Sunday
April 20, 2014

Search: Purity

Number of results: 233

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?
Friday, December 16, 2011 at 11:08am by shasha

Sociology
Cultural purity would indicate the strict maintenance of the customs and ethics of a particular society. Example, in America it would be extremely difficult to maintain any sort of cultural purity since the "melting pot" ideal is the basis of this society. In any nation that ...
Thursday, October 4, 2007 at 10:54pm by GuruBlue

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) %
Thursday, October 3, 2013 at 5:30pm by Jane

chemistry
I think the first one wants you to discuss IF melting points can be used to determine purity and if so, then how. I would think a discussion of the melting point range would be useful (what range indicates high purity and what range indicates low purity) as well as something ...
Tuesday, January 18, 2011 at 3:07pm by DrBob222

TLC purity
@ Johnny: TLC stands for thin layer chromatography. TLC is used for monitoring the process of a reaction, identifying compounds, and determining the purity of a substance. When conducting an experiment on TLC, you can determine the purity of an unknown analgesic by examining ...
Friday, October 13, 2006 at 11:29pm by Taylor

TLC purity
@ Johnny: TLC stands for thin layer chromatography. TLC is used for monitoring the process of a reaction, identifying compounds, and determining the purity of a substance. When conducting an experiment on TLC, you can determine the purity of an unknown analgesic by examining ...
Friday, October 13, 2006 at 11:29pm by Taylor

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?
Wednesday, June 26, 2013 at 7:17pm by hayley

TLC purity
TLC is used for thin layer chromatography, not for determining purity.
Friday, October 13, 2006 at 11:29pm by johnny

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 ...
Sunday, October 15, 2006 at 4:16pm 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...
Wednesday, February 15, 2012 at 5:26pm 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)
Wednesday, March 30, 2011 at 10:20pm by hadja

Science
Please try some of the following links: http://search.yahoo.com/search?fr=mcafee&p=how+to+increase+the+purity+of+nitrogen+gas Sra
Wednesday, December 8, 2010 at 9:34pm by SraJMcGin

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 ...
Tuesday, November 5, 2013 at 2:58pm by Kay

religious studies
Begin with some of the following links: http://search.yahoo.com/search?fr=mcafee&p=describe+Purity+Balls+%26+explain+their+function Sra
Monday, September 27, 2010 at 1:53am by SraJMcGin

TLC purity
You're all gay
Friday, October 13, 2006 at 11:29pm by Emrah

chemistry
how can the purity of water be established?
Thursday, April 30, 2009 at 6:37am by michael

Chemistry
The copper that is alloyed with gold (24 k is pure gold; 18 k is 18/24 purity and 14 is 14/24 purity) reacts with the acid akin and other body fluids to give a green (sometimes black) compound of copper. It has been reported that many people can switch from 14 k gold to 18 k ...
Monday, March 9, 2009 at 4:45pm by DrBob222

science
how do u find out the purity of sand
Thursday, November 30, 2006 at 8:02pm by alyssa

Scince
How do you think you could increase the purity of the nitrogen gas?
Wednesday, December 8, 2010 at 9:34pm by AJ

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 ...
Saturday, March 24, 2007 at 11:33am by Jim

chemistry
can fractional distillation be used to determine purity of a compound?
Tuesday, January 25, 2011 at 5:28pm by ben

Essay on purity of heart
we are all forgetting moral values
Sunday, July 8, 2007 at 1:51am by shweta

Essay on purity of heart
we are all forgetting moral values
Sunday, July 8, 2007 at 1:51am by shweta

Chemistry
I don't think anyone here will be willing to write a three or four page report but allow me to give you some hints. You really don't know the purity of many of the salts of copper; however, starting with copper wire or copper turnings might be a good possibility. Copper wire ...
Tuesday, October 12, 2010 at 7:52pm by DrBob222

Chemistry
Contamination talks about the purity. Neutrality is based on PH isnt it?
Sunday, October 25, 2009 at 6:20pm by Anonymous

plz correct this line ..eng
but his purity is not last long as he start growing
Thursday, October 21, 2010 at 8:43pm by Sana

plz correct this line ..eng
but his purity did not last long as he started growing
Thursday, October 21, 2010 at 8:43pm by Ms. Sue

pharmacy
suggest a technique , other than tlc, to confirm the purity of the samples
Thursday, April 19, 2012 at 7:12am by pavan

o-chem
explain how the rate of crystal growth can affect the purity of a recrystallized compound
Tuesday, October 7, 2008 at 3:40am by David

o-chem
explain how the rate of crystal growth can affect the purity of a recrystallized compound
Tuesday, October 7, 2008 at 4:07am by David

chemistry
prepare 500mM 100 ML HCL (37% purity, density 1.8)
Wednesday, March 30, 2011 at 11:26pm by Anonymous

chemistry
How sharp the melting point is and how close to the accepeted melting point the value you find are indicators of how pure the sample might be. Thus a sharp melting point that agrees with the accepted value would indicate a high purity sample. Even better would be to have a ...
Tuesday, October 5, 2010 at 1:19am by Dr Russ

