OCR Chemistry A-Level - Modules 1-4 exam
with verified solutions
what is water of crystallisation? - correct answer ✔water molecules that make
| | | | | | | | | | |
up part of the crystal structure of a solid
| | | | | | | | |
define relative isotopic mass - correct answer ✔the ass of an atom of an
| | | | | | | | | | | | |
isotope of an element relative to one twelfth the mass of an atom of C-12
| | | | | | | | | | | | | | |
why is relative atomic mass written as a decimal? - correct answer ✔it is a
| | | | | | | | | | | | | |
weighted average mass
| | |
define molecular formula - correct answer ✔the actual number of atoms of
| | | | | | | | | | |
each element in a compound
| | | | |
define what an orbital is - correct answer ✔a region within an atom that can
| | | | | | | | | | | | | |
hold up to two electrons of opposite spins
| | | | | | | |
what shape are S orbitals? - correct answer ✔spherical
| | | | | | | |
what shape are orbitals? - correct answer ✔figure of 8
| | | | | | | | |
how can you make out the electron structure of an element using the periodic
| | | | | | | | | | | | |
table? - correct answer ✔period = energy level
| | | | | | | | |
, columns = electrons | | |
group = subshell | |
show the oxidation of sodