1000 Questions Bond Breaking Bond Making

Bond Breaking Bond Making

Question 1

Methanol can be prepared via the reaction of methane with oxygen, as seen in the following equation:

$2CH_{4(g)}+O_{2(g)}\rightarrow 2CH_3OH_{(g)}$

i) Use the bond energies given to calculate the energy change for this reaction.

ii) Draw an energy level diagram for this reaction

Question 2

Nitrogen does not easily react with oxygen, though this can happen during thunderstorms. The reaction that takes place is the following:

$N_{2(g)}+O_{2(g)}\rightarrow 2NO_{(g)}$

Using bond energies, explain why this reaction does not keep going after initiation.

Question 3

Hydrogen peroxide slowly decomposes into water and oxygen:

$H_2O_{2(l)}\rightarrow H_2O_{(g)}+O_{(2)}$

Use the bond energies to calculate the energy change for this reaction.

Question 4

Bromine adds to ethene via an electrophilic addition:

$C_2H_{4(g)}+Br_{2(l)}\rightarrow CH_2BrCH_2Br_{(l)}$

Use the bond dissociation energies to calculate the enthalpy change for this reaction.

Question 5

When using values from Table ### the enthalpy change for the hydrogenation of ethene, but-1-ene and trans-but-2-ene are the same. Explain why the true values for such hydrogenations are -32.8, -30.3 and -27.6 kJ mol^-1 respectively.