Calculate the surface temperature of the planet,if the energy radiated by unit area in unit time is $5.67 \times 10^4 \, W$. (Assume the planet is a black body).

An electrochemical cell is fueled by the combustion of butane at $1$ bar and $298 K$ . Its cell potential is $\frac{ X }{ F } \times 10^3$ volts, where $F$ is the Faraday constant. The value of $X$ is $...$ .
Use : Standard Gibbs energies of formation at $298 K$ are : $\Delta_f G_{ CO _2}^{ o }=-394 kJ mol ^{-1}; \Delta_f G_{\text {water }}^{ o }=-237 kJ mol ^{-1} ; \Delta_f G_{\text {butane }}^{ o }=-18 kJ mol ^{-1}$

The partial pressure of oxygen in the alveoli of the lungs is

Which of the following is a $\pi$-acid ligand?

In a triangle,if $r_1 = 2r_2 = 3r_3$,then $\frac{a}{b} + \frac{b}{c} + \frac{c}{a}$ is equal to

In which of the following is the notochord present in the embryonic stage?