What is the relative mass of an electron?
1/200
1/2000
1/20
1
A negative charge means that there's more protons than electrons
What did Bohr discover?
Protons
Electrons
Neutrons
Ions
Shells
Noble gases are inert
Plum pudding model
Atoms are solid spheres
The nucleus is positively charged
Relative isotopic mass is the average mass of a molecule compared to 1/12 of the mass of an atom of carbon-12
What is the equation linking moles, mass and molar mass?
Moles = molar mass / mass
Molar mass = moles / mass
Moles = mass / molar mass
If concentration temperature( concentration, temperature ) and pressure stay the same, one mole of any gas always has the same volume mass partial pressure( volume, mass, partial pressure ) - this is known as the molar gas volume (moldm⁻³ dm³mol⁻¹ gdm⁻³( moldm⁻³, dm³mol⁻¹, gdm⁻³ )).
Acids are proton acceptors
H⁺ ions can never exist by themselves in water
What are the products of a reaction between acids and bases?
Salt and water
Salt and hydrogen
Salt, carbon dioxide and water
Salt
What are the products of acids and metal hydroxides?
Salt and metal oxides
The water in a lattice is called . A solid salt containing water of crystallisation is . A salt is if it doesn't contain water of crystallisation.
In the presence of an acid, what colour does methyl orange turn?
Red
Yellow
Pink
Orange
Colourless
In the presence of an alkali, what colour does phenolphthalein turn?
Compared to a monoprotic acid, you'll need to double the number of moles of base to neutralise a diprotic acid
The actual mass/yield will always be than the theoretical yield as not all chemicals fully and some chemicals are between transfers
In a substitution reaction, the atom economy is always less than 100%
What are the CORRECT rules for oxidation numbers?
Uncombined elements (or elements bonded to identical atoms) have an oxidation number of 0
Oxygen always has an oxidation number of -2
Hydrogen always has an oxidation number of +1, except in metal hybrids where it's -1 and molecular hydrogen where it's 0
The sum of the oxidation numbers for a neutral compound is 0
For molecular ions, each of the constituent atoms has the same oxidation number of as the molecule's overall charge
Oxidation is a gain in electrons
In the reaction below, which elements have been oxidised and which have been reduced: 2K + H₂SO₄ --> K₂SO₄ + H₂
K has been oxidised, H has been reduced
H has been oxidised, K has been reduced
S has been oxidised, K has been reduced
K has been oxidised, S has been reduced
What is the chemical formula of sulphate (VI) ions?
SO₃²⁻
SO₄²⁻
SO₃⁻
SO₄⁻
