Thursday
February 11, 2016

# Search: Purity

Number of results: 147

statistics
A study is discussed the purity of oxygen from a certain supplier. Assume that the mean was 99.61 with a standard deviation of 0.08. Assume that the distribution of purity was normal. Below what purity value would you expect to represent the smallest 25% of the population?
December 16, 2011 by shasha

Chemistry
Using atomic masses, If a certain batch of D2O has a purity of 99.75 weight %, what is its purity in atom (actually molecule) %
October 3, 2013 by Jane

Chemistry
We completed a lab and the conclusion write up asks us to describe the purity of the product. What are some things that determine the purity of the product?
June 26, 2013 by hayley

Chemistry
Aldol Condensation What might be the result if you did not add enough Hydrochloric acid and the final pH remained about 7? -Yield would likely increase and the purity of the product would increase -Yield would likely decrease and the purity of the product would decrease -Yield...
October 3, 2015 by Ash

Sample purity
Question: A student spots an unknown sample on a TLC plate and develops it in pentane solvent. Only one spot, for which the Rf value is 0.05, is observed. Is the unknown a pure compound? What can be done to verify the purity of the sample using TLC? My answer: It's not ...
October 15, 2006 by Sheryl

Chemistry
Reaction: C6H11OH(l) ==> C6H10(l) + H2O(l) Calculate the mass of cyclohexanol (C6H11OH) needed to produce 45.0g cyclohexene (C6H10) by reaction if the reaction has a 86.2% yield and the cyclohexanol is 92.3% pure. Usually this problem would be fairly easy, but the purity is...
October 11, 2015 by Faith

chemistry
The purity of a pharmaceutical preparation of sulfanilamide, C6H4N2O2S, can be determined by oxidizing the sulfur to SO2 and bubbling the SO2 through H2O2 to produce H2SO4. The acid is then titrated with standard NaOH. Calculate the purity (%w/w sulfanilamide) given that 1.457...
February 15, 2012 by darren

bio chemistry
1.)prepare 500mM 100 ML HCL (37% purity, density 1.8) 2.) prepare 0.5N 100 mL HCL(37% purity, density 1.8)
March 30, 2011 by hadja

Chemistry: Organic Chemistry
Optically pure 2-octyl sulfonate, a compound with a leaving group comparable to the tosylate and mesylate groups discussed in this chapter, was treated with varying mixtures of dioxane and water as solvent. The optical purity of the resulting 2-octyl alcohol, a solvolysis ...
November 5, 2013 by Kay

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
how can the purity of water be established?
April 30, 2009 by michael

science
how do u find out the purity of sand
November 30, 2006 by alyssa

Chemistry
An iron nail with a mass of 0.750 g was dissolved in dilute sulfuric acid and diluted to 100.0 mL volume. A 10.0 mL aliquot of this solution was then titrated with standard 0.200 M potassium permanganate solution, according to the following equation: MnO4- + H+ +Fe2+ --> ...
January 3, 2016 by Marina

Scince
How do you think you could increase the purity of the nitrogen gas?
December 8, 2010 by AJ

chemistry
can fractional distillation be used to determine purity of a compound?
January 25, 2011 by ben

chemistry
prepare 500mM 100 ML HCL (37% purity, density 1.8)
March 30, 2011 by Anonymous

biology
How do I calculate protein concentration if I know the purity is 97.3% and MW = 2666.31 kDA Thanks
July 17, 2012 by Jenni

biology
How do I calculate protein concentration if I know the purity is 97.3% and MW = 2666.31 kDA Thanks
July 17, 2012 by Jenni

plz correct this line ..eng
but his purity is not last long as he start growing
October 21, 2010 by Sana

pharmacy
suggest a technique , other than tlc, to confirm the purity of the samples
April 19, 2012 by pavan

Biochemical methods
Expain the preparation of 250ml of 2.5% v/v H3PO4 (MW=98.0,density=1.71,%purity=85%
February 9, 2016 by Fash

o-chem
explain how the rate of crystal growth can affect the purity of a recrystallized compound
October 7, 2008 by David

o-chem
explain how the rate of crystal growth can affect the purity of a recrystallized compound
October 7, 2008 by David

Organic Chemistry
What advantages does H NMR have over melting point in the determination of purity?
April 19, 2011 by anon

TLC purity
Question: A student spots an unknown sample on a TLC plate and develops it in dichloromethane solvent. Only one spot, for which the Rf value is 0.95, is observed. Does this indicate that the unknown material is a pure compound? What can be done to verify the purity of the ...
October 13, 2006 by Sheryl

