Acids Bases And Salt Preparations

Question 1

Solubility and exceptions of sodium, potassium and ammonium

Answer 1

Solubility: soluble

Exceptions: none

Question 2

Solubility and exceptions of nitrates

Answer 2

Solubility - soluble

Exceptions - none

Question 3

Solubility and exceptions of chlorides

Answer 3

Solubility - soluble

Exceptions - silver chloride (AgCL) and Lead(II) chloride (PbCl2)

Question 4

Solubility and exceptions of sulfates

Answer 4

Solubility - soluble

Exceptions - barium sulfate (BaSO4), calcium sulfate (CaSO4) and lead(II) sulfate (PbSO4)

Question 5

Solubility and exceptions of carbonates

Answer 5

Solubility - insoluble

Exceptions - sodium carbonate (Na2CO3), potassium carbonate (K2CO3) and ammonium carbonate ((NH4)2CO3)

Question 6

Solubility and exceptions of hydroxides

Answer 6

Solubility - insoluble

Exceptions - sodium hydroxide (NaOH), potassium hydroxide (KOH) and calcium hydroxide (Ca(OH)2) (calcium hydroxide is slightly soluble)

Question 7

Acid + alkali

Answer 7

Water + salt

Often colourless salt is formed

Question 8

Base + acid

Answer 8

Water + salt
- bubbling is observed

Question 9

Carbonate + acid

Answer 9

Water + salt + carbon dioxide

Question 10

Metal + acid

Answer 10

Salt + hydrogen

• bubbling is observed
• only reacts with metals above hydrogen in reactivity series

Question 11

What is a base

Answer 11

A substance that neutralises an acid by combining with the hydrogen ions in them to produce water

Question 12

How do you prepare pure,dry crystals of copper sulfate from copper oxide and sulfuric acid

Answer 12

• heat sulfuric acid in a beaker
• add copper oxide in until no more copper oxide dissolves and stir with glass rod
• filter the mixture with filter paper and funnel to get rid of any excess copper oxide
• gently heat the filtered solution to evaporate some of the water
• heat until crystals form on a glass rod
• Remove crystals by filtration
• ;eave in warm area to dry

Question 13

How do you prepare a pure, dry sample of a soluble salt stating from an acid and alkali

Answer 13

-pipette 25cm3 of sodium hydroxide into a conical flask
- using titration, titrate the known volume of hydrochloric acid into a conical flask containing alkali
- transfer to evaporating basin and heat solution
- allow solution to cool so hydrated crystals form
- remove crystals by filtration and wash with distilled water
- dry by leaving in warm place

Question 14

How do you prepare a pure, dry sample of an insoluble salt starting from two soluble reactants

Answer 14

-mix silver chloride and silver nitrate solution together ( or any two soluble reactants )
- stir with a glass rod
- Filter using filter paper and funnel
- wash with distilled water
- dry by leaving in a warm place

To create lead sulfate, use lead nitrate and sodium sulfate solution