Describe a reversible reaction at equilibrium by referring to: the rate of the forward reaction compared with the rate of the reverse reaction; the concentrations of reactants and products.
Fill in Table 4.1 using only increases, decreases or no change.
State what conclusion about the forward reaction can be drawn from this information.
Use the bond energies in Table 4.2 to calculate the enthalpy change, in kJ/mol, for the reaction. Follow these steps: find the total energy needed to break the bonds in $\mathrm{C}_2\mathrm{H}_4$ and $\mathrm{Cl}_2$; find the total energy released when the bonds form in $\mathrm{CH}_2\mathrm{ClCH}_2\mathrm{Cl}$; work out the reaction enthalpy change. Your answer must include a sign.
Complete the dot-and-cross diagram in Fig. 4.1 for a molecule of $\mathrm{NCl}_3$. Show only the outer shell electrons.
Give two observations that are seen when solid magnesium carbonate is added to dilute hydrochloric acid.
Calculate the volume, in cm^{3}, of $\mathrm{CO}_2(g)$ produced at room temperature and pressure (r.t.p.). Use these steps: work out the number of moles of HCl in 50.0 cm^{3} of 0.100 mol/dm^{3} HCl; deduce the number of moles of $\mathrm{CO}_2(g)$ formed; calculate the volume, in cm^{3}, of $\mathrm{CO}_2(g)$ produced at r.t.p.