Chemistry 0620 · IGCSE · Alcohols

Alcohols — practice question

This question concerns ethanol.
(a)[5]

Describe how this is carried out. Your answer should include: the equation for the reaction that forms ethanol the essential conditions for the reaction that forms ethanol the name of the process used to separate ethanol, in a pure enough form to be used as a fuel, from the reaction mixture.

(b)[3]

Using the bond energies in the table, work out the energy change, in kJ/mol, for the complete combustion of ethanol. Calculate: Energy required to break the bonds. Energy given out when bonds form. Energy change for the complete combustion of ethanol.

(c(i))[2]

What does the term catalyst mean?

(c(ii))[3]

Finish the dot-and-cross diagram to display the electron arrangement in one molecule of ethanal. Show only the outer-shell electrons.

(c(iii))[1]

Using attractive forces between particles, suggest why ethanal boils at a lower temperature than ethanol.

(d(i))[2]

State and explain how raising the pressure affects the equilibrium position. All other conditions stay the same.

(d(ii))[2]

State and explain how raising the pressure affects the reaction rate. All other conditions stay the same.

(d(iii))[2]

State and explain how increasing the temperature changes the equilibrium position. All other conditions stay the same.

Worked solution & mark scheme

This 20-mark question has a full step-by-step worked solution and mark scheme. One marking point: C6H12O6 → 2CO2 + 2C2H5OH

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