Oxidation and Reduction
Chemistry ⇒ Redox Reactions and Electrochemistry
Oxidation and Reduction starts at 10 and continues till grade 12.
QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Oxidation and Reduction.
How you perform is determined by your score and the time you take.
When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.
See sample questions for grade 11
Assign the oxidation number to nitrogen in NO3-.
Assign the oxidation number to phosphorus in H3PO4.
Calculate the oxidation number of chromium in K2Cr2O7.
Describe the steps to assign oxidation numbers to atoms in a polyatomic ion.
Calculate the change in oxidation number of manganese in the reaction: 2MnO4- + 5C2O42- + 16H+ → 2Mn2+ + 10CO2 + 8H2O
Explain why the reaction between hydrogen and oxygen to form water is a redox reaction.
Fill in the blank: In the reaction 2Na + Cl2 → 2NaCl, sodium is __________ (oxidized/reduced).
Fill in the blank: In the reaction Fe2+ → Fe3+ + e-, Fe2+ is __________ (oxidized/reduced).
Which of the following elements has an oxidation state of zero in its elemental form? (1) O2 (2) H2O (3) NaCl (4) CO2
Which of the following is a redox reaction? (1) CaCO3 → CaO + CO2 (2) 2K + Br2 → 2KBr (3) AgNO3 + NaCl → AgCl + NaNO3 (4) H2SO4 + NaOH → Na2SO4 + H2O
Which of the following is NOT a redox reaction? (1) 2H2 + O2 → 2H2O (2) NaCl + AgNO3 → AgCl + NaNO3 (3) Fe + CuSO4 → FeSO4 + Cu (4) 2Na + Cl2 → 2NaCl
Which of the following is the correct definition of reduction? (1) Gain of electrons (2) Loss of electrons (3) Gain of oxygen (4) Loss of hydrogen
Fill in the blank: In the reaction 2Na + Cl2 → 2NaCl, sodium is __________ (oxidized/reduced).
Fill in the blank: In the reaction Fe2+ → Fe3+ + e-, Fe2+ is __________ (oxidized/reduced).
Fill in the blank: The gain of oxygen by a substance is called __________.
Fill in the blank: The loss of hydrogen from a substance is also considered as __________.
True or False: In a redox reaction, the oxidizing agent is always reduced.
True or False: In a redox reaction, the substance that is reduced acts as the oxidizing agent.
True or False: Oxidation and reduction always occur simultaneously in a chemical reaction.
True or False: The oxidation number of oxygen is always -2 in all compounds.
