What is the equation to calculate Ar?
referring to % abundance
∑ (isotopic mass x % abundance) / 100
What is an atomic orbital?
A region within an atom that can hold up to 2 electrons with opposite spins.
IT IS NOT A PLACE IT WILL BE MARKED INCORRECTLY
What is the shape of a P orbital?
What is the shape of an S orbital?
• dumbbell
• spherical
What is the formula for hydrochloric acid?
What is the formula for sulfuric acid?
What is the formula for nitric acid?
What is the formula for phosphoric acid?
•HCl
•H₂SO₄
•HNO₃
•H₃PO₄
What is the formula for methanoic acid?
What is the formula for ethanoic acid?
What is the formula for propanoic acid?
∙ HCOOH
∙ CH₃COOH
∙ C₂H₅COOH
What is an acid?
Releases H⁺ ions in aqueous solution
What is a strong acid?
Fully dissociate when dissolved in water
What is a weak acid?
Partially dissociate when dissolved water
What is a base?
A substance which neutralises acids OR a H⁺ acceptor
What is an alkali?
A soluble base that releases OH⁻ ions in aqueous solution
How are orbitals represented when showing the arrangement of electrons in subshells?
As boxes (or lines) with electrons represented as arrows.
What is the maximum number of electrons that an orbital can hold?
Two electrons.
What is the rule for how electrons occupy orbitals in a sub-shell?
Electrons occupy orbitals singly where possible due to charge repulsion.
When do electrons pair up in a sub-shell?
When forced to, e.g., when more electrons are present than the orbitals can hold singly.
What orbital is after 3p?
4s - has lower energy than 3d
What is a shorter way to write Electron configuration?
Using the Electron configuration of a noble gas
What 2 elements have exceptions to electron configuration?
•chromium
•copper
They show either a full or half-full sub shell and the structures are of lower energy and represent more stable arrangements
How do you write the electron configuration for ions?
Positive ions - electrons are removed from the highest energy orbitals
Negative ions - electrons are added to the highest energy orbitals
Examples of bases
•MgO
•BaO
•Mg(OH)₂
•CaCO₃
•NH₃
Alkalis release OH ions. What are 3 examples of reactions to show how they can react with water or dissociate to form OH ions?
•soluble metal hydroxides
•soluble metal oxides
•ammonia
What is a salt?
A compound where the H of the acid is replaced by a metal or another cation e.g. NH
What are the 4 examples of neutralisation reactions?
Acid + metal oxide —> salt + water
Acid + hydroxide —> salt + water
Acid + carbonate —> salt + carbon dioxide + water
Acid + ammonia —> ammonium salt
What colour does Phenolphthalein and Methyl orange turn in acid alkali and at neutralisation?
- P, acid = colourless, alkali = pink, neutral = pale pink
- MO, acid = red, alkali = yellow, neutral = orange
What is a titre?
the specific volume of a known concentration that is added from a burette to neutralise the solution in the conical flask
