The synthesis of alkyl fluorides is best accomplished by:

Two rods of different materials having coefficients of linear expansion $\alpha_1$ and $\alpha_2$ and Young's moduli $Y_1$ and $Y_2$ respectively are fixed between two rigid massive walls. The rods are heated such that they undergo the same increase in temperature. There is no bending of rods. If $\alpha_1 : \alpha_2 = 2 : 3$,the thermal stress developed in the two rods is equal provided $Y_1 : Y_2$ is equal to:

Two rain drops reach the earth with different terminal velocities having ratio $9:4$. Then the ratio of their volumes is

How many moles of $KMnO_4$ are required to oxidize $1 \ mol$ of $FeC_2O_4$ in an acidic medium?

Define the octet rule. Write its significance and limitations.

Which of the following statements is correct for any thermodynamic system?