adding+3+tespoons+of+Na2S2O3+to+50+ml+of+boiling+water+ Sra
Wednesday, May 18, 2011 at 9:50am by SraJMcGin

Chemistry
How to prepare a 750mL stock solution with a 0.40 M Na2S2O3.
Tuesday, September 25, 2012 at 2:50pm by GoodinChem619

Chemistry
These are what i used. 0.0375M sodium thiosulphate , 2.5% KI .47.2 ml copper sulphate solution. the average volume of Na2S2O3 is 19.25 cm, i have already calculated the number of moles of thiosulphate which is 7.218 * 10-4 moles of Na2S2O3 and also the number of moles of I2 ...
Sunday, February 26, 2012 at 4:06pm by Sarah

chemistry
A stock solution's hypochlorite activity was determined as follows: . - 2.00g of liquid sodium hypochlorite (NaOCl) was weighed into a flask and diluted with 50mL deionized water.10mL of 10% sulfuric acid and 10mL of 10% potasssium iodide were added, followed by titration with...
Wednesday, August 4, 2010 at 8:17pm by angela

Chemistry
Hi DrBob, Sorry about that, I wasn't very clear! Can someone please help me complete these calculations for my lab; I am having some trouble. A. Standardization of Na2S2O3 -Mass of KIO3 in 100mL = 0.09600g -Calculate Molarity of KIO3= ? Please check: 0.09600g/(214.0g/mol)=4....
Sunday, March 6, 2011 at 11:42pm by Bryant

college chemistry
How do I name the following compounds; K2S2O8, S2O8{-2}, Na2S2O3 and S2O3{-2}
Wednesday, February 25, 2009 at 9:09am by Steven

chemistry
I am using Na2S2O3.5H2O. By large amount i mean about 15 grams
Saturday, April 3, 2010 at 7:02pm by alex

Chemistry
hi i was just wondering what the solution would be to: AgNO3 + Na2S2O3 + sunlight (light enegy) ?
Tuesday, May 27, 2008 at 6:50pm by T

phisical sience
what reaction do you get when adding 3 tespoons of Na2S2O3 to 50 ml of boiling water
Wednesday, May 18, 2011 at 9:50am by Siphesihle

Analytical chemistry
What is the reaction & calculation when KIO3 mixed with KI, HCl by titration with Na2S2O3?
Friday, July 8, 2011 at 5:42pm by Selim

Chemistry
Are the following chemicals light sensitive? 1) Potassium Iodide (KI) 2) Sodium thiosulphate (Na2S2O3)
Saturday, January 8, 2011 at 9:52pm by candy

Chemistry Lab
So I did a kinetics lab on the rate of reaction of peroxydisulfate ion with iodide ion. Part 1 was the effect of concentration. One of the questions asked is to calculate the amount of thiosulfate consumed in moles. My results for trial 1 were (Times taken for consumption of 1...
Sunday, February 2, 2014 at 9:25pm by Anonymous

Analytical Chemistry
Now that I know you are trying to calculate Ksp for Cu(IO3)2, what is the 0.28 M? Is that the molarity of the Na2S2O3 solution?
Monday, October 11, 2010 at 10:12pm by DrBob222

Chemistry
Calculate the molar solubility of barium thiosulfate in 0.0045 M Na2S2O3(aq). (Hint: Check any simplifying assumptions that you make.)
Monday, April 19, 2010 at 3:07pm by Chemistry Confused

Analytical chemistry
The titration is: 2 Na2S2O3 + I2 = Na2S4O6 + 2 NaI moles NaOCl in 20mL aloquat = moles I2 = (1/2)moles Na2S2O3 = 0.345 L * 0.0409 M / 2 moles NaOCl in original (25mL) sample = 0.0345 * 0.0409 * (500/20) mol / 2 mass NaOCl in original (25mL) sample = 74.4424 g/mol * 0.0345 L * ...
Tuesday, July 30, 2013 at 8:55am by Graham

Chemistry - please help
1. You have the wrong formula for sodium thiosulfate. It is Na2S2O3 Try again 2. How about H2S + 2 KOH -> K2S + 2H2O ?
Thursday, December 6, 2007 at 11:58pm by drwls

Chemistry
When aqueous CuSO4 is added to aqueous Na2S2O3, why is there no reaction?
Sunday, September 25, 2011 at 6:33pm by Hannah

Science
Na2S2O3*5(H2O)is hydrated sodium thiosulfate, also known as "hypo". It is a photographic darkroom chemical You need to be more careful which letters in the formula are capitalized.
Tuesday, August 11, 2009 at 3:11am by drwls

