Which of the following is a component of baking powder?

Acid hydrolysis of $X$ yields two different organic compounds. Which one of the following is $X$?

Which of the following pairs of orbitals possess two nodal planes?

The mean of four observations is $3$. If the sum of the squares of these observations is $48$,then their standard deviation is

Which artery is absent in a frog?

$A$ vessel contains $110\,g$ of water. The heat capacity of the vessel is equivalent to $10\,g$ of water. The initial temperature of the water in the vessel is $10\,^{\circ}C$. If $220\,g$ of hot water at $70\,^{\circ}C$ is poured into the vessel,the final temperature,neglecting radiation loss,will be ........ $^{\circ}C$.