Acids And Bases N5 U1 P5

Question 1

What does the pH scale indicate, and determines

Answer 1

Acidic, neutral or alkaline
The ratio of hydrogen ions to hydroxide ions

Question 2

Ph of neutral solutions

Answer 2

Water contains an equal concentration of H+ AND OH-, pH of 7

Question 3

Ph of acidic solutions

Answer 3

Sources of H+ ions
pH below 7

Question 4

PH of alkaline solutions

Answer 4

Sources of OH- ions
pH above 7

Question 5

Water and neutral solutions

Answer 5

H2O[l] = H+[aq] +OH-[aq]
Only a few water molecules dissociated into free ions
= indicates the reaction is reversible

Question 6

Dilution of acids and alkali reaction

Answer 6

Dilution can be tracked using a chemical indicator
Alkali added to acid, becomes more alkaline
Acid added to alkali, becomes more acidic

Question 7

Forming acids and alkali

Answer 7

Formed by dissolving different oxides in water

Question 8

Formation of acids

Answer 8

Soluble non-metal oxides dissolves in water
Non-metal oxide+ water -> acid

Question 9

Formation of alkali

Answer 9

Soluble metal oxides or hydroxides dissolve in water
Metal oxide+ water -> alkali

Question 10

Formation of a base

Answer 10

Neutralises an acid
Insoluble metal oxides, hydroxides or carbonates
All alkalis are bases, but not all baes are alkalis

Question 11

Neutralisation reaction

Answer 11

Base reacts with acid to form water and salt
Acid+base= salt+water

Question 12

Naming salt- sodium hydroxide and hydrochloric acid

Answer 12

Base- sodium hydroxide
Base is the salt name start- sodium
Acid- hydrochloric acid
Acid is salt name end- chloride

Question 13

Neutralisation of an acid

Answer 13

Adding an alkali to an acid will increase the pH to 7

Question 14

Neutralisation of an alkali

Answer 14

Adding an acid to an alkali will decrease the pH towards 7

Question 15

Neutralisation reactions- different bases

Answer 15

Metal oxide+acid->salt+water
Metal hydroxides+acids->salt +water
Metal carbonates+acid->salt+water+carbon dioxide

Question 16

Spectator ions

Answer 16

Present in the equation but remain chemically unchanged
Reacting species shown by removing spectator ions

Question 17

Spectator ion equation- metal oxides

Answer 17

2H+[aq]+O2[s]->H2O[l]

Question 18

Spectator ion equation- metal hydroxides

Answer 18

H+[aq]+OH-[aq]->H2O[l]

Question 19

Spectator ion equations- aqueous metal carbonates

Answer 19

2H+[aq]+CO3,2-[aq]->H2O[l]+CO2[g]

Question 20

Spectator ion equation- insoluble metal carbonates

Answer 20

2H+[aq]+CO3,2-[s]->H2O[l]+CO2[g]

Question 21

Titration experiment

Answer 21

Unmeasured volume of one solution is added to a known volume of another solution until neutral
Indicator
Repeated until concordant results
Produce a soluble salt

Question 22

Titration apparatus

Answer 22

Burette and pipette
When drawing apparatus burette must have graduation marks
Pipette has one graduation mark as is measures one volume

Question 23

Titration calculations

Answer 23

Has to be a balanced chemical equation
1- data box- acid and base
2-calculate known quantity n over cv
3- identify mole ratio
4- calculate c1V1=c2V2
n1 n2
No.1 divide by no.2= c2[unkown concentration]