IMO Practice Test — Thermodynamics

A gas absorbs 500 J and does 200 J of work. $\Delta U$ is:

For $2\text{SO}_2+\text{O}_2\rightarrow 2\text{SO}_3$, $\Delta n_g$ is:

2 mol of an ideal gas expands isothermally and reversibly to twice its volume at 300 K. The work done by the gas is (R=8.314):

Given $\Delta_c H$: C=$-393.5$, H₂=$-285.8$, C₂H₆(combustion of ethane uses $\Delta_f$)... If $\Delta_f H(\text{CO}_2)=-393.5$ and $\Delta_f H(\text{H}_2\text{O})=-285.8$, then $\Delta_c H$ of $\text{H}_2$ is:

Estimate $\Delta H$ for $\text{CH}_4\rightarrow\text{C}+4\text{H}$ if each C–H bond is 416 kJ/mol:

For NaCl Born–Haber: if $\Delta_f H=-411$, $\Delta_{sub}=108$, ½D=121, IE=496, $\Delta_{eg}=-349$, lattice enthalpy is:

A reaction has $\Delta H=-50$ kJ, $\Delta S=-100\ \text{J/K}$. At what temperature is $\Delta G=0$?

If $\Delta G^\circ=-RT\ln K$ and $K=1$, then $\Delta G^\circ$ is:

Vaporisation of 1 mol water at 373 K with $\Delta H=40.7$ kJ gives $\Delta S$ of:

For an ideal monatomic gas $C_v=\tfrac32 R$. The ratio $\gamma=C_p/C_v$ is:

When the number of gaseous molecules increases in a reaction, $\Delta S$ is generally:

A reaction with $\Delta H>0$ and $\Delta S>0$ is spontaneous:

Heat released when 1 mol HCl forms from H–H=435, Cl–Cl=242, H–Cl=431 (per mol HCl):

At constant pressure, the heat absorbed equals: