When two species of different genealogy come to resemble each other as a result of adaptation,the phenomenon is termed as

Assertion : For an isothermal reversible process $Q = -W$,i.e.,work done by the system equals the heat absorbed by the system.
Reason : Enthalpy change $(\Delta H)$ is zero for an isothermal process.

$A$ pair of perpendicular straight lines passes through the origin and also through the point of intersection of the curve $x^2+y^2=4$ with $x+y=a$. The set containing the value of $a$ is

If the roots of the equation $x^2 - 2ax + a^2 + a - 3 = 0$ are real and less than $3$,then:

Assign $A, B, C, D$ from the given type of reaction.
$PbO_2 + 4HCl \xrightarrow{\text{Warm}} PbCl_2 + Cl_2 + 2H_2O$

What are the products formed when chlorine is passed through an aqueous hypo solution?