F321: Redox, Acids/Alkali/Salts

Question 0

Acid

Answer 0

Proton donor
(aq solution releases H+ ions)

Question 1

Redox exam English example

Answer 1

Each X has been oxidised as it’s oxidation number has increased from +2 in XO to +4 to XO2

Question 2

Base

Answer 2

Proton accepton

Question 3

Chloric acid formula and compound counter ion

Answer 3

HClO (chloric(I) acid)

ClO- (chlorate(I))

Question 4

Alkali

Answer 4

A soluble base that releases OH- in an aqueous solution

Question 5

Acid + alkali ->

Answer 5

Salt + water

Observation: none

Question 6

Acid + metal ->

Answer 6

Salt + metal

Observation: fizzing, metal disappears

Question 7

Acid + carbonate ->

Answer 7

Salt + water + carbon dioxide

Observation: fizzing, carbonate disappears

Question 8

Acid + insoluble base ->

Answer 8

Salt + water

Observation: solid disappears

Question 9

Salt

Answer 9

Produced when the H+ ion of an acid is replaced by a metal ion or NH4+.

Question 10

Hydrated salts

Answer 10

A salt that contains waters of crystallisation (water molecules trapped in the solid salt lattice) eg. CuSO4.5H2O

Question 11

Calculating the number of waters of crystallisation

Answer 11

They can be calculated in a similar way to calculating empirical formulae. Gently heat a hydrated salt to drive off the waters of crystallisation and leaving an anhydrous salt, calculate the mass of water loss, work out the mole ratio of anhydrous salt to water lost (divide masses by their respective formula masses, turn into a whole number ratio by dividing both by the smaller value.

Question 12

Titration method

Answer 12

Pipette a known volume of acid into a conical flask, add a few drops of indicator. Add alkali from a burette, swirling conical flask, add alkali until colour change (purple to colourless). Repeat without indicator.