Calculate the work done in the following reaction at $$300 \mathrm{~K}$$ and at constant pressure.

$$\left(\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}\right)$$

$$4 \mathrm{HCl}_{(\mathrm{g})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow 2 \mathrm{Cl}_{2(\mathrm{~g})}+2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{g})}$$

The solubility product of $$\mathrm{Mg}(\mathrm{OH})_2$$ is $$1.8 \times 10^{-11}$$ at $$298 \mathrm{~K}$$. What is its solubility in $$\mathrm{mol} \mathrm{~dm}^{-3}$$ ?

If $$\mathrm{K}_{\mathrm{sp}}$$ is solubility product of $$\mathrm{Al}(\mathrm{OH})_3$$, its solubility is expressed by formula,

Which from following is the slope of the graph of $$[\mathrm{A}]_{\mathrm{t}}$$ versus time for zero order reaction?