QCEVault

Chemical equilibrium — Question 31

Original QCE Vault practice · 4 marks

Q31 · Practice questionSimple familiar4 marks

QUESTION 31 (4 marks)

A small sealed display vial contains brown NO2 and colourless N2O4: N2O4(g)⇌2NO2(g). The brown colour deepens when the vial is warmed.

a) Determine whether the forward reaction is endothermic or exothermic. Justify your answer. [2 marks]

b) Explain why the colour becomes constant after the warmed vial is held at a fixed temperature. [2 marks]

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