Acid and Bases

Question 1

what is a acid?

Answer 1

it is a substance that produces hydrogen ions, H+, when dissolved in water

Question 2

what is a strong acid?

Answer 2

it dissociates completely in water to produce hydrogen,H+, ions

Question 3

what is a weak acid?

Answer 3

it dissociates partially in water to produce hydrogen,H+, ions

Question 4

what are some properties of acids?

Answer 4

• produces hydrogen, H+, ions when dissolved in water
• turns blue litmus paper red
• tastes sour
• is corrosive
• turns green universal indicator red (strong acid) and orange (weak acid)\conducts electricity when dissolved in water
• has a PH less than 7

Question 5

what are some examples of strong acids?

Answer 5

• sulfuric acid
• nitric acid
• hydrochloric acid

Question 6

what is an example of a weak acid?

Answer 6

enthanoic acid

Question 7

what is the product between the reaction of an acid and a metal?

Answer 7

salt + hydrogen

Question 8

what is the product between the reaction of an acid and a metal carbonate?

Answer 8

salt + water + carbon dioxide

Question 9

what is the product between the reaction of an acid and an alkali?

Answer 9

salt + water

Question 10

what is the reaction between an acid and alkali called?

Answer 10

neutralisation

Question 11

how to test for hydrogen gas?

Answer 11

• place a lighted splint at the mouth of the test tube containing the gas to be tested
• if the gas is hydrogen, the lighted splint will extinguish with a ‘pop’ sound
• effervescence observed

Question 12

how to test for carbon dioxide gas?

Answer 12

• bubble the gas to be tested through a test tube containing lime water
• if the gas is carbon dioxide, a white precipitate will form

Question 13

what are some uses of ethanoic acid?

Answer 13

vinegar

Question 14

what is a base?

Answer 14

a substance that reacts with an acid to give salt and water

Question 15

what is an alkali?

Answer 15

a substance that produces hydroxide ions, OH-, when dissolved in water

Question 16

what is a strong alkali?

Answer 16

a substance that dissociates completely in water to produce hydroxide, OH-, ions

Question 17

what is a weak alkali?

Answer 17

a substance that dissociates partially in water to produce hydroxide, OH-, ions

Question 18

what are some properties of alkalis?

Answer 18

• produces hydroxide, OH-, ions
• turns red litmus paper blue
• tastes bitter
• feels slippery
• turns green universal indicator violet (strong alkali) and blue (weak alkali)
• conducts electricity when dissolved in water
• has a PH more than 7

Question 19

what are some common examples of alkalis?

Answer 19

• sodium hydroxide
• potassium hydroxide
• calcium hydroxide
• ammonium hydroxide

Question 20

what is the product between the reaction of an alkali and an acid?

Answer 20

salt + water

Question 21

what is the product between the reaction of an alkali and a ammonium salt?

Answer 21

salt + water + ammonia gas

Question 22

what are the polyatomic ions and their chemical formula?

Answer 22

• sulfate, SO4 2-
• carbonate, CO3 2-
• nitrate, NO3-
• hydroxide, OH-
• ammonium, NH4+

Question 23

what is the chemical formula for ammonia gas?

Answer 23

NH3

Question 24

how to test for ammonia gas?

Answer 24

• place a piece of moist red litmus paper at the mouth of the test tube containing the gas to be tested
• if the gas is ammonia, the moist red litmus paper will turn blue

Question 25

what is a PH scale?

Answer 25

a set of numbers used to indicate whether a solution is acidic, neutral or alkaline

Question 26

what can a PH scale be used for?

Answer 26

shows the strength of a acid or alkali

Question 27

what are some indicators?

Answer 27

- universal indicator | - PH probe

Question 28

what is the colour of acids in phenolphthalin?

Answer 28

colourless

Question 29

what is the colour of alkalis in phenolphthalin?

Answer 29

pink

Question 30

what is the colour of acids in methyl orange?

Answer 30

red

Question 31

what is the colour of alkalis in methyl orange?

Answer 31

yellow

Question 32

what is the colour of acids in litmus?

Answer 32

red

Question 33

what is the colour of alkalis in litmus?

Answer 33

blue

Question 34

how can we control soil PH?

Answer 34

- chemicals are used to adjust the PH value - acidic soils are treated with bases such as quick lime (calcium oxide) or slaked lime (calcium hydroxide) - this is known as 'liming' the soil

Question 35

what are the two categories that oxides are differentiated with?

Answer 35

metal oxides | non-metal oxides

Question 36

what are the two categories that non-metal oxides are differentiated with?

Answer 36

acidic oxides | neutral oxides

Question 37

what are examples of neutral oxides?

Answer 37

CO NO H2O

Question 38

what are the two categories that metal oxides are differentiated with?

Answer 38

basic oxides | amphoteric oxides

Question 39

what are examples of amphoteric oxides

Answer 39

ZnO Al2O3 PbO

Question 40

what does a basic oxide react with and what is formed in the reaction?

Answer 40

acid and they produce salt and water

Question 41

what does an acidic oxide react with and what is the product formed in the reaction?

Answer 41

bases and they produce salt and water

Question 42

what does a neutral oxide react with and what are its properties?

Answer 42

nothing | show neither acidic or basic properties, being insoluble in water

Question 43

what does a amphoteric oxide react with and what are its properties?

Answer 43

both acids and bases | behave as acids and alkalis, reacting with both acids and alkalis to form salt and water