UNIT 1- acids and bases

Question 1

what is the pH scale?

Answer 1

it is a continuous range from below 0 to above 14

Question 2

what is the pH of an acid?

Answer 2

LESS than 7

Question 3

what is the pH of an alkali?

Answer 3

MORE than 7

Question 4

what is the pH of pure water and neutral solution?

Answer 4

7

Question 5

how do you measure pH?

Answer 5

-compare the colour of the solution to a colour chart
-use electronic pH probes to accurately measure the pH

Question 6

what are acids?

Answer 6

they are compounds which produce H+(aq) ions when dissolved in water

Question 7

what are alkalis?

Answer 7

they are compounds which produce OH-(aq) ions when dissolved in water

Question 8

what is the formula and ions present for hydrochloric acid?

Answer 8

formula=HCl
ions present= H+(aq) & Cl-(aq)

Question 9

what is the formula and ions present for sulfuric acid?

Answer 9

formula=H2SO4
ions present= 2H+(aq) & SO4(2-)(aq)

Question 10

what is the formula and ions present for nitric acid?

Answer 10

formula=HNO3
ions present= H+(aq) & NO3-(aq)

Question 11

what is the formula and ions present for sodium hydroxide?

Answer 11

formula=NaOH
ions present=Na+(aq) & OH-(aq)

Question 12

what is the formula and ions present for pottasium hydroxide?

Answer 12

formula=KOH
ions present=K+(aq) & OH-(aq)

Question 13

what is the formula and ions present for calcium hydroxide?

Answer 13

formula=Ca(OH)2
ions present=Ca2+(aq) & 2OH-(aq)

Question 14

what do concentrated acids and alkalines contain?

Answer 14

a large amount of acid or alkali in a small volume of water

Question 15

what do dilute acids and alkalines contain?

Answer 15

a small amount of acid or alkali in a large volume of water

Question 16

what is equal in neutral solutions?

Answer 16

the concentration of H+(aq) ions and OH-(aq) ions

Question 17

what is a reversable reaction?

Answer 17

it is a reaction which can proceed in both directions

Question 18

what is equilibrium?

Answer 18

it is when the rate of the forward and reverse reactions are equal

Question 19

what happens at equilibrium?

Answer 19

the concentrations of reactants and products remain constant, although not necessarily equal

Question 20

what is the equation for equilibrium?

Answer 20

forward reaction(rp) = backward reaction(rb)

Question 21

what happens during equilibrium in water?

Answer 21

water molecules are constantly breaking up to form ions which in turn are constantly combining to reform water molecules

Question 22

what does equilibrium in water exist in?

Answer 22

it exists in pure water and all aqeous solutions

Question 23

what is the equation for equilibrium in water?

Answer 23

H2O <-> H+(aq) + OH-(aq)

Question 24

how many water molecules break up into ions? and what does this make water?

Answer 24

only 1 in every 55 million, therefore water is a poor conductor of electricity

Question 25

what is pH?

Answer 25

it is a measure of the hydrogen ion concentration

Question 26

what do acidic solutions contain?

Answer 26

more H+(aq) ions than pure water

Question 27

what do alkaline solutions contain?

Answer 27

more OH-(aq) ions than pure water

Question 28

what do neutral solutions contain?

Answer 28

they contain an equal amount of OH-(aq) ions and H+(aq) ions

Question 29

what happens if you add water to an acid?

Answer 29

the pH of the solution increases as the concentration of H+(aq) ions decreases

Question 30

what happens if you add water to an alkali?

Answer 30

the pH of the solution decreases as the concentration of OH-(aq) ions decrease

Question 31

what are all metal oxides?

Answer 31

all metal oxides are bases however not all bases are metal oxides

Question 32

what can non-metals burn in oxygen to produce?

Answer 32

they can burn in oxygen to produce non-metal oxides

Question 33

what happens when non-metal oxides dissolve in water?

Answer 33

they form acidic solutions

Question 34

what is formed if the metal oxide is soluble in water?

Answer 34

an alkali

Question 35

what do all soluble metal hydroxides dissolve in water to produce?

Answer 35

alkaline solutions

Question 36

what doesnt affect the pH of water?

Answer 36

insoluble oxides and hydroxides

Question 37

what is ammonia the common name for?

Answer 37

nitrogen hydride

Question 38

what is ammonia?

Answer 38

-it is a gas that will neutralise acids therefore it is a base -it is a covalent molecule which dissolves in water to produce an alkaline solution

Question 39

what happens during a neutralisation experiment?

Answer 39

-acids react with bases -the pH of the solution moves towards 7

Question 40

what are the bases?

Answer 40

-metal oxides -metal hydroxides -metal carbonates -ammonia

Question 41

what are the four main reactions of bases?

Answer 41

-acid + metal oxides = salt + water -acid + metal hydroxides = salt + water -acid + metal carbonate = salt + CO2 + water -acid + metal = salt + hydrogen

Question 42

what are some common acids?

Answer 42

-vinegar, -lemonade, -soda water, -coke,

Question 43

what are some common alkalis?

Answer 43

-baking soda, -dishwashing powder, -bleach,

Question 44

What acid causes acid rain?

Answer 44

Sulfur dioxide

Question 45

What is the test for oxygen?

Answer 45

Light a splint, then put it out, put the glowing splint up to the end of an open test tube, if the splint is relit then oxygen is present

Question 46

What is the test for carbon dioxide?

Answer 46

When carbon dioxide is shaken with or bubbled through limewater the limewater turns cloudy