Science
What is the scentific formula for Sodium Thiosulphate? What is the mass of a 30 N rock in the school yard? Sodium thiosulfate is Na2S2O3.
Tuesday, October 10, 2006 at 8:04pm by Gina

chemistry
In a measurment 0.1M Kmno4 is used.determine the volume of solution required to react with 0.158M Na2s2o3 required?
Thursday, March 14, 2013 at 1:17pm by Abhishek Bhargav

chemistry
How many grams of I2 are present in a solution if 33.75mL of 0.140M Na2S2O3 solution is needed to titrate the I2solution?
Monday, November 18, 2013 at 11:16pm by Ellen

Science
Sorry, my apologies. After adding Na2S2O3, the Varsol layer became colorless and there was no change in the Aqueous layer.
Sunday, March 9, 2014 at 5:21pm by Karan

Chemisty
For clarity, just assign some number to the volume of a drop. Actually, a drop is between 0.03 and 0.05 mL (depending upon the size of the opening AND on the material that the buret/pipet/dropper is made). BUT, let's just make things simple by saying a drop is 1 mL. We know ...
Wednesday, January 7, 2009 at 10:39pm by DrBob222

chemistry
calculate the numbers of moles of sodium thiosulfate (Na2S2O3) and hence the moles of S2O3^2- ions present in the volume of 43mL can someone plz help me?
Wednesday, November 16, 2011 at 10:56pm by Yul

chemistry
calculate the numbers of moles of sodium thiosulfate (Na2S2O3) and hence the moles of S2O3^2- ions present in the volume of 43mL someone plz help
Wednesday, November 16, 2011 at 10:58pm by myu

Chemistry(Urgent, please help)
All I have is the concentration of S2O3^-2 which is 3.33e^-3M. How would I find moles? For the experiment we used 2.50mL of Na2S2O3. Do I use this to find moles?
Sunday, February 26, 2012 at 9:14pm by Hannah

Chemistry
A. Standardization of Na2S2O3 -Mass of KIO3 in 100mL = 0.09600g -Calculate Molarity of KIO3= ? Please check: 0.09600g/(214.0g/mol)=4.486x 10^-4 mol -4.486 mol/0.1L= 0.004486 M This looks ok to me except for the -4.486. I don't know why the - sign is there unless it's just a ...
Sunday, March 6, 2011 at 11:42pm by DrBob222

CHemistry Please Help. DR. BOBB
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 9:35pm by Sara

Chemistry
How many grams of I2 are present in a solution if 38.55ml of 0.160M Na2S2O3 solution is needed to titrate I2 the solution?
Monday, November 19, 2012 at 2:12am by Michi

Chemistry
How many grams of I2 are present in a solution if 39.85mL of 0.160M Na2S2O3 solution is needed to titrate the I2 Solution
Friday, March 14, 2014 at 1:43am by Jackie

General Chem
What do you call a solution that is maid by mixing solid Na2S2O3 5H20 with NaOH? Also, what is the complete balanced equation for mixing the above solution with an aqueous solution of NaClO? Thanks anyone!
Wednesday, June 22, 2011 at 7:14pm by Mark

Chemistry
A solution was prepared by adding 15mL of 0.129 M KI, 5mL of 0.1 M Na2S2O3, 1mL of starch solution, and 15mL of 0.125 M (NH4)2S2O8. Calculate the concentration of (M) of I in the final mixture before the chemical reaction.
Friday, October 3, 2008 at 1:36pm by Brian

chemistry
Al(OH)3 + 3HCl ==> AlCl3 + 3H2O is already balanced. I think you may have made a typo in the first one. I suspect it is S2O3^2- on the right which is the way I will balance it. 6NaOH + 4S ==> 2Na2S + Na2S2O3 + 3H2O
Sunday, August 28, 2011 at 7:41am by DrBob222

Chemistry
How many milliliters of 0.230 M Na2S2O3 solution are needed to titrate 2.349 g of I2 according to the equation below? I2(aq)+2S2O3^2-(aq)->S4O6^2-(aq)+2I^1-(aq)
Wednesday, October 6, 2010 at 10:29pm by Drew

Chemistry
I had to perform an experiment for rate of reaction. The point of the experiment was to show how changes in reactant concentration, temperature, and catalyst presence can affect the rate of a reaction. The reaction that we studied was H2O2 + 2I^- + 2H^+ -> I2 + 2H2O We had...
Sunday, February 26, 2012 at 2:41pm by Hannah

Chemistry Help Please
Titration of a Sample of Household bleaches: The oxidizing agent in a household bleach is determined by placing 100 mL of distilled water in a 250 mL Erlenmeyer flask and adding 10 mL of the 10% (w/w) KI solution, swirling the contents of the flask to mix the solutions. Add an...
Wednesday, October 22, 2008 at 10:06am by Sara

