Chemistry: Redox Reactions

What is the oxidation number of an atom in a chemical compound or in a polyatomic ion?

The theoretical ion charge of the atom.

What is the fundamental property of redox reactions?

One participant will be oxidised and another participant will be reduced by the transfer of one or more electrons.

What happens when a particle is reduced?

Its oxidation number decreases.

What is the sum of a reduction reaction and an oxidation reaction?

A redox reaction. Signup and view all the answers

Why are Roman numbers used for oxidation numbers?

To avoid confusion with charges of ions. Signup and view all the answers

What is the oxidation number of Fe2+ in the reaction Fe3+ + e- → Fe2+?

+II Signup and view all the answers

What happens to the oxidation number of a particle when it is oxidised?

The oxidation number increases. Signup and view all the answers

What is the function of an oxidising partner in a redox reaction?

To be reduced Signup and view all the answers

What is the definition of a reduction in a chemical reaction?

The reception of one or more electrons by a reactant. Signup and view all the answers

What is the oxidation number (ON) of oxygen in a compound?

-II Signup and view all the answers

How are chemical names written to include the oxidation number of the cation?

In roman numbers in round brackets. Signup and view all the answers

What is the minimum requirement for a reaction to be considered a redox reaction?

Transfer of one or more electrons Signup and view all the answers

What is the oxidation number of single atomic particles with no charge and elements?

Zero (±0). Signup and view all the answers

What is the sum of oxidation numbers of all atoms in a molecule without a charge?

Always ±0. Signup and view all the answers

What is the oxidation number (ON) of an element?

±0 Signup and view all the answers

What happens to the oxidation number (ON) of M in the reaction M + O2 → MO?

Increases by 2 Signup and view all the answers

What happens to the oxidation number of a reactant when it releases one or more electrons?

The reactant gets oxidised. Signup and view all the answers

Which of the redox pairs has the highest redox potential?

Ag+/Ag Signup and view all the answers

What is the purpose of adding NH3 (c = 2 mol/L) to the solution in the experiment?

To observe the reaction and identify the product Signup and view all the answers

What is the oxidising agent in the reaction between copper and nitric acid?

Nitric acid (HNO3) Signup and view all the answers

What is the purpose of using deionised water in the experiment?

To dilute the concentrated nitric acid and prevent overheating Signup and view all the answers

What is the role of the gas collecting device in Experiment 4.2?

To collect and identify the gas produced during the reaction Signup and view all the answers

Why is it important to wear gloves and eye protection during the experiment?

To prevent injury from chemicals and heat Signup and view all the answers

What is the difference in the reaction between aluminium and hydrochloric acid versus nitric acid?

The products and reaction rates differ between the two acids Signup and view all the answers

What is the purpose of the gas collecting device in the experiment?

To identify the produced gas. Signup and view all the answers

Why does the reaction of HCl with Aluminium need a significant amount of time to speed up?

Because the Aluminium surface is initially covered with a passivating compound that slows down the reaction. Signup and view all the answers

Why do we not see a reaction happen between Aluminium and HNO3?

Because the passivating compound on the Aluminium surface completely blocks the reaction with HNO3. Signup and view all the answers

What gas is produced according to the test with the gas collecting device?

The answer will depend on the actual experiment and observation, but typically it is hydrogen gas. Signup and view all the answers

What is the purpose of writing the reaction equation of the formation of the compound on the surface of Aluminium?

To understand the process that slows down the reaction with HCl and blocks the reaction with HNO3. Signup and view all the answers

Is the reaction between HCl and Aluminium a redox reaction?

Yes, it is a redox reaction. Signup and view all the answers