Redox and acids

Question 1

Definition of oxidation

Answer 1

Loss of electrons and an increase in the oxidation of number.

Question 2

Definition of reduction

Answer 2

The gain of electrons and a decrease in oxidation number.

Question 3

Definition of redox reactions

Answer 3

Reactions in which both oxidation and reduction take place.

Question 4

Definition of an oxidising agent

Answer 4

A reagent that oxidises another species (itself is reduced).
Examples: MnO4^- / CrO7^2- / O2 / H2O2

Question 5

Definition of reducing agent

Answer 5

A reagent that reduces another species (itself is oxidised).
Examples: H2 / Na / Zn / NaBH4

Question 6

When answering exam qus about redox equations…

Answer 6

X has changed from 0 in ….. –> +3 in ….. An increase in oxidation, so oxidation.
Y has changed from +3 in ….. –> 0 in ….. A decrease in oxidation number, so reduction.

Question 7

Definition of acid

Answer 7

Proton donors

Question 8

Definition of a strong acid

Answer 8

Fully disassociates in aqueous solutions (into its ions).

Question 9

Definition of a weak acid

Answer 9

Only partially disassociates in aqueous solution.

Question 10

Definition of a base

Answer 10

Proton acceptor

Question 11

Defintion of an alkali

Answer 11

A type of base that dissolves in water forming OH- ions.

Question 12

Definition of a salt

Answer 12

A chenical compound formed when a hydrogen ion from an acid has been replaced by a metal ion or another positive ion, for example: NH4^+.

Question 13

Acid + base…

Answer 13

…salt + water

Question 14

Acid + alkali…

Answer 14

…salt + water

Question 15

Acid + metal…

Answer 15

…salt + H2

Question 16

Acid + carbonate…

Answer 16

…salt + water