For the reaction sequence given below, the correct statement$(s)$ is$(are)$
image
$(A) \ P$ is optically active.
$(B) \ S$ gives Bayer's test.
$(C) \ Q$ gives effervescence with aq. $NaHCO _3$.
$(D) \ R$ is an alkyne.

$3$ moles of an ideal monoatomic gas perform an $A B C D A$ cyclic process as shown in the figure. The gas temperatures are $T_A=400 \, K$, $T_B=800 \, K$, $T_C=2400 \, K$, and $T_D=1200 \, K$. The work done by the gas is (approximately) $(R=8.314 \, J / mol K)$. (in $ \, kJ$)

Which of the following has the lowest melting point?

Two plants can be conclusively said to belong to the same species if they

The $Ka$ of $H_2O_2$ is of the order of:

Which fungi obtain their nutrition from decaying organic matter?