acids and alkalis

Question 1

2:37 describe the reactions of hydrochloric acid, sulfuric acid and nitric acid with metals, bases and metal carbonates (excluding the reactions between nitric acid and metals) to form salts

Answer 1

alkali + acid → water + salt

     base      +      acid      →      water      +      salt 

     carbonate      +      acid      →      water      +      salt      +      carbon dioxide 

     metal   +   acid   →   salt   +   hydrogen 

Salts formed:

sulfuric acid (H2SO4 ) - sulfate (SO42 )

Hydrochloric acid (HCl) - chloride (Cl-)

Nitric acid (HNO3) - nitrate (NO3)

Question 2

2:38 know that metal oxides, metal hydroxides and ammonia can act as bases, and that alkalis are bases that are soluble in water

Answer 2

A base is a substance that contains hydroxide) H- ions and neutralizes an acid by combining it with the hydrogen H+ ions in it to produce water.

Examples:

metal oxide

metal hydroxide

Ammonia

Alkalis are bases which are soluble in water.

Question 3

1:20 understand how to use electrical conductivity and the acid-base character of oxides to classify elements as metals or non-metals

Answer 3

Metals:

conduct electricity

have oxides which are basic, reacting with acids to give a salt and water

Non – Metals:

do not conduct electricity (except for graphite)

have oxides which are acidic or neutral