Calculate enthalpy change for following reaction.

$$\mathrm{H}_2 \mathrm{C}=\mathrm{CH}_{2(\mathrm{~g})}+\mathrm{H}_{2(\mathrm{~g})} \longrightarrow \mathrm{H}_3 \mathrm{C}-\mathrm{CH}_{3(\mathrm{~g})}$$

[The bond energy of $\mathrm{C}-\mathrm{H}, \mathrm{C}-\mathrm{C}, \mathrm{C}=\mathrm{C}$ and $\mathrm{H}-\mathrm{H}$ is $414,347,615$ and 435 kJ respectively]

Which among the following is NOT an intensive property?

In a process 605 J heat is absorbed by the system and 380 J work is done by the system on surrounding. What is the value of $\Delta$U?

A gas absorbs certain amount of heat and expands by $200 \mathrm{~cm}^3$ against a constant external pressure of $2 \times 10^5 \mathrm{Nm}^{-2}$. What is work done by system?