Chemistry
Several ways. 1. Dissolve the I2 in KI solution. 2. Dissolve the I2 in CCl4, chloroform, or some other non-polar organic solvent. 3. Dissolve the I2 is Na2S2O3. 4. Reverse the polarity of the wires by switching the leads at the battery. etc
Wednesday, October 23, 2013 at 11:55pm by DrBob222

Chemistry
Divide by the smallest to get 1.00 for the lowest number. 0.04/0.04 = 1.00 0.04/0.04 = 1.00 0.06/-0.04 = 1.50 So we would write NaSO1.5 BUT we want whole numbers; therefore, we can multiply by 2 to obtain 2:2:3 for Na2S2O3 which is sodium thiosulfate.
Tuesday, March 27, 2012 at 6:52am by DrBob222

Chemistry
you are given the equation S2O3 + 2H --> S + SO2 + H2O you mix 25 ml of HCl with a concentration of 2 mol/L with 5 mL of Na2S2O3 with a concentration of 0.3 mol/L. what is the concentration of S2O3 and H?
Thursday, October 14, 2010 at 6:28pm by Samantha

chemistry
Suppose a student diluted and titrated a bleach unknown. A single titration was performed which required 14.42 mL of 0.100 M Na2S2O3. The density of the original, undiluted bleach unknown was 1.042 g/mL. calculate the number of moles of ClO- in the sample titrated.
Sunday, October 27, 2013 at 9:38pm by Morgan

Chemisty
If ten drops of 0.3 M HCl are mixed with ten drops of 0.3 M Na2S2O3, what will be the concentration of each chemical in the mixture? Please help, i am pretty sure that the concentration should be 0.3 M but i am not sure if i am supposed to do somthing with the ten drops. Thank...
Wednesday, January 7, 2009 at 10:39pm by Nancy

Analytical Chemistry
What's the .28 M by Na2S2O3.5H2O? Is that molarity of the thiosulfate? Where's the equation. You can't do anything without an equation. You aren't titrating the IO3 directly are you? I presume you may have added KI to the solution, generated I2, and titrating the I2 with the ...
Monday, October 11, 2010 at 10:12pm by DrBob222

Chemistry 1
You made a typo. You meant Na2S2O3, I'm sure. So I changed it below and balanced it. By the way, you need to learn to do this on your own, especially since this one is so simple. The four S atoms on the left have an oxidation number of +8 and they change to +10 on the right. ...
Tuesday, May 13, 2008 at 9:18pm by DrBob222

Chemesitry!
I can't figure how you came up with that number although I tried several combinations of numbers. 2S2O3^2- + I2 ==> I2 + S4O6^2- millimols I2 = 48.50 x 0.1780 = 8.633 milimmols S2O23^2- = twice that= 8.633 x 2 = 17.266 M S2O3^- = mmols/ml = 17.266/100 = .17266 M which ...
Friday, October 5, 2012 at 4:02pm by DrBob222

Chemistry
What concn do you want the stock solution? mols you want = M x L = ? Then 0.40M x mL = 750 x concn. Note: The above is the correct solution to the problem posted; however, I suspect what you meant was how to prepare 750 mL of a stock solution OF (not with) 0.40M Na2S2O3.
Tuesday, September 25, 2012 at 2:50pm by DrBob222

Analytical Chemistry
I apologize for the disjointedness, I pipetted 5 ml of KIO3, 25 ml of H20, 10ml of Acetic acid, and 1.3g of KI I then Titrated the sodium thiosulfate did 3 trials. Trial one gave me 28.22 ml, I then calculated (M) by taking KI 1.3 g/MW(166.00)then dividing that number by (28....
Monday, October 11, 2010 at 10:12pm by Max

chemistry
That helps. I don't know the order in which these test were done; however, here is some back ground that may help you get started. CaF2 is insoluble in water; therefore, CaCl2 + F^- gives a white ppt. AgNO3 reacts with Cl^-, Br^- and I^- producing AgCl (white ppt), AgBr(pale ...
Monday, February 4, 2008 at 6:14pm by DrBob222

Chemisry
The amount of I3–(aq) in a solution can be determined by titration with a solution containing a known concentration of S2O32–(aq) (thiosulfate ion). The determination is based on the net ionic equation Given that it requires 32.9 mL of 0.330 M Na2S2O3(aq) to titrate a 30.0-mL ...
Tuesday, October 1, 2013 at 9:50pm by DeJanee

