Acids and alkalis *

Question 1

What is an acid?

Answer 1

a solution that contains H+ ions, turns litmus red and has a pH of less than 7

Question 2

What is a base?

Answer 2

a substance that will react with an acid to form only salt and water

Question 3

What is an alkali?

Answer 3

a solution that contains OH- ions, turns litmus blue and has a pH greater than 7
soluble base

Question 4

Values below 7 on the pH scale :

the ______ the pH number, the _______ the concentration of H+ ions in the solution and the ______ the acid

Answer 4

the lower the pH number, the higher the concentration of H+ ions in the solution and the stronger the acid

Question 5

Values above 7 on the pH scale :

the ______ the pH number, the _______ the concentration of OH- ions in the solution and the ______ the alkali

Answer 5

the higher the pH number, the higher the concentration of OH- ions in the solution and the stronger the alkali

Question 6

What happens at 7 on the pH scale?

Answer 6

the H+ ions and the OH- ions balance each other out, making the solution neutral

Question 7

What are the products to these acid reactions?

acid + base –>
acid + alkali –>
acid + metal –>
acid + metal carbonate –>

Answer 7

acid + base –> salt + water
acid + alkali –> salt + water
acid + metal –> salt + hydrogen
acid + metal carbonate –> salt + water + carbon dioxide

Question 8

What is a salt?

Answer 8

a compound formed by neutralisation of an acid by a base

Question 9

What is neutralisation?

Answer 9

a reaction in which an acid reacts with a base to produce a salt and water only

Question 10

What are the products to these neutralisation reactions?

acid + metal hydroxide –>
acid + metal oxide –>
acid + metal carbonate –>
acid + ammonium hydroxide –>
acid + ammonia solution –>

Answer 10

acid + metal hydroxide –> salt + water
acid + metal oxide –> salt + water
acid + metal carbonate –> salt + water + carbon dioxide
acid + ammonium hydroxide –> ammonium salt + water
acid + ammonia solution –> ammonia salt