25 cm of liquid 'A' and 20 cm of liquid 'B' are mixed at 25°C and the volume of
solution was measured to be 44.8 cm3
then correct reaction is
(A) A Hmix = 0, solution shows
ideal

The correct option is;

(B) , solution shows negative deviation

Explanation:

The given parameters are;

The available volume of liquid A = 25 cm³

The available volume of liquid B = 20 cm³

The volume of the solution (mixture) = 44.8 cm³

Therefore, we have;

Which is one of the prerequisite for the formation of negative deviation

When a non-ideal solution shows negative deviation according to Raoult's Law, we have;

, we have more heat released due to new molecular interactions.

is there multiple choice answers?

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.