Which of the following is not a peroxy acid?

Which of the following reagents can form a hydrazone with alkanone?

In any $\triangle ABC$,$a(b \cos C - c \cos B)$ equals

$A$ centigrade and a Fahrenheit thermometer are dipped in boiling water. The temperature is lowered until the Fahrenheit thermometer registers $140^{\circ}F$. What is the fall in temperature in $^{\circ}C$ as registered by the centigrade thermometer?

Which proteinaceous pigment controls light-dependent activities in plants?

Suppose $A$ and $B$ are two points on the line $2x-y+3=0$ and $P(1,2)$ is a point such that $PA=PB$. Then,the mid-point of $AB$ is