Chemistry
Can anyone please tell me what can you say about the purity of the compound extracted based on your TLC results? Thanks
February 9, 2010 by Andy

Chemistry 110
4. The electrical conductivity of deionized water is commonly used as an index of its purity. Explain.
November 9, 2010 by kim k

chemistry
What is the percentage purity of sample if 3.92g of mohr's salt react completely with 50 ml N/10 Kmno4 solution
June 25, 2012 by ketaki

chemistry
what weight of na2c03 of 95% purity would be required to neutralize 45.6ml of 0.235N acid? Who Helps
January 27, 2013 by Fai

Sociology
What exactly is "cultural purity?" I think I understand the concept, but I'm having a hard time putting it into words.
October 4, 2007 by Lindsay

Chemistry
Calculate the total mass of aluminum, with 90% purity, required to produce 448g of iron in the process Fe2O3 + 2 Al = Al2O3 + 2 Fe
January 21, 2016 by Cindy

Chemistry
Hi, I'm a little stuck on this problem: Find the pH of the Hydrochloric acid solution when 5.0 mL of concentrated HCl, with a specific gravity of 1.18 and has 37% (w/w) purity is diluted to 2.0L
November 11, 2013 by T

Chemistry
This is about spectrometry. How would the presence of salicylic acid affect the results of the spectrophotometric determination of the purity of ASA? Why? I don't know how you conducted the experiment but I assume you measured a peak in the absorption spectrum of ASA. Since ...
April 25, 2007 by Brissa

Chemistry
how many millimeter should be taken out to prepare 0.5 normal HCL solution of 200 ml. density=1.18, purity 37% please response soon
June 15, 2014 by Sparky

Purity
The question asked is: Using yur results as a guide, comment on the purity of the material in the green and yellow bands. (from a TLC of spinach extraction pigments.) I'm not quite sure what they want here and my plate is in the lab, not here. There were yellow and green bands...
October 22, 2006 by Sheryl

Necklaces
Is there a big difference between 10k and 14k gold chains? My husband wants a chain he can wear all the time. Should I get 10k or 14k? http://www.24carat.co.uk/whyeighteencaratgoldisbetter.html http://en.wikipedia.org/wiki/Carat_(purity) Thank you for using the Jiskha Homework...
December 12, 2006 by Sharon

Chemistry
On calcination 80g of a marble were obtained 42 g of calcium oxide. The degree of purity of marble?
January 21, 2016 by Jessica

Science
One of the most common commercial methods for the production of pure silicon that is to be used for the manufacture of semiconductors is the Siemens process (see Figure P5.3.5) of chemical vapor deposition (CVD). A chamber contains a heated silicon rod and a mixture of high-...
June 9, 2015 by Tyla

chemistry
50% purity NAOH liquid . if the density is 1.53 . so one liter hou much NAOH is here ?
October 21, 2009 by jeet

college chemistry
Describe the preparation of 250cm^3 of 0.05M H2SO4 given the following stock bottle solution. %purity=98 Specific gravity=1.84 Molecular weight=98
October 28, 2015 by Ezinase

chemistry
I did a lab about melting point. It is asking me for the purity of the compounds? How do I find it? Do I use melting points or percent yield?
October 5, 2010 by Yoo

chemistry
3) The melting point range of an unknown substance was determined to be 120-180 degree celcius. what can you tell about the purity of the unknown
July 18, 2012 by ama

physics
As part of a sinister plot, I connect a piece of high-purity GaAs 1 cm long to a 9 V battery, at room temperature. What is the resulting drift velocity of the electrons? Your answer should be in cm/s
December 21, 2013 by Henry III

chemistry
What weight of na2co3 of 95% purity would be required to neutralize 45.6ml of 0.235n acid? I want you step by step clearly explain answer 0.5978gm
January 27, 2013 by Fai

chemistry
it is desired to prepare 250.0mL of a standard solution having a concentration of 0.1000M AgNo3. How many grams of a sample of AgNO3 of 98.8% purity are required for this purpose?
March 25, 2010 by T

chemistry
it is desired to prepare 250.0mL of a standard solution having a concentration of 0.1000M AgNo3. How many grams of a sample of AgNO3 of 98.8% purity are required for this purpose?
March 25, 2010 by T

Chemistry
Hi, This may sound like a dumb question but I am stuck. I have worked out everything from a titration and I am now trying to work out my overall % purity. It is 86.0% +/- 1.3% What will 86.0% + 1.3% be and what will 86.0% - 1.3% be?
October 26, 2011 by Paula

english 4
The swans in "The Wild Swans at Coole" most likely symbolize a. faithlessness b. fragility and purity c. the flight form life's problems d. beauty and timelessness thanks
May 10, 2013 by working hard