Organic Chemistry
What advantages does H NMR have over melting point in the determination of purity?
Tuesday, April 19, 2011 at 3:32am by anon

biology
How do I calculate protein concentration if I know the purity is 97.3% and MW = 2666.31 kDA Thanks
Tuesday, July 17, 2012 at 12:14pm by Jenni

biology
How do I calculate protein concentration if I know the purity is 97.3% and MW = 2666.31 kDA Thanks
Tuesday, July 17, 2012 at 12:41pm by Jenni

Chemistry
Can anyone please tell me what can you say about the purity of the compound extracted based on your TLC results? Thanks
Tuesday, February 9, 2010 at 6:45pm by Andy

Chemistry 110
4. The electrical conductivity of deionized water is commonly used as an index of its purity. Explain.
Tuesday, November 9, 2010 at 2:15pm by kim k

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 ...
Friday, October 13, 2006 at 11:29pm by Sheryl

Sample purity
haha i seriously have the same chem question nearly 3 years after you posted that
Sunday, October 15, 2006 at 4:16pm by bob the chemist

Sociology
What exactly is "cultural purity?" I think I understand the concept, but I'm having a hard time putting it into words.
Thursday, October 4, 2007 at 10:54pm by Lindsay

college algebra word problem
Since there are different quantities of each purity wouldn't there be an x and a y in the equation instead of both being x?
Wednesday, February 25, 2009 at 6:37pm by amy

chemistry
what weight of na2c03 of 95% purity would be required to neutralize 45.6ml of 0.235N acid? Who Helps
Sunday, January 27, 2013 at 2:14pm by Fai

chemistry
What is the percentage purity of sample if 3.92g of mohr's salt react completely with 50 ml N/10 Kmno4 solution
Monday, June 25, 2012 at 3:34am by ketaki

Chemistry
I also have the density of the distillate. I don't know what the initial and final purity of the mixes is, we were just told we were distilling "unpurified" acetone.
Tuesday, October 23, 2012 at 9:37pm by helllp

Chemistry
Check the numbers in your post. Either I'm on the fast track to nowhere or there is at least one wrong number. I'm getting 150+% purity and that can't be.
Tuesday, December 2, 2008 at 10:22pm by DrBob222

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...
Sunday, October 22, 2006 at 3:01pm by Sheryl

Chemistry
density? temperature? are you using pure or denatured alcohol? purity of alcohol? other?
Sunday, November 24, 2013 at 6:45pm by DrBob222

TLC purity
Emrah- plz, for the love of god go back and finish grade school. also, thanks for the answer sheryl, helped me out a bit.
Friday, October 13, 2006 at 11:29pm by Jamaal

Chemistry
Ok, thank you very much for trying. It was to do with a whole load of calculations working out the titration and purity etc. I think I'll just leave it and ask my teacher. Thank you again. Paula
Wednesday, October 26, 2011 at 1:22pm by Paula

chemistry
50% purity NAOH liquid . if the density is 1.53 . so one liter hou much NAOH is here ?
Wednesday, October 21, 2009 at 5:28am 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?
Tuesday, October 5, 2010 at 1:19am by Yoo

chemistry
The smaller melting range is the higher purity. That's because of colligative properties (the decrease in melting point with added impurity)
Saturday, February 15, 2014 at 6:24am by DrBob222

chemistry
Working in N has real advantages over using M but most schools don't teach that now. mL x N x milliequivalent weight = g 50 x 0.1 x 0.392 = ?g (?g/3.92)*100 = % purity.
Monday, June 25, 2012 at 3:34am by DrBob222

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 ...
Wednesday, April 25, 2007 at 12:55am by Brissa

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...
Tuesday, December 12, 2006 at 12:54pm by Sharon

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
Wednesday, July 18, 2012 at 6:29am by ama

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
Monday, November 11, 2013 at 8:08pm by T

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
Friday, May 10, 2013 at 11:56am by working hard

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?
Thursday, March 25, 2010 at 4:33am 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?
Thursday, March 25, 2010 at 4:34am by T

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
Sunday, January 27, 2013 at 2:39pm by Fai

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
Thursday, February 19, 2009 at 5:22pm by y912f

