Acids, Alkali and reactions (Yr7)

Question 1

what is a acid

Answer 1

a reactive compound that dissolves in water and contains hydrogen at at least one other non metal

Question 2

neutralisation

Answer 2

a reaction between acid and alkalis that makes a salt and leaves the solution with a pH of of 7

Question 3

alkali

Answer 3

anything that can neutralise a acid and dissolves in water producing a pH of more than 7

Question 4

indicator

Answer 4

something that produces a colour change in the presence of a substance

Question 5

universal indicator

Answer 5

an indicator with a different colour for each pH value

Question 6

pH and hair colour

Answer 6

Alkali opens the outer layer (cuticle) of the hair and allows colour in. Acid is then used to close the cuticle again

Question 7

pH and plants

Answer 7

different plants thrive in different soil pHs. Limescale is used to neutralise soil if it becomes too acidic

Question 8

Hydrogen

Answer 8

the smallest and most abundant element in the universe. you can test the presence of hydrogen by using a lit splint. It produces a squeaky pop when lit

Question 9

Carbon Dioxide

Answer 9

a gas that is produced when carbon burns or when carbonates react with acid. The test for carbon dioxide is that it turns limewater milky when it is bubbled through it

Question 10

Acid and limescale

Answer 10

limescale can build up on heating elements or bath taps. It’s chemical name is calcium carbonate and so it can be removed using acid

Question 11

acids and salts

Answer 11

hydrochloric acid makes chloride salts
Sulfuric acids makes sulfates
Nitric acid makes nitrates

Question 12

concentration

Answer 12

the amount of a substance present per unit volume