If the volume of $$15.9 \mathrm{~g}$$ of carbon tetrachloride is $$10 \mathrm{~mL}$$, calculate its density.

$$0.63 \mathrm{~g}$$ of oxalic acid is dissolved in order to obtain $$250 \mathrm{~cm}^3$$ of its solution. Find the normality of this solution. [oxalic acid $$\left.(\mathrm{COOH})_2 \cdot 2 \mathrm{H}_2 \mathrm{O}\right]$$

When an ideal gas expands isothermally from $$5 \mathrm{~m}^3$$ to $$10 \mathrm{~m}^3$$ at $$25^{\circ} \mathrm{C}$$ against a constant pressure of $$10^7 \mathrm{~Nm}^{-2}$$, then the work done on the gas is

Find the approximate value of $$(\Delta H-\Delta U)$$ in $$\mathrm{Jmol}^{-1}$$, for the formation of CO from its elements at $$298 \mathrm{~K} .\left(R=8.314 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\right)$$