Answer
Verified
428.7k+ views
Hint: To solve this question we should be aware of the composition of Tollen's Reagent and why the test is performed. The silver mirror coating of the test tube after performing the test indicates that the test is positive.
Complete step by step solution:
Tollen's reagent is an ammoniacal solution of silver oxide. It is obtained by adding ammonia to a precipitate of silver oxide present in a solution of silver nitrate and sodium hydroxide. While preparing the Tollen's reagent make sure that the reagent is well applied to sides of the test tube as this results in formation of a beautiful silver mirror if the Tollens test performed is positive.
Let me explain option wise
-Option A is glucose and sucrose. Firstly, let's draw the structure of both glucose and sucrose:
The Tollen's test gives positive results only when aldehyde and $\alpha - hydroxy$ ketone is present. Glucose contains an aldehyde group on top so glucose gives a positive test, but sucrose does not have any free aldehyde or $\alpha - hydroxy$ ketone. Therefore, option A is the wrong answer.
-Option B is Glucose and fructose. Let's draw the structure of both glucose and fructose:
Glucose contains an aldehyde group and fructose contains a $\alpha - hydroxy$ ketone. Tollen's test gives positive results only when aldehyde and $\alpha - hydroxy$ ketone is present. The Tollen's reagent oxidises the aldehyde or $\alpha - hydroxy$ ketone and the silver ions is reduced to metallic forms which get deposited on the sides of the test tube. Therefore option B is the correct answer.
-Option C is hexanal and acetophenone. The hexanal and acetophenone are aldehydes and ketones respectively. Only aldehyde answers for the test, but acetophenone won't answer. Hence option C is wrong.
-Option D is Fructose and sucrose. Let's draw the structure of both fructose and sucrose.
As we saw earlier, fructose will show positive test and sucrose won't show positive test.
Therefore, option D is the wrong option answer.
Thus, option B is the correct answer.
Note: When aldehyde and $\alpha - hydroxy$ ketone is present. Tollen's reagent oxidises the aldehyde or $\alpha - hydroxy$ ketone and the silver ions is reduced to metallic forms which get deposited on the sides of the test tube.
Complete step by step solution:
Tollen's reagent is an ammoniacal solution of silver oxide. It is obtained by adding ammonia to a precipitate of silver oxide present in a solution of silver nitrate and sodium hydroxide. While preparing the Tollen's reagent make sure that the reagent is well applied to sides of the test tube as this results in formation of a beautiful silver mirror if the Tollens test performed is positive.
Let me explain option wise
-Option A is glucose and sucrose. Firstly, let's draw the structure of both glucose and sucrose:
The Tollen's test gives positive results only when aldehyde and $\alpha - hydroxy$ ketone is present. Glucose contains an aldehyde group on top so glucose gives a positive test, but sucrose does not have any free aldehyde or $\alpha - hydroxy$ ketone. Therefore, option A is the wrong answer.
-Option B is Glucose and fructose. Let's draw the structure of both glucose and fructose:
Glucose contains an aldehyde group and fructose contains a $\alpha - hydroxy$ ketone. Tollen's test gives positive results only when aldehyde and $\alpha - hydroxy$ ketone is present. The Tollen's reagent oxidises the aldehyde or $\alpha - hydroxy$ ketone and the silver ions is reduced to metallic forms which get deposited on the sides of the test tube. Therefore option B is the correct answer.
-Option C is hexanal and acetophenone. The hexanal and acetophenone are aldehydes and ketones respectively. Only aldehyde answers for the test, but acetophenone won't answer. Hence option C is wrong.
-Option D is Fructose and sucrose. Let's draw the structure of both fructose and sucrose.
As we saw earlier, fructose will show positive test and sucrose won't show positive test.
Therefore, option D is the wrong option answer.
Thus, option B is the correct answer.
Note: When aldehyde and $\alpha - hydroxy$ ketone is present. Tollen's reagent oxidises the aldehyde or $\alpha - hydroxy$ ketone and the silver ions is reduced to metallic forms which get deposited on the sides of the test tube.
Recently Updated Pages
How many sigma and pi bonds are present in HCequiv class 11 chemistry CBSE
Mark and label the given geoinformation on the outline class 11 social science CBSE
When people say No pun intended what does that mea class 8 english CBSE
Name the states which share their boundary with Indias class 9 social science CBSE
Give an account of the Northern Plains of India class 9 social science CBSE
Change the following sentences into negative and interrogative class 10 english CBSE
Trending doubts
What is the use of keeping food in air tight conta class 10 chemistry CBSE
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
The SI unit of potential difference is a Ohm b Ampere class 11 physics CBSE
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
Differentiate between homogeneous and heterogeneous class 12 chemistry CBSE
An electric lamp of the resistance 20 and a conductor class 12 physics CBSE
Draw a diagram of nephron and explain its structur class 11 biology CBSE
In the touchmenot plant the leaves show movements What class 11 biology CBSE
Which are the Top 10 Largest Countries of the World?