QCEVault

Chemical synthesis — Question 8

QCAA 2021, Paper 1 · 1 mark

Q8 · 2021 · Paper 1Unclassified1 mark

QUESTION 8

Official solution diagram
Fuel inH2Excess fuel
H+H+e–e–e–
Chemistry question figure

Anode

Identify the operating conditions for the hydrogen fuel cell.

(A) acidic conditions with hydrogen given off as an unused gas

(B) alkaline conditions with hydrogen given off as an unused gas

(C) acidic conditions with hydrogen ions present in the electrolyte

(D) alkaline conditions with hydrogen ions present in the electrolyte

Question linkQCAA assessment resources

Related questions

  1. Q11 · 2025 QCAA · Paper 1 · 1 mark
    QUESTION 11 Yeasts are used in the production of ethanol by fermentation to (A) increase the rate of the reaction. (B) act as a reactant in the overall reaction. (C) increase the yield of ethanol and ensure its purity. (D) produce green ethanol by preventing the production of carbon dioxide.
    Chemical synthesis
  2. Q26 · 2025 QCAA · Paper 1 · 3 marks
    QUESTION 26  (3 marks) One step of the contact process involves reacting sulfur dioxide (SO2) and oxygen (O2) to produce sulfur trioxide (SO3), as shown. 2SO2(g) + O2(g)  2SO3(g) The equilibrium constant (Kc) for the forward reaction is 5.6 × 104 at 350 °C and 9.2 × 101 at 800 °C. a) Determine whether the forward reaction is exothermic or endothermic. [1…
    Chemical synthesis
  3. Q29 · 2025 QCAA · Paper 1 · 6 marks
    QUESTION 29  (6 marks) The oxidation of meso-hydrobenzoin (C14H14O2) to produce benzaldehyde (C7H6O) was carried out via three different reaction pathways to evaluate atom economy and E-factor. Atom economy is a measure of reaction efficiency based on the percentage of the total mass of reactants successfully converted to the desired product. E-factor is a m…
    Chemical synthesis
  4. Q7 · 2025 QCAA · Paper 2 · 4 marks
    QUESTION 7  (4 marks) Contrast the operation of a hydrogen fuel cell under acidic conditions and a hydrogen fuel cell under alkaline conditions by completing the table. Hydrogen fuel cell Contrast Acidic conditions Alkaline conditions Electrolyte used Movement of ions Note: If you make a mistake, cancel it by ruling a single diagonal line through your work a…
    Chemical synthesis