U.S.History
Prohibitions and purity crusaders shared the goal of a. making charity "scientific" b. redistributing the nation's wealth c. ending immigration from Asia d. improving the personal behavior of individuals i'm not 100% sure but i think D
February 19, 2009 by y912f

history
I have a turquiose ring, round stamped with what I believe to be HH. The first H is very clear although the second letter almost looks like a mistrike H, could be a worn F, E, etc... what do the letters mean??? There are no purity markings that I can see.
June 1, 2008 by Becky

chemistry
Suppose that 1.78 x 10^3 kg of Fe are obtained from a 5.80 x 10^3 kg sample of Fe2O3. Assuming that the reaction goes to completion, what is the percent purity of Fe2O3 in the original sample?
January 31, 2012 by Joe

chemistry
when 5g of impure sample of CH4 is completely combusted, 9g of H2O was produced.what is the percentage purity of the sample of CH4
March 11, 2015 by john

Chemistry
When you use UV Vis to determine the purity of the product- how does knowing the amount of salicylic acid help? Do you only use this when you know (after adding Fe3+) that the aspirin isn't pure? I know there is a very simple answer to this question...
June 9, 2012 by mish

Chemistry
How can i explain hw i can prepare a 250ml of2.5M of HCl acid from;molecular weight of acid 36.5g\mole;density of acid 1.19g\ml and degree of purity of acid 37%
December 19, 2014 by Ayuk

Chemistry
8.5g of sample of iron required just 75cm3 of 3.00M HCl to dissolve it and give a neutral solution.Calculate the percentage purity of the sample of iron.
November 16, 2014 by Kazembeous

chemistry
Explain why the yield of ester is relatively low? How to improve the yield and the purity of ester?
June 15, 2011 by Make

Chemistry
1.2048g sample of impure Na2CO3 is dissolved and allowed to react with a solution of CaCl2 resulting CaCO3 after precipitation, filtaration and drying was found to weight 1.0362g. calculate the percentage purity of Na2CO3
February 14, 2015 by Ana

Chemestry
A sample of crude potassium iodide was analyzed using this reaction (not balanced): I- + SO42- I2 + H2S (acid solution) If a 4.19-g sample of crude KI produced 1.33 g of iodine, what is the percent purity of the KI?
November 23, 2014 by Santiago

chemistry
6.0g of impure and hydrous Na2SO4 were made up to 1dm^3 of solution neutralize 22.20cm^3 of 0.1mol/dm^3 of HCL.calculate: a)concentration of Na2CO3 in mol/dm^3. b)concentration of Na2CO3 in gram/dm^3. c)percentage purity in carbon.
January 28, 2012 by faith

chemistry
6.0g of impure and hydrous Na2SO4 were made up to 1dm^3 of solution neutralize 22.20cm^3 of 0.1mol/dm^3 of HCL.calculate: a)concentration of Na2CO3 in mol/dm^3. b)concentration of Na2CO3 in gram/dm^3. c)percentage purity in carbon.
January 28, 2012 by faith

Chemistry
Concentrated hydrochloric acid has a purity of 36.0% by mass. The density of the concentrated of the acid is 1.19 g/mL.Determine the molar concentration of this acid..please show me the solution...
July 5, 2014 by Syam

Jim
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 Chemistry

History
What was one of the main teachings of Siddhartha Gautama? A. Respect for one’s elders ensures social order. B. Strict caste rules help ensure spiritual purity. C. Priests will help lead you to enlightenment. D. Avoid desire because it causes suffering --------is it D
August 23, 2012 by Keisha

CHEMISTRY
Fe2O3 + 3CO= 2Fe + 3CO2, SUPPOSE THAT 1.64kg OF Fe ARE OBTAINED FROM A 2.62kg SAMPLE OF Fe2O3(ORE). ASSUMING THE REACTION IS COMPLETE, WHAT IS THE PERCENT PURITY OF THE Fe2O3 IN THE ORIGINAL SAMPLE?
April 17, 2011 by BECKY

chemistry
Fe2O3+ 3CO=2Fe+3Co2, suppose that 1.64kg of Fe are obtained from a 2.62kg sample of Fe2O3 (ore). assuming that the reaction goes to completion, what is the percent purity of the Fe2O3 in the original sample.
April 19, 2011 by becky

Chemistry
If the radiation of an automobile contains 12L of water, how much would the freezing point be lowered by addition of 5 kg of prestone (glycol, C2H4(OH2))? How many kg of zerone (methyl alcohol, CH3OH) would be required to produce the same result? assume 100% purity .
March 6, 2010 by ray

