# Purity

175 results

### 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?

### 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) %

### 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?

### 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...

### 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 ...

### 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...

### chemistry

how do i prepare a sulphuric acid solution having 75 % purity with 1.68 specific gravity from sulphuric acid with 97 % purity and 1.834 specific gravity.

### 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...

### 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)

### 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 ...

### 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 ...

### chemistry

how can the purity of water be established?

### science

how do u find out the purity of sand

### 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+ --> ...

### Scince

How do you think you could increase the purity of the nitrogen gas?

### chemistry

can fractional distillation be used to determine purity of a compound?

### chemistry

prepare 500mM 100 ML HCL (37% purity, density 1.8)

### biology

How do I calculate protein concentration if I know the purity is 97.3% and MW = 2666.31 kDA Thanks

### biology

How do I calculate protein concentration if I know the purity is 97.3% and MW = 2666.31 kDA Thanks

### Chemistry

What mass of CaO, can get by the decomposition of 250 g of CaCo3 with 80% purity?

### Chemistry

How can I make 100ml 0f 2N of HCl? purity is 35% and density is given as 1.18 g/mL

### plz correct this line ..eng

but his purity is not last long as he start growing

### pharmacy

suggest a technique , other than tlc, to confirm the purity of the samples

### Biochemical methods

Expain the preparation of 250ml of 2.5% v/v H3PO4 (MW=98.0,density=1.71,%purity=85%

### o-chem

explain how the rate of crystal growth can affect the purity of a recrystallized compound

### o-chem

explain how the rate of crystal growth can affect the purity of a recrystallized compound

### Organic Chemistry

What advantages does H NMR have over melting point in the determination of purity?

### 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 ...

### Chemistry

Can anyone please tell me what can you say about the purity of the compound extracted based on your TLC results? Thanks

### Chemistry 110

4. The electrical conductivity of deionized water is commonly used as an index of its purity. Explain.

### chemistry

What is the percentage purity of sample if 3.92g of mohr's salt react completely with 50 ml N/10 Kmno4 solution

### chemistry

what weight of na2c03 of 95% purity would be required to neutralize 45.6ml of 0.235N acid? Who Helps

### Sociology

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

### 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

### Chemistry

How much amount of CaCO3 in gm having % purity 50 percent produces 0.56 litre of CO2 at STP on heating. (Answer 5)

### 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

### 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 ...

### 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

### 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...

### 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...

### Chemistry

On calcination 80g of a marble were obtained 42 g of calcium oxide. The degree of purity of marble?

### 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-...

### chemistry

50% purity NAOH liquid . if the density is 1.53 . so one liter hou much NAOH is here ?

### Chemistry

why the yield of ester is relatively low? suggest modifications which would improve the purity of ester?

### 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

### 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?

### 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

### 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

### 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

### science

20ml solution containing 0.2g of an impure sample of h2o2 reacts with 0.316g of kmno4 in the presence of h2so4. Find the purity of h2o2 in the mixture.

### 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?

### 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?

### 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?

### 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

### Chemistry

Prepare M/20 oxalic acid solution.Using this solution, find molarity, strength, and percentage purity of the sodium hydroxide solution.

### 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

### 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.

### 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?

### 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

### 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...

### 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%

### Chemistry

Make NaCl from NaHCO3 and HCl-Starting with 3.0 grams of NaHCO3-what would be a source of error on yield of purity of NaCl and what modifications could be made?

### 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.

### chemistry

Explain why the yield of ester is relatively low? How to improve the yield and the purity of ester?

### Chemistry

Dissolved 0.7500 g calcium chloride dihydrate and impure, in distilled water and the volume was elevated to 200.00 mL in a volumetric flask. A rate of 10.00 mL of the same consumed the titration 18.9 mL 0.0125 M EDTA using CALCON as indicator. What is the purity of the salt...

### Chemistry

Dissolved 0.7500 g calcium chloride dihydrate and impure, in distilled water and the volume was elevated to 200.00 mL in a volumetric flask. A rate of 10.00 mL of the same consumed the titration 18.9 mL 0.0125 M EDTA using CALCON as indicator. What is the purity of the salt...

### Chemistry

Dissolved 0.7500 g calcium chloride dihydrate and impure, in distilled water and the volume was elevated to 200.00 mL in a volumetric flask. A rate of 10.00 mL of the same consumed the titration 18.9 mL 0.0125 M EDTA using CALCON as indicator. What is the purity of the salt...

### 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

### 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?

### 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.

### 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.

### 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...

### 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 ...

### Chemistry

Dissolved 0.7500 g calcium chloride dihydrate and impure, in distilled water and the volume was elevated to 200.00 mL in a volumetric flask. A rate of 10.00 mL of the same consumed the titration 18.9 mL 0.0125 M EDTA using CALCON as indicator. What is the purity of the salt...

### 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

### 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?

### 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.

### chemistry

An impure silver sample weighing 0.1652g reacts with diluted HNO3, forming the add HCl, a white precipitate that weighed 0.0911 g of silver chloride. What degree of purity of silver in the sample?

### Chemistry

1.025g of an impure sample of a weak acid HX(mol mass = 82) is dissolved in 60ml of water and titrated with 0.25M NaOH. When half of the acid was neutralized the pH was found to be 5.0 and at the equivalence point the pH is 9.0. Find the % purity of this sample of HX Pls help ...

### 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 .

### Chem Help Please!

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.

### 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?

### 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...

### 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

### 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

### 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. !

### chemistry

a 500ml stock solution of NAOH has a purity of 70% and a density of 1.9g/ml. calculate the concentration that would be in a 1L solution. calculate the molarity. What volume would we have to take to prepare 250ml of a solution of 0.1 mol/l

### chemistry

3. A carbonate fusion was needed to free the Bi from a 0.6423-g sample of eulytite (2Bi2O3·3SiO2). The fused mass was dissolved in dilute acid, following which the Bi+3 was titrated with 27.36mL of 0.03369M NaH2PO4. The reaction is Bi+3 + H2PO4-  BiPO4(s) + 2H+. Calculate ...

### 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 ...

### 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...

### 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

### 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?

### 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)

### 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 ...

### 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 ...

### 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.

### 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.

### 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

### AP Chemistry

14 carat gold has a purity of 58.3%. How many moles of gold are in 138 grams of 14 carat gold? Answer in units of moles.

### Chemistry

sample of silver metal is suspected to be contaminated with zinc. A 0.2365 g portion of this metal is dissolved in nitric acid and the silver ions precipitated with excess aqueous NaCl. After filtering and drying, the mass of the precipitate is found to be 0.2865 g. What was ...

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