acids bases and alkalis

Question 1

what are bases and alkalis

Answer 1

Bases are substances that react with acids and neutralise them.
They are usually metal oxides, Many bases are insoluble - they do not dissolve in water.

If a base does dissolve in water, we call it an alkali.
Alkail is a base

Question 2

give an example of a base

Answer 2

Copper oxide is a base because it will react with acids and neutralise them and will not dissolve in water.

Question 3

give an example of an alkali

Answer 3

Sodium hydroxide is a base because it will react with acids and neutralise them. It’s also an alkali because it dissolves in water.

Question 4

A chemical reaction happens if you mix together an acid and a base. The reaction is called

Answer 4

Neutralisation

Question 5

Properties of Acids

Answer 5

1. taste sour (don’t taste them!)… the word ‘acid’ comes from the Latin acere, which means ‘sour’
2. acids change litmus (a blue vegetable dye) from blue to red
3. their aqueous (water) solutions conduct electric current (are electrolytes)
4. react with bases to form salts and water
   evolve hydrogen gas (H2) upon reaction with an active metal (such as alkali metals, alkaline earth metals, zinc, aluminum)

Question 6

Properties of Bases

Answer 6

taste bitter (don't taste them!)
feel slippery or soapy (don't arbitrarily touch them!)
bases don't change the color of litmus; they can turn red (acidified) litmus back to blue
their aqueous (water) solutions conduct and electric current (are electrolytes)
react with acids to form salts and water

Question 7

the names and formulas of some of the common acids

Answer 7

Hydrofluoric Acid - HF

Hydrochloric Acid - HC

Question 8

the names and formulas of some of the common

Answer 8

Sodium Hydroxide - NaOH
Potassium Hydroxide - KOH
Ammonium Hydroxide - NH4OH

Question 9

acid is neutralised with a base. What is the reaction

Answer 9

exothermic …gives out heat

Question 10

what is the pH scale

Answer 10

a universal indicator to establish level of acidity or alkalinity RED is acid Blue Alkali

Question 11

chemically what is the acid and alkali contain

write the formula for neutralising

Answer 11

acid positive hydrogen Ions H+
alkali Hydroxide negative Ions OH-
H+(aq) + OH-(aq) = H2O (l) Water !!!