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Question bank

Original exam-style questions, mapped to your syllabus. Answers are checked for mathematical equivalence and every attempt updates your mastery.

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12 questions

SA-AC-RD-0011 markL1 FoundationCalculatorOxidation numbers
What is the oxidation number of Cr in Cr2O72−\mathrm{Cr_2O_7^{2-}}?

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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0121 markL1 FoundationCalculatorOxidation numbers
Oxidation is an
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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0021 markL2 StandardCalculatorOxidation numbers
What is the oxidation number of S in S2O32−\mathrm{S_2O_3^{2-}}?

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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0031 markL2 StandardCalculatorHalf-equations
How many electrons are in the half-equation MnO4−+8H++_ e−→Mn2++4H2O\mathrm{MnO_4^-+8H^++\_\,e^-\rightarrow Mn^{2+}+4H_2O}?

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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0041 markL2 StandardCalculatorHalf-equations
How many H⁺ are needed in Cr2O72−+_ H++6e−→2Cr3++7H2O\mathrm{Cr_2O_7^{2-}+\_\,H^++6e^-\rightarrow2Cr^{3+}+7H_2O}?

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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0051 markL2 StandardCalculatorOxidation numbers
In Cl2+2OH−→Cl−+ClO−+H2O\mathrm{Cl_2+2OH^-\rightarrow Cl^-+ClO^-+H_2O}, chlorine is
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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0063 marksL2 StandardCalculatorRedox titrations
25.0 cm325.0\ \text{cm}^3 of Fe²⁺ solution reacts with 22.50 cm322.50\ \text{cm}^3 of 0.02000.0200 mol dm⁻³ KMnO4\mathrm{KMnO_4}. Calculate c(Fe2+)c(\mathrm{Fe^{2+}}).

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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0081 markL2 StandardCalculatorRedox titrations
In a manganate(VII) titration, no indicator is needed because
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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0091 markL2 StandardCalculatorRedox titrations
In an iodine–thiosulfate titration, starch is added near the end point and the colour changes from
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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0101 markL2 StandardCalculatorOxidation numbers
In NaH\mathrm{NaH}, the oxidation number of hydrogen is
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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0073 marksL3 ExamCalculatorRedox titrations
Iodine released in a reaction needs 18.0 cm318.0\ \text{cm}^3 of 0.1000.100 mol dm⁻³ Na2S2O3\mathrm{Na_2S_2O_3}. How many moles of I₂ were present? (I2+2S2O32−→2I−+S4O62−\mathrm{I_2+2S_2O_3^{2-}\rightarrow2I^-+S_4O_6^{2-}})

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Salam Academy Original Practice · Proposed mark scheme
SA-AC-RD-0112 marksL3 ExamCalculatorHalf-equations
Combine Cr2O72−+14H++6e−→2Cr3++7H2O\mathrm{Cr_2O_7^{2-}+14H^++6e^-\rightarrow2Cr^{3+}+7H_2O} with Fe2+→Fe3++e−\mathrm{Fe^{2+}\rightarrow Fe^{3+}+e^-}. How many Fe²⁺ react per Cr2O72−\mathrm{Cr_2O_7^{2-}}?

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Salam Academy Original Practice · Proposed mark scheme