C8 Acids And Alkalis

Question 1

State the pH of a strong acid, strong alkali and neutral solution

Answer 1

1,14,7

Question 2

State three different indicators.

Answer 2

Litmus paper, universal indicator, methyl orange, phenolphthalein.

Question 3

Identify the indicator which turns pink in shampoo.

Answer 3

Shampoo is alkaline, phenolphthalein

Question 4

State the polyatomic ion formed when sulphuric acid dissociates.

Answer 4

SO4 2-

Question 5

The ____________ the pH the higher the concentration of hydrogen ions in solution.

Answer 5

Lower

Question 6

If the concentration of hydrogen ions increases by 1000 fold and the end result was pH 2, what pH did the first solution have?

Answer 6

1000 fold increase = 3 steps on the pH scale… pH5

Question 7

True or false there are no ions present in pH7 pure water.

Answer 7

False thee are equal numbers of hydroxide and hydrogen ions at low concentrations

Question 8

Strong acids…

Answer 8

Fully dissociate

Question 9

Weak acids…

Answer 9

Partially dissociate

Question 10

Name 3 strong acids

Answer 10

Hydrochloric, metric, sulphuric

Question 11

Name 3 weak acids

Answer 11

Boric, carbonic, ethanoic.

Question 12

Tin oxide is a base, describe how you would make tin chloride in a neutralisation reaction.

Answer 12

Mix excess tin oxide with hydrochloric acid, filter off excess. Rinse filter paper with distilled water, heat tin chloride solution in evaporating dish.

Question 13

Why is it critical to use excess copper oxide when making copper sulphate crystals in a neutralisation reaction?

Answer 13

So that all of the acid is neutralised.

Question 14

Nitrate ion

Answer 14

NO3 -1

Question 15

Charge of a sulphate ion

Answer 15

SO4 2-

Question 16

Charge of a carbonate ion

Answer 16

CO3 2-

Question 17

Formula for sodium sulphate

Answer 17

Na2SO4

Question 18

___________________ acid is found in the stomach because…

Answer 18

Hydrochloric acid… Help digest food, kill bacteria.

Question 19

Titration are used when…

Answer 19

Making soluble salts and a know endpoint is needed.

Question 20

Why is universal indicator a poor choice for titrations?

Answer 20

It doesn’t have a sharp end point like methyl orang of phenolphthalein

Question 21

Acid and limestone —>

Answer 21

Make salt, water and carbon dioxide

Question 22

Ionic equation for dissociation of ethanoic acid.

Answer 22

CH3COOH –> CH3COO- + H+

Question 23

Ionic equation for magnesium carbonate and hydrochloric acid…

Answer 23

2H+ + CO32- —> H2O + CO2
Extra brownie points for state symbols.
Magnesium and chloride ions are spectators.

Question 24

Common Sodium, potassium and ammonium salts tend to be…

Answer 24

Soluble

Question 25

All __________ are soluble

Answer 25

Nitrates

Question 26

Potassium chloride, silver chloride, lead chloride... Odd one out

Answer 26

Potassium chloride is soluble

Question 27

Name two suitable reagents to make barium sulphate in a precipitate reaction.

Answer 27

Barium nitrate, potassium/sodium/ammonium sulphate is the obvious choice :-)

Question 28

Turns limewater from colourless to cloudy...

Answer 28

Carbon dioxide.

Question 29

Charge on a hydroxide ion

Answer 29

-1

Question 30

Pipettes are used in titrations instead of measuring cylinders because...

Answer 30

They provide a more accurate and repeatable means of measuring out a know volume of liquid.

Question 31

Dodgy titration, how do you ensure your result is reliable?

Answer 31

Repeat your experiment.

Question 32

A student has 100ml of sodium hydroxide solution, it is neutralised in a titration by 25ml of an acid stock. What does this tell you about the acid?

Answer 32

The concentration of the acid is 4 times greater in magnitude.

Question 33

What did the police officer say to the acid who hit an alkali?

Answer 33

That's assault!

Question 34

It's all about the base, bout the base...

Answer 34

No acid.

Question 35

If your not part of the solution...

Answer 35

Your part of the precipitate.

Question 36

What's effervescence? When might you see it in this topic?

Answer 36

Bubbles! Bubbles! CASHOCO reactions, MASH reactions.

Question 37

25g of sulphuric acid is dissolved into 200cm3 of water, what's the concentration?

Answer 37

0.125g/cm3

Question 38

Write the formula and state symbol for a saline solution.

Answer 38

NaCl (aq)

Question 39

Describe a concentrated acid

Answer 39

Large number of hydrogen ions in a proportionally small volume.

Question 40

Describe a strong acid

Answer 40

An acid which is a strong proton donor and reliably dissociates with high percentage of success.