Wednesday
July 30, 2014

Search: Purity

Number of results: 118

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

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
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

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

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

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 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
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
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 ones 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

chem
he literature value for the melting point of aspirin is 135C. Suppose that a sample of aspirin prepared in Experiment 41 melts over the temperature range 125128C. 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
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

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!!!
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

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

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

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

Chemistry
The relative amount of gold in an alloy is commonly expressed in units of carats. Pure gold is 24 carats, and the percentage of gold in an alloy is given as a percentage of this value. For example, an alloy that is 50 percent gold is 12 carats. State the purity of the gold ...
August 18, 2013 by Anonymous

chemistry
discuss if and when melting points can be used to determine the purity of organic and inorganic compounds and if and when melting points can be used to identify organic and inorganic compounds.
January 18, 2011 by ben

OChem
1. if and when boiling points can be used to determine the purity of organic compounds. 2. if and when boiling points can be used to identify organic compounds. 3. when can fractional distillation be used to separate organic compounds
September 23, 2012 by Mia

religious studies
Describe Purity Balls and explain their function within their own religious community. Also, discuss how this ritual fulfills the four functions of ritual (Four functions of ritual are: Orients participants to space & time; Connects participants to divine; Connects ...
September 27, 2010 by Boby

biochemistry
Enzyme X is a highly pigmented protein that imparts the characteristic color to certain blue-green algae. It also facilitates a reaction necessary to the survival of this species; we can follow the kinetics of this reaction by measuring the conversion of Substance X to ...
November 3, 2012 by Ama

biochemistry
Enzyme X is a highly pigmented protein that imparts the characteristic color to certain blue-green algae. It also facilitates a reaction necessary to the survival of this species; we can follow the kinetics of this reaction by measuring the conversion of Substance X to ...
November 2, 2012 by Ama

World Religions
Islam Ihram is the word given to the special state in which pilgrims are expected to live while they are on Hajj - the prilgrimage to Makkah. They are expected to live pure lives, and are not supposed to swear or quarrel. Any sexual relationship is forbidden and as a sign of ...
January 9, 2009 by Lisa

Chemistry
When 0.40 g of impure zinc reacted with an excess of hydrochloric acid, 127 mL of hydrogen was collected over water at 10 degress C The external pressure was 737.7 Torr. a) What volume would the dry hydrogen occupy at 1.00 atm and 298 K ? b) What amount (in moles) of H2 was ...
December 13, 2012 by Sandy

chemistry
an impure sample of oxalic acid C2O4H2, with a mass of 0.465g, is dissolved in water. a few drops of phenolphthalein indicator solution are added, and the solution is titrated with 0.190 mol/L aqueous sodium hydroxide held in a burette. the solutointurns pink when 49.5mL of ...
December 24, 2010 by tarkan

science
1)effects of impurities on the boiling point of an organic compound. 2) purposes why melting points are determined. 3)suppose i am taking a melting point and the compound disappears, what must i do? Have you put any thought into these or do you expect us to do your homework? ...
August 15, 2007 by bugalo

Chemistry
A 0.4584 g sample of impure zinc chloride, ZnCl2, FW = 136.3 g/mole, was dissolved in water and excess silver nitrate was added to the solution. The mass of the dry silver chloride, AgCl, FW = 143.3 g/mole, produced was 0.8564 g. The balanced precipitation is: ZnCl2 (aq) + 2 ...
October 16, 2011 by Anonymous

Algebra 2
The purity of gold is measured in karats. Twenty-four karat gold is pure gold and k karat gold is k/24 gold by mass. One piece of 16-karat gld jewelry has a mass of 30 grams and another piece of 10-karat gold jewelry has a mass of 40 grams. Find the number of grams in the ...
January 30, 2011 by Jay

Algebra
The purity of gold is measured in karats. Twenty-four karat gold is pure gold and k karat gold is k/24 gold by mass. One piece of 16-karat gold jewelry has a mass of 30 grams and another piece of 10-karat gold jewelry has a mass of 40 grams. Find the number of grams in the ...
January 26, 2011 by Laur

Chemistry
Hi everyone, I have been trying to figure out this titration equation all day and for some reason I am stumped. Here is the question in full: Potassium hydrogen phthalate, KHP, can be obtained in high purity and is used to determine the concentrations of solutions of strong ...
November 29, 2012 by jo

College Chemistry
About half the world's production of pigments for paints involves the formation of white TiO2. It is made on a large scale by the chloride process , starting with ores containing only small amounts of rutile, TiO2. The ore is treated with chlorine and carbon. this produces ...
October 16, 2011 by Anonymous

biochemistry
You have purifiedLDH using affinity chromatography. Using the bradford assay you determined the total protein concentration of the column fraction to be 10 mg/ml in a final volume of 2.4 ml. You diluted some of your column fraction to 1 mg/ml using SDS Page sample loading ...
December 9, 2013 by lacy

chemistry
You have purifiedLDH using affinity chromatography. Using the bradford assay you determined the total protein concentration of the column fraction to be 10 mg/ml in a final volume of 2.4 ml. You diluted some of your column fraction to 1 mg/ml using SDS Page sample loading ...
December 9, 2013 by lacy

English
I urgently need you to check these descriptions I wrote myself, mailny grammar and word choice. Thank you. 1)Photo A shows people in a business environment. There three women and a man sitting at a desk while another man is standing. This is writing something on a notebook. 2...
September 10, 2011 by Henry2

English+ poetry+ confused+ check!
The way a crow Shook down on me The dust of snow From a hemlock tree Has given my heart A change of mood And saved some part Of a day I had rued. Scan the poem and determine the rhythm. is it a sonnet? or do they want this: A crow symbolizes death, snow is white and something ...
December 19, 2006 by Anonymous

College Chemistry
i was told to Convert 1 metric ton to grams ore then to grams TiO2 (using the 0.75% in the ore), then to g TiCl4 (using the 70%%) and finally to TiO2 final product (using the 93.0%)for the following questions, but im stuck after converting the metric ton to grams About half ...
October 17, 2011 by Anonymous

Enaglish
Please check this paraph We know that every man commits sins. There is no way that we can Undo our mistakes. It is only possible through the salvation . God likes those people who seeks His mighty forgivenss after committing sins, He dont like those who stick to their ...
October 21, 2010 by Anonymous

US History
Please help me with these: (I finally finished English 2, and am about to get halfway through this!) 4. Prohibitionists 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...
October 17, 2010 by mysterychicken

Pages: 1 | 2 | Next>>

Search
Members