10D- comparing pH measurements

Question 1

Define commercial indicator

Answer 1

An artificially prepared indicator

Question 2

Define indicator

Answer 2

A substance that changes colour to indicate a pH range

Question 3

Define litmus paper

Answer 3

Paper used to indicate the acidity or basicity of a substance

Question 4

Define natural indicator

Answer 4

An indicator made from naturally sourced substances

Question 5

Define pH meter

Answer 5

An instrument used to measure the pH of a substance

Question 6

Acidity
definition(adj.)

Answer 6

-Acidity(adj.)=The
amount of acid in a substance

Question 7

Alkalinity
definition(adj.)

Answer 7

-Alkalinity(adj.)=The
ability to neutralise an acid

Question 8

Definition of proticity(aka basicity)

Answer 8

The number of replaceable hydrogens in the formula of an inorganic acid is called Basicity. Basicity is also known as Proticity

Question 9

Define super acid

Answer 9

Super acid
definition=A superacid can be defined as an acid that is stronger than 100%
sulfuric acid.

Question 10

Define super base

Answer 10

Inchemistry, asuperbaseis an extremely strongbase. There is no commonly accepted
definition for what qualifies as a superbase, but most chemists would
acceptsodium hydroxideas a ‘benchmark’ base just
assulfuric acidis a ‘benchmark’ acid
(seesuperacid).

Question 11

how can we approximate pH

Answer 11

indicators- chemical compounds that change colours depending on the pH they are immersed in

Question 12

what colour does litmus paper turn

Answer 12

blue litmus paper turns red in an acidic solution
red litmus paper turns blue in a basic solution

Question 13

what are natural indicators

Answer 13

an indicator made from naturally sourced substances

Question 14

what are commercial indicators

Answer 14

indicators that are prepared artificially

Felix=Indicators that are synthesised/man made

Question 15

list some natural indicators

Answer 15

red litmus
blue litmus
turmeric
red cabbage juice
Coloured petals of some flowers such as hydrangea

Question 16

list some commercial indicators

Answer 16

phenolphthalein
methyl violet
methyl orange
thymolphthalein
Universal indicator

Question 17

what does red litmus paper indicate

Answer 17

acid: red
base: blue
changes colour at pH of=7(CHECK)

Question 18

what does blue litmus paper indicate

Answer 18

acid: blue
base: red
changes colour at pH of=7(CHECK)

Question 19

what does turmeric indicate

Answer 19

acid: yellow
base: reddish brown
changes colour at pH of=7.4 and 8.6

Question 20

what does red cabbage juice indicate

Answer 20

acid: reddish
base: greenish yellow
changes colour at pH of=7

Question 21

what does phenolphthalein indicate

Answer 21

acid: colourless
base: pink
changes colour at pH of=8.3-10.0

Question 22

what does methyl violet indicate

Answer 22

acid: yellow
base: blue
changes colour at pH of=0.0-1.6

Question 23

what does methyl orange indicate

Answer 23

acid: red
base: yellow
changes colour at pH of=3.1-4.4

Question 24

what does thymolphthalein indicate

Answer 24

acid: colourless
base: blue
changes colour at pH of= 9.3 - 10.5

Question 25

how can more specific pH measurements be obtained

Answer 25

pH meters can be used to provide a specific, quantitative measurement of pH
they measure the difference in electrical potential between two probes due to the concentration of charged particles/ion in the solution

Question 26

what are strong acid pH’s

Answer 26

a solution with a pH of 3 or less is considered a strong acid

Question 27

what are strong base pH’s

Answer 27

a solution with a pH of 10 or higher is considered to be a strong base

Question 28

what pH does the universal indicator cover

Answer 28

0 to 14

Question 29

indicators accuracy and precision

Answer 29

low accuracy and low precision
indicators can only approximate pH range and the estimated pH of a given solution may differ greatly between trials

Question 30

calibrated pH meters accuracy and precision

Answer 30

high accuracy and high precision

Question 31

what is the accuracy of most pH meters

Answer 31

+-0.01 pH units

Question 32

What are the three types of indicators

Answer 32

1)natural indicators
2)Commercial indicators
3)pH meters

Question 33

What is a pH meter
and what does it measure, and how does it measure it.

Answer 33

-pH meter=
instrument= measures acidity or alkalinity in a solution
-pH meter does
this by reading the hydrogen ion concentration in the solution

Question 34

What is precision
and what is accuracy.

Answer 34

-precision and
accuracy=two ways to describe results when completing a process that is
repeated=
-precision=yield
results that are close to each other repeatedly
-accuracy=yield
results being close to the accepted or true value of the test.

Question 35

Colour or
universal indicator across pH

Answer 35

Imagine it as a
rainbow, with pH of 7 showing green. Anything less then pH 7 changes
substance colour towards red, and any pH more than 7 changes substance colour
towards purple.