2.1.4 - Acids

Question 1

What’s the formula of Hydrochloric Acid?

Answer 1

HCl

Question 2

What’s the formula of Sulfuric Acid?

Answer 2

H₂SO₄

Question 3

What’s the formula of Nitric Acid?

Answer 3

HNO₃

Question 4

What’s the formula of Ethanoic Acid?

Answer 4

CH₃COOH

Question 5

What do Acids release when dissolved in water?

Answer 5

When dissolved in water, an acid releases hydrogen ions (H+)

Question 6

Define a ‘Strong Acid’

Answer 6

Such as HCl, releases all its hydrogen atoms into solution as H+ ions and completely dissociates (splits up) in aqueous solution.

Question 7

Define ‘Weak Acid’

Answer 7

such as ethanoic acid, CH3COOH, only releases a small proportion of its available hydrogen atoms into solution as H+ ions. A weak acid partially dissociates in aqueous solution.

Question 8

Define an Alkali

Answer 8

An alkali is a base that dissolves in water, releasing hydroxide ions (OH-) into the solution.

Question 9

Are Metal Oxides bases/Alkalies?

Answer 9

Base only

Question 10

Are Metal Carbonates bases/Alkalies?

Answer 10

Base only

Question 11

Are Metal Hydroxides (SOLID) bases/Alkalies?

Answer 11

Base only

Question 12

Are Metal Hydroxides (DISSOLVED) bases/Alkalies?

Answer 12

Alkali & Base

Question 13

What is the salt formed with HCl

Answer 13

Metal Chloride

Question 14

What is the salt formed with H₂SO₄

Answer 14

Metal Sulfate

Question 15

What is the salt formed with HNO₃

Answer 15

Metal Nitrate

Question 16

What does ‘Base + Acid’ produce?

Answer 16

salt + water

Question 17

What does ‘Alkali + Acid’ produce?

Answer 17

salt + water

Question 18

What does ‘Carbonate + Acid’ produce?

Answer 18

salt + water + carbon dioxide

Question 19

What is a Tritation?

Answer 19

A titration is a technique used to accurately measure the volume of one solution that reacts exactly with another solution. Titrations can be used:

Question 20

What is a standard solution?

Answer 20

A standard solution is a solution of known concentration. A volumetric flask is used to make up a standard solution very accurately.

Question 21

What is the procedure for preparing a standard solution?

Answer 21

(1) Weigh the solid accurately

(2) Dissolve the solid in a beaker using less distilled water than needed to fill the volumetric flask

(3) Transfer the solution to a volumetric flask, then rinse the last traces with distilled water into the flask

(4) Fill the flask to the graduation line with destilled water until the bottom of the meniscus lines up exactly with the mark.

Question 22

What is the procedure of an Acid-base titration?

Answer 22

(1) Add a standard solution to a conical flask using a pipette
(2) Add a few drops of indicator to the solution
(3) Add the other solution to the burette & record the initial burette reading to the nearest 0.05
(4) Do a trial titration first
(5) Add the solution of the burette to the solution of the conical flask slowly, go drop by drop, when reaching the average amount you got in your trial titre. Mix the solution in a conical flask while adding it from the burette. The point is when the solution changes colour.
(6) Record final burette reading. Volume added to the conical flask is called the titre (initial reading - final reading)
(7) Repeat titration 2 more times (concordant titres = within 0.10 of each other)

Question 23

How does workout mean titre?

Answer 23

Concordant Results are added together and then divided by how many of concordant results there were.

Question 24

What is ‘Absolute Uncertainty’?

Answer 24

This is the actual uncertainty in a reading taken using a specific piece of apparatus. The value depends on the apparatus used.

Question 25

Define 'measurements'

Answer 25

the values taken as the difference between the judgements of two values.

Question 25

Define 'readings'

Answer 25

The values found from a single judgement when using a piece of equipment

Question 26

How do you read 'Uncertainty'?

Answer 26

EXAMPLE: If the graduations on the ruler are every 1 𝑚𝑚, then each reading (once at the zero mark and once at the end point of the object) contributes an uncertainty of ±0.5 𝑚𝑚, hence, the uncertainty on the length of the object is ±1 𝑚𝑚.