Chemistry
Convert g CO2 to g C and g H2O to g H. Add grams C and grams H and subtract from total mass to find grams oxygen. Convert g C, g H, g O to moles. moles = grams/molar mass Then find the ratio of the elements to each other. I worked the Na2S2O3 problem for you earlier; this one ...
Monday, October 17, 2011 at 9:21pm by DrBob222

Chemistry
Solutions of sodium thiosulfate are used to dissolve unexposed AgBr (Ksp = 5.0 10-13) in the developing process for black-and-white film. What mass of AgBr can dissolve in 1.40 L of 0.425 M Na2S2O3? Ag+ reacts with S2O32- to form a complex ion. Ag+(aq) + 2 S2O32-(aq)--> Ag(...
Sunday, March 17, 2013 at 3:28am by Howard

chemistry
im sorry.. i dont even know how to ask. maybe if i knew what i was doing i could ask. but we did a lab about halide ions. we used NaF, CaCl, NaBr, and NaI. we used reagents Ca(NO3)2, AgNO3, NH3(aq), Na2S2O3, and starch + NaOCl. we had to tell if a precipitate formed and the ...
Monday, February 4, 2008 at 6:14pm by Amanda

Chemistry
BaS2O3 ==> Ba^+2 + S2O3^-2 Ksp = (Ba^+2)(S2O3^-2) If you call solubility BaS2O3 = S, then S2O3^-2 = S from BaS2O3 and 0.0045 from Na2S2O3 for a total of S+0.0045M. Substitute into Ksp and solve for S. I assume from the hint that you can not make the assumption that S+0.0045...
Monday, April 19, 2010 at 3:07pm by DrBob222

Chemistry
In the reaction between H2O2 and I-, 15 mL of 0.30M KI, 65. mL of 0.10M H2O2 and 19 mL of 0.020M Na2S2O3 were mixed in a flask containing starch and buffer and the total volume was made up to 500mL with distilled water. The solution turned blue (indicating the presence of I2...
Tuesday, March 22, 2011 at 10:11am by Nikita

DrBobb222 : Chemistry HElp...Please Check
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 ...
Tuesday, October 21, 2008 at 9:15pm by Sara

Analytical chemistry
A 25 ml sample of household bleach was diluted to 500 ml in a volumetric flask. An unmeasured excess of potassium iodide was aded to a 20 ml aliquot of the diluted sample; the iodine liberated in the reaction: OCl- + 2I- -> I2 + Cl- + H2O required 34.5 ml of 0.0409 M ...
Tuesday, July 30, 2013 at 8:55am by Gloria

DrBob222 : Chemistry HElp...Please Check
You don't mean the molar mass is 0.03240, you mean the molarity is 0.03240. I get the same figures you do. So the solution of Na2S2O3 is 0.03240 M. By the way, I think you are limited to just the one zero as I have it written and not 0.032400. Since the 27.15 mL, 25.00 mL ...
Tuesday, October 21, 2008 at 9:48pm by DrBob222

Chemistry: please double check...
Please double check one last time have to hand it in tomorrow.Thank-You in Advance. This was the lab experiment: ------------------------------------------- A. Standardization of the Sodium Thiosulfate Solution Make up a standard solution of potassium iodate by accurately “...
Monday, October 27, 2008 at 6:12pm by Saira

chemistry
You mix together in the proper manner the following VOLUMES: 0.0100 M Potassium iodide...9.2 mL 0.0010 M Sodium thiosulfate...6.5 mL Distilled water...16.8 mL 0.0400 M Potassium Bromate...13.9 mL 0.100 M Hydrochloric acid...6.1 mL Using the rate constant and rate equation ...
Saturday, March 2, 2013 at 10:01pm by Cassie

DrBob222 : Chemistry HElp...Please Check
Sorry its not letting me post the entire thing in the other thread .000146612 mols KIO3 x (3 mols I2/1 mol KIO3) x (2 mols S2O3^-2/1 mol I2) mols = .000887972 mols S203^2- Then M S2O3^-2 = .000887972 mols/0.02715 L.M = 0.032400 Therefore the Molar mass of Na2S2O3 is 0.032400
Tuesday, October 21, 2008 at 9:48pm by Sara

Chemistry
Solutions of sodium thiosulfate are used to dissolve unexposed AgBr (Ksp = 5.0 10-13) in the developing process for black-and-white film. What mass of AgBr can dissolve in 1.40 L of 0.425 M Na2S2O3? Ag+ reacts with S2O32- to form a complex ion. Ag+(aq) + 2 S2O32-(aq)--> Ag(...
Sunday, March 17, 2013 at 6:32pm by Howard

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