Question

Glucose, on reduction with Na/Hg and water, gives:
A. Sorbitol
B. Fructose
C. Saccharic acid
D. Gluconic acid

Answer 1

Glucose or grape sugar occurs in ripe grapes, honey, and in most of the sweet fruits. It is a normal constituent of blood and is present in the urine of diabetic patients. In the combined state, it is present in sucrose, maltose, lactose, starch, and glycogen. It exists in two isomeric forms i.e. $\alpha$ and $\beta$ glucose. It is the main source of energy for the human body and helps in the movement of muscles. Its chemical formula is ${C_6}{H_{12}}{O_6}$.

Complete step by step answer:
Now we will discuss the given options one by one.
The first option is Sorbitol. Glucose on reduction with Na/Hg and water, it forms a hexahydric alcohol which is known as Sorbitol. The reaction involved in this process is written below:

${C_6}{H_{12}}{O_6} + 2H\xrightarrow{{Na/Hg}}HOC{H_2}{\left( {CHOH} \right)_4}C{H_2}OH$
$(Glucose)\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\;\ \;\;\;\;\;\;\;\;\; (Sorbitol)$

The second option is Fructose. Fructose is prepared in the same way as glucose is prepared. It is prepared in the laboratory by the hydrolysis of sucrose in presence of dilute hydrochloric acid in an alcoholic medium. A mixture of glucose and fructose is formed. The reaction involved in this process is written below:

${C_{12}}{H_{22}}{O_{11}} + {H_2}O\xrightarrow{{{H^ + }}}{C_6}{H_{12}}{O_6} + {C_6}{H_{12}}{O_6}$
$\text{(Sucrose) (Glucose) (Fructose)}$

Glucose being insoluble in alcohol separates while fructose remains in solution.

The third option is Saccharic acid. When glucose reacts with dilute $HN{O_3}$ (nitric acid), Saccharic acid is formed. The reaction involved in this process is written below:

${C_6}{H_{12}}{O_6}\xrightarrow{{dil,HN{O_3}}}HOOC{\left( {CHOH} \right)_4}COOH$
$\text{(Glucose) (Saccharic acid)}$

The fourth option is Gluconic acid. Glucose on oxidation with bromine water forms gluconic acid containing the same number of carbon atoms. The reaction involved in this process is written below:
${C_6}{H_{12}}{O_6}\xrightarrow[{[O]}]{{B{r_2}\,water}}{C_5}{H_{11}}{O_5}COOH$
$\text{(Glucose) (Gluconic acid)}$

After discussing we can conclude that glucose on reduction with Na/Hg and water gives sorbitol.

So, the correct answer is Option A .

Note: Compounds like Glucose, Fructose, Maltose, Starch, Cellulose, and Glycogen belong to a class of organic compounds known as Carbohydrates. Cellulose, in the form of cotton, linen; rayon, and cellulose acetate provide clothing for us. Cellulose in the form of wood is used for building houses and furniture. Thus, carbohydrates provide the necessity of life, food, clothing, and shelter. In green plants, these are formed as a result of photosynthesis.