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Which sugar gives a negative reaction to Benedict reagent?
AbdihakinHassan
Benedict's reagent is a type of chemical that is used to test if reducing sugars are present or not. The chem'ical is named after Stanley Rossiter Benedict.
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What is the chemical equation for the reaction between glucose and Benedict's reagent?
.H-C=O + 4OH- + 2Cu2+ --> HO-C=O + Cu2O(s) + 2H2O.H-C-OH....................................H-C-OHHOC-H ....................................HOC-H.H-C-OH....................................H-C-OH.H-C-OH....................................H-C-OHH2C-OH....................................H2C-OH[Dots were used ..... to fill up spaces because repeating space bar will not work as space holder for vertical Fischer projection][Benedict's reagent will work out as Cu2+ in hydroxidic (OH-) solution]
Why is the enthalpy change of combustion always negative?
It is and exothermic reaction, which means energy is given out heating the surroundings.
Why sucrose does not give a positive Benedict's test but hydrolyzed sucrose does give a positive beneditcts test?
Sucrose is formed from glucose and fructose.Sucrose is formed from glucose and fructose. Glucose and fructose gives positive test for benedict becuz both of them are reducing sugars whereas sucrose is not a reducing sugar so it gives negative test for benedict. On prolonged heating,sucrose will form glucose and fructose (reducing sugars)which ultimately gives a positive result .
Does Bayer's Reagent gives glycol with 2-methyl-propene?
Yes Bayers reagent is Alkaline and it gives syn addition of two -OH groups across the double bond but if acidified KMnO4 is taken then that will cleave the double bond and give a mixture of acids
What term is used for the type of chemical reaction that gives out heat energy?
Exothermic reaction gives free heat (energy).
Is Pararosaniline is schiff's reagent?
No, its reaction with SO2(aq) gives schiff's reagent.
A reducing sugar gives a precipitate of silver metal with Benedict's reagent.?
This is probable an error.
Is fructose gives positive test with tollens reagent?
no negative
What is the difference between Benedict's Reagent and Biuret Reagent?
Benedicts reagent is used to check reducing sugars , it need hat to work and gives red color when positive ,. While biuret reagent is for proteins .there is no need to use heat and gives purple , violet color when positive ..
Sugar in blood and urine is tested with which solution?
Sugar in blood and urine is tested with Benedict's solution.
What is the chemical equation for the reaction between glucose and Benedict's reagent?
.H-C=O + 4OH- + 2Cu2+ --> HO-C=O + Cu2O(s) + 2H2O.H-C-OH....................................H-C-OHHOC-H ....................................HOC-H.H-C-OH....................................H-C-OH.H-C-OH....................................H-C-OHH2C-OH....................................H2C-OH[Dots were used ..... to fill up spaces because repeating space bar will not work as space holder for vertical Fischer projection][Benedict's reagent will work out as Cu2+ in hydroxidic (OH-) solution]
What is Benedict test for?
You must take the testing object, then add Benedict's solution in a test tube. Then in a boiling beaker of water, place the test tube in. Let it sit there and see if there is any color change or precipitated materials.
When does a spray of diphenylamine reagent on TLC gives blue coloration?
Diphenylamine is a reagent for DNA.
Why is the enthalpy change of combustion always negative?
It is and exothermic reaction, which means energy is given out heating the surroundings.
Why sucrose does not give a positive Benedict's test but hydrolyzed sucrose does give a positive beneditcts test?
Sucrose is formed from glucose and fructose.Sucrose is formed from glucose and fructose. Glucose and fructose gives positive test for benedict becuz both of them are reducing sugars whereas sucrose is not a reducing sugar so it gives negative test for benedict. On prolonged heating,sucrose will form glucose and fructose (reducing sugars)which ultimately gives a positive result .
Why ether is used instead of water in Grignards reagent?
it is used because it gives power
What is benidicks solution?
Benedict's reagent is used as a test for the presence of reducing sugars.It is often used in place of Fehling's solution.This includes all monosaccharides and the disaccharides lactose and maltose.Even more generally, Benedict's test will detect the presence of aldehydes and alpha-hydroxy-ketones, including those that occur in certain ketoses. Thus, although fructose is not strictly a reducing sugar, it is an alpha-hydroxy-ketone, and gives a positive test because it is converted into the aldoses glucose and/or mannose by the base (carbonate) in the reagent.One litre of Benedict's reagent can be prepared from 100 g of anhydrous sodium carbonate, 173 g of sodium citrate and 17.3 g of copper(II) sulfate pentahydrate.Benedict's reagent contains blue copper(II) ions (Cu2+) which are reduced to copper(I) (Cu+). These are precipitated as red copper(I) oxide (Cu2O) which is insoluble in water.
