Question

How many statements are true for photosynthesis.
(A) $C{O_2}$ is oxidized and ${H_2}O$ is reduced
(B) $C{O_2}$ is reduced and ${H_2}O$ is oxidized
(C) $C{O_2}$ is reduced to from glucose
(D) ${H_2}O$ is oxidized to evolve ${O_2}$.
A. One
B. Two
C. Three
D. Four

Answer 1

In order to solve this question we need to know about photosynthesis. We represent the process of Photosynthesis by the equation as follows-
$6C{O_2} + 6{H_2}O + light \to {C_6}{H_{12}}{O_6} + 6{O_2}$
During this process, we see two types of reactions. These are light-dependent and light-independent reactions. During these reactions, the organisms convert carbon dioxide and water into sugars and oxygen.

Complete answer:
This is true for equation (A)- $C{O_2}$ is oxidized and ${H_2}O$ is reduced.
During the process of Photosynthesis, electrons from water transfers into energy-poor $C{O_2}$ molecules, forming energy-rich sugar molecules as a result. This electron transfer that occurs during photosynthesis is an example of an oxidation-reduction process. In this water is oxidized (loses electrons) and the $C{O_2}$ is reduced (gains electrons).

Equation (B)- $C{O_2}$ is reduced and ${H_2}O$ is oxidized- is false because $C{O_2}$ is oxidized and not reduced during photosynthesis.

Equation (C)- $C{O_2}$ is reduced to from glucose- is also false because $C{O_2}$ is not reduced during photosynthesis.

Equation (D)- ${H_2}O$ is oxidized to evolve ${O_2}$ - is also false because ${H_2}O$ is reduced and not oxidized during photosynthesis.

Option B-two, option C- three, and option D- four, are incorrect because only one equation- (A) is true and others are false.

Note:
Photosynthesis is the process in which green plants and certain other organisms transform light energy into chemical energy by producing water and glucose. During photosynthesis in green plants, light energy is captured by chloroplasts. Carbon dioxide and minerals are also collected. These are converted into oxygen and energy-rich organic compounds.