8.3 what is a base

Question 1

what is a base

Answer 1

a base is any metal oxide or hydroxide. they contain either the oxide ion or hydroxide ion

Question 2

most bases are _______ in water

Answer 2

insoluble

Question 3

base + acid →

Answer 3

salt + water

Question 4

alkalis

Answer 4

alkalis are bases that are soluble in water

Question 5

strong alkalis vs weak alkalis

Answer 5

like acids, bases (alkalis) can be strong or weak depending on their degree of ionisation

Question 7

properties of alkalis

Answer 7

• alkalis taste bitter
• alkalis feel slippery and soapy
• alkalis dissolve in water to form solutions that conduct electricity
• alkalis turn red litmus paper blue
• alkalis react with acids
• alkalis react with ammonium salts

Question 8

ionic equation for any neutralisation reaction between an acid and alkali

Answer 8

H⁺(aq) + OH⁻(aq) → H₂O(l)

Question 10

alkali + ammonium salt →

Answer 10

salt + water + ammonia

Question 11

when alkalis are heated with ammonium salt, they give off

Answer 11

ammonium gas