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Chemical equilibrium — Question 4

QCAA 2023, Paper 1 · 1 mark

Q4 · 2023 · Paper 1Unclassified1 mark

QUESTIONS 4–5

Questions 4–5 refer to the decomposition of hydrogen iodide gas (HI) to produce hydrogen gas (H2) and iodine gas (I2) in a sealed 1-litre container.

Chemistry question figure

∆H = +53.6 kJ mol−1∆\mathrm{H}\,=\,+\text{53.6 kJ mol}^{-1}

2HI(g)

H2(g)

I2(g) +

Colourless

Colourless

Purple

QUESTION 4

Identify which change would shift the system from light purple to dark purple.

(A) adding HI(g)

(B) adding a catalyst

(C) decreasing the temperature

(D) increasing the concentration of H2(g)

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