A material has an optical purity of 50%. How much of each of the enantiomers is present. The R enantiomer of a material has rotation of +35. what is the rotation of the S enantiomers.
October 8, 2014 by Josh

chem
he literature value for the melting point of aspirin is 135°C. Suppose that a sample of aspirin prepared in Experiment 41 melts over the temperature range 125–128°C. What does this result suggest about the purity of this sample of aspirin?
May 10, 2011 by maribel

Chemistry
Sodium hypochlorite, NaClO, is added as a disinfectant to the water supply. You are analyzing a sample from the supplier to verify its purity and you prepare to titrate 250.0 mL of a solution containing 1.86 g of NaClO with a 1.00 M HCl solution. What is the pH of the solution...
February 13, 2012 by Rosa

math Steve form your help
50gm of a mixture of ca(OH)2 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 % purity of ca(OH)2 The answer 41.35% Who helps me step by step
December 29, 2013 by Fai

chemistry
A 0.1028 g impure sample consists of Na2CO3 was analyzed by the Volhard method. After adding 50.00 mL of 0.06208 M AgNO3, the sample was back titrated with 0.06261 M KSCN, requiring 28.36 mL to reach the end point. Report the purity of the Na2CO3 sample
November 4, 2015 by yun

Chemistry
14 carat gold has a purity of 58.3% How many moles of gold are in 124 grams of 14 carat gold ?! Answer in units of moles. how would yu do this problem ?! explain pleasee. !
July 26, 2010 by Nicole

Chem
To purify acetanilide by a recrystallization procedure. a) Describe how you would decide what solvent to use in order to accomplish this objective. b) How you would calculate the effeciency of your recrystallization procedure with respect to; --- Improvement in purity across ...
September 17, 2014 by JuYoung

Chemistry
A student was given a 2.45 g of impure potassium sulfate (K2SO4) sample. He dissolved this sample in 100 mL of water first and then added some barium chloride (BaCl2) solution. A 2.15 g of BaSO4 precipitate was obtained at the end of the reaction. What is the percent purity of...
November 22, 2014 by Anonymous

Chemistry
Na2CO3 reacts with H2SO4 to give respective salt water and carbon dioxide. Calculate the mass of pure salt formed when 300 g of Na2CO3 of 80% purity reacts with H2SO4
March 24, 2013 by Aurab

chemistry
you have two sample of mannitol .one melted between 168-169 c and the other melted between 161-168 .which sample has the greater purity? why?
February 15, 2014 by Abeer

Chemistry
A 2.00 g impure sample of MgO (molar mass 40.3 grams) was completely dissolved in 50.0 mL of 1.000 M H2SO4. The excess acid was back-titrated with 25.0 mL of 0.800 M NaOH. Calculate the percent purity of the MgO sample. [80.6 %] MgO(s) + H2SO4(aq) MgSO4(aq) + H2O(l)
October 11, 2015 by Anonymous

Chemistry!!!
1.)The silica that makes up the stationary phase in TLC chromatophraphy is more polar than the mobile phase. What then might the relative positions of the analgesics on the developed TLC plate tell you about the polarity of these molecules? Does this match the expectations ...
July 1, 2013 by Kris

Symbolism
1. What does the color white symbolize? Answer: Purity and innocence 2. What does Santa Clause symbolize? Answer: Christmas 3. What does a cupid symbolize? Answer: Love 4. The image of the lion lying doen with the lamb symbolizes what? Answer: ??? Can someone check if my ...
January 14, 2009 by Larry

chemistry
14 carat gold has a purity of 58.3%. how many moles of gold are in 155 grams of 14 carat gold? answer in units of moles.
September 8, 2010 by Jordyn

chem
14 carat gold has a purity of 58.3%. How many moles of gold are in 137 grams of 14 carat gold? Answer in units of moles.
February 1, 2011 by pho le

AP Chemistry
14 carat gold has a purity of 58.3%. How many moles of gold are in 172 grams of 14 carat gold? Answer in units of moles
September 19, 2012 by Lacey

chemistry
Urgent. The melting point of pure acetylsalicylic acid is 135 degrees celsius. Comment on the purity of your product based on its melting point range. My melting point range was 105-115. I do not even know where to start for this question. Could you please help?
March 23, 2010 by Lee