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
Saturday, December 21, 2013 at 3:53am by Henry III

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.
Sunday, June 1, 2008 at 1:00am by Becky

College Chem
heat=heatfusionethanol*mass look up the heat of fusion for ethanol. It is common to specify what purity the ethanol is, 100% is very rare.
Monday, September 27, 2010 at 4:12pm by bobpursley

chemistry
Explain why the yield of ester is relatively low? How to improve the yield and the purity of ester?
Wednesday, June 15, 2011 at 6:09am by Make

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...
Saturday, June 9, 2012 at 1:54am by mish

science
Purity, pH, bacteria count, contaminates (mercury, etc). You need to amplify your question. In the West, we settle for lessor water quality vs availability. There are not many mountain streams of pure water in Utah and California.
Tuesday, November 6, 2007 at 10:43am by bobpursley

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
Thursday, August 23, 2012 at 8:40pm by Keisha

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?
Wednesday, October 26, 2011 at 1:22pm by Paula

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?
Sunday, April 17, 2011 at 11:50am by BECKY

Chemistry
What do you define as strong or stronger? I think both are about the same ionizing property, which at the 100% purity, is not high for H2SO4 or H2S2O7. Fuming H2SO4 (H2S2O7) generally is more corrosive because it contains SO3 gas.
Friday, November 25, 2011 at 3:19pm by DrBob222

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.
Tuesday, April 19, 2011 at 12:26pm by becky

CHEMISTRY
one needs one mole of ironIIoxide to make two moles of iron. MolesIron obtained: 1640/atomicmassFe molesFe2O3: one half that. grams Fe2O3: moles*molmass percent purity: gramsFe2O3/2620
Sunday, April 17, 2011 at 11:50am by bobpursley

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?
Tuesday, May 10, 2011 at 9:57am by maribel

11th grade u.s. history
also remember that there are two groups, Puritans, and more religiously zealous puritains called Seperatists. The Seperatists were the puritans who went to the new world (america) and founded Massachusettes to create a land of religious oppurtunity and purity.
Monday, September 1, 2008 at 10:12pm by josh

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...
Monday, February 13, 2012 at 2:50am by Rosa

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 .
Saturday, March 6, 2010 at 9:38am by ray

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?
Tuesday, January 31, 2012 at 11:20am by Joe

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
Sunday, March 24, 2013 at 2:46pm 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?
Saturday, February 15, 2014 at 6:24am by Abeer

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 ...
Saturday, March 24, 2007 at 12:37am by Chemistry

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.
Saturday, January 28, 2012 at 7:15am 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.
Saturday, January 28, 2012 at 7:15am by faith

chem
1. It will be obvious when the first crystal melts. It may not be a "drop" as such so it isn't literal but you can't miss it. As for the literature mp, no, I wouldn't trust them for your samples. They will be good boundaries to guide you but the mp of your samples will depend ...
Monday, September 3, 2007 at 11:17pm by DrBob222

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 ...
Wednesday, January 14, 2009 at 10:37pm by Larry

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?
Tuesday, March 23, 2010 at 10:09pm by Lee

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 ...
Monday, July 1, 2013 at 10:33am by Kris

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. !
Monday, July 26, 2010 at 12:33am by Nicole

Chemistry
I would not accept either answer although the response that pH talks about neutrality and contamination talks about purity. But the reason why H2O is neutral is that (H^+) = (OH^-) and FOR THAT REASON, the pH=7.0. You are correct that pure water is neither acidic nor alkaline ...
Sunday, October 25, 2009 at 6:20pm by DrBob222

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
Sunday, December 29, 2013 at 12:20pm by Fai

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 ...
Sunday, August 19, 2007 at 4:40am by Smiley

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
Wednesday, September 19, 2012 at 8:36pm by Lacey

physics
I wonder how much you need to prepare? I wonder what are the safey precautions with oxalic acid? Handling precaustions? storage requiremetns? labeling requirements? I wonder what purity you need? My calculator wonders what is the molecular mass of the oxalic acid you are using...
Thursday, February 24, 2011 at 8:41am by Anonymous

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?
Sunday, December 5, 2010 at 10:27pm by Cynthia

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.
Wednesday, September 8, 2010 at 7:40pm 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.
Tuesday, February 1, 2011 at 11:52pm by pho le

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.
Sunday, January 26, 2014 at 7:17am by Anonymous

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. ...
Wednesday, September 19, 2012 at 5:06pm by cheri

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 ...
Wednesday, May 12, 2010 at 9:22pm by Andy

Pages: 1 | 2 | 3 | Next>>

Search
Members