Acids & Alkalis

Question 1

Acid properties

Answer 1

Aqueous solutions

pH less than 7

Source of hydrogen ions

Question 2

Alkali properties

Answer 2

Aqueous solution

pH over 7

Source of hydroxide ions

Question 3

The pH scale

Answer 3

measures the acidity or alkalinity of a solution. Goes from 0 (acidic) to 14 (alkali). 7 being neutral

Question 4

Concentration

Answer 4

A concentrated solution has a greater amount of dissolved solute particles than a dilute solution

Question 5

Strong acids

Answer 5

Strong acids fully dissociate into ions in solution . This means all their molecules release hydrogen ions

Question 6

Weak acids

Answer 6

Weak acids partially dissociate into ions in solution . This means only a few molecules release hydrogen ions.

Question 7

Q1) explain why sodium chloride dissolves in water to produce a solution with a pH of 6 while hydrogen chloride dissolved in water to produce a solution with a pH below 7

Answer 7

Sodium chloride solution is neutral meaning it doesn’t release hydrogen ions however hydrogen chloride is acidic meaning it does release hydrogen ions

Question 8

Q2) Explain why a concentrated example of ethanoic acid may have the same pH as a dilute sample of nitric acid

Answer 8

The concentration of hydrogen ions is the same

Question 9

Neutralisation reaction

Answer 9

A neutralization reaction is when an acid and a base react to form water and a salt and involves the combination of H+ ions and OH- ions to generate water. The neutralization of a strong acid and strong base has a pH equal to 7.

Question 10

Q3 - higher) Natural rainwater has a pH of 5. The most acidic rain ever recorded in Britain was 1000 times more acidic than natural rainwater. What was its pH? - High

Answer 10

2, If the hydrogen ion concentration in a solution increases by a factor of 10, the pH of the solution decreases by 1.