Chapter 4 Flashcards
What is an acid
Chemical that releases H+ ions in an aqueous solution
Formula of: hydrochloric acid Sulfuric acid Nitric acid Ethanoic acid
HCl
H2SO4
HNO3
CH3COOH
What is dissociation
Splitting of acid to form H+ and an anion
Difference between a strong and weak acid
Strong acid fully dissociates in aqueous solution
Weak acid only partially dissociate
What is the pH of acid affected by
Strength of acid (strong/weak) and its concentration
Difference between strong and weak acid dissociation in equation form
Strong is one direction
Weak acid is a reversible reaction so both direction
Which of these is a weak acid
Hydrochloric, nitric, sulfuric, ethanoic
Ethanoic acid is weak
What is a base
Substance that neutralises an acid to form a salt
What is an alkali
Release OH- when dissolved in water
It is soluble in water and acts as a base
3 alkalis you need to know
NaOH
NH3
KOH
Formula of common bases
Not alkali
(2)
Metal carbonate and metal oxide
Word equation of a neutralisation reaction
Acid + base —> salt + water
Why isn’t the pH of (end products) neutralisation reaction always 7 (neutral)
It depends on volume and concentrations of acids used
As the acid may be limiting or in excess
Products of carbonate and acid
Salt
Water
Carbon dioxide
What is a titration experiment used for
To analyse unknown solutions
How do you ensure titre values are accurate and not a result of random errors
Have concordant results that are similar within a given range and workout its mean titre
How do you make a standard solution
Dissolve a compound of certain mass in water using a volumetric flask so you know its exact concentration
What is an oxidation number
Total number of electrons gained or lost from an atom to form a chemical bond
Oxidation number of Cl2
0
Order of priority in oxidation numbers
Grp 1 and 2 metals, F H O Cl Br I Everything else
What is the sum of oxidation numbers in compound equal to
Total charge
Preferences of oxidation number of following elements Grp 1 Grp 2 F H O Halogens
\+1 \+2 -1 \+1 -2 -1
What is oxidation number usually written as in a compound
In roman numerals in brackets
Which ones has higher priority in halogens for oxidation numbers
Cl or Br
Strength/priority decreases down the group so Cl