Chemistry/Quantitive Anaylsis
Before determining the amount of sodium carbonate in a sample by titration with standard hydrochloric avid the anaylst decide to check the procedure by analyzing a known sample of 98.75 (w/w)% purity. Five replicate determinations of the known gave the following results: 98.71...
October 14, 2012 by Brittany

physical chemistry
Please prepare 0.5L of 1.2M HCl in 50% (v/v) aqueous methanol. The details of HCl are as follows: Hydrochloric acid: Purity : 36%-38% Density : 1.18g/mL Physical state : liquid Molecular weight : 36.42 g/mol Describe the procedures and apparatus you need to use for the ...
November 22, 2014 by elvy

Chemistry
1)What could have caused the impurity in the sodium hydroxide solution? 2)Why was it necessary to dilute the hydrochloric acid before carrying out the titration? This was a question from a titration practical in which we had to dilute HCL then use that along with 25cm3 of NaOH...
October 18, 2014 by Anon

chemistry
Please help me with my formal report on "Potentiometric Determination of the Purity and Dissociation Constant of Potassium Hydrogen Phthalate" Please give me links to websites that could be used for my reference... In addition, please do suggest books that discuss ...
August 19, 2007 by Smiley

chem
One of the reactions that occurs in a blast furnace, where iron ore is converted to cast iron, is below. Fe2O3 + 3 CO 2 Fe + 3 CO2 Suppose that 1.86 103 kg of Fe are obtained from a 5.98 103 kg sample of Fe2O3. Assuming that the reaction goes to completion, what is the percent...
August 7, 2012 by Shawn

analytical chemistry
at elevated temperature, NaHCO3 (83.98g/mol) is converted quantitatively to Na2CO3 (105.98g/mol).Ignition of 0.3592g sample of an antacid tablet containing NaHCO3 and non volatile impurities yielded a residue weighing 0.2362g. Calculate the percent purity of the sample.
January 26, 2014 by Anonymous

BMB
1.You have a mixture of protein A and protein B in a buffer of pH 7. The pI of protein A is 3 and the pI of protein B is 8. The molecular weight is the same. (a) What kind of column chromatograph would you use to separate them? Explain your answer in 2-3 sentences. (b) Can you...
November 4, 2008 by jess

Chemistry
The melting point of aspirin : 128-137Celsius degree. The melting point of the crude aspirin was measured to be 128 Celsius degree. What does it indicate about the purity of the product?
December 5, 2010 by Cynthia

chemistry
In choosing a primary standard we generally choose something that 1. All of these are properties we want in a primary standard. 2. has a low percent purity. 3. None of these are properties we want in a primary standard. 4. has several different possible reaction pathways. 5. ...
September 19, 2012 by cheri

Chemistry
One of the reactions that occurs in a blast furnace, in which iron ore is converted to cast iron, is Fe2O3 + 3CO → 2Fe + 3CO2 Suppose that 1.59 × 103 kg of Fe is obtained from a 2.54 × 103 kg sample of Fe2O3. Assuming that the reaction goes to completion, what is the ...
September 9, 2015 by Helga

Chem
Calculate the percent yield of eugenol obtained considering the fact that clove oil is approximately 16-19 % clove by weight of cloves. isolated eugenol=061g purity of eugenol in clove oil=99.6% (based on clove oil gas chromatograph) Estimate the % yeild for eugenol.
November 28, 2010 by Jason

Chemistry
As a purity check for industrial diamonds, a 22 - carat diamond (1 carat = 0.2g) is heated to 63 degrees C and immersed in 26g of water in a constant pressure calorimeter. The initial temperature of the water is 23 degrees C. Calculate the ΔT of the water and of the ...
January 12, 2015 by Jon

SCIENCE/CHEM
the purity of zinc is to be determined by measuring the amount of hydrogen formed when a weighed sample of zinc reacts with an excess of HCL acid.the sample weighs 0.198 grams. what amount of hydrogen gas at STP will be obtained if the zinc is 100% pure? need a metric answer ...
May 12, 2010 by Andy

chemistry
I did a chemistry lab on polarimetry where we separated two enantiomers into individual salts and then used a polarimeter to determine the specific rotation and optical purity. What is the relationship of the proline salts to one another? i said that being enantiomers, they ...
March 31, 2008 by laura

analogies
1. Lampoon : Ridicule a. hyperbole : exaggerate b. hiatus : continue c. trepidation : fear d. levity : depreciate e. debate : vacillate My thinking: I think it is A, because to use lampoon is to ridicule and to use hyperbole is to exaggerate 2. Depraved : Purity a. loquacious...
October 27, 2006 by Anonymous

science
6g of impure NaOH was dissolved in 100ml of a solution.0.25molar solution of the base utilize 27.6ml of the solution containing 6g of trioxonitrate(5)acid.calculate (a)molar concentration of acid (b) molar concentration of base (c) mass of the base (d) % purity of the base
January 19, 2013 by chm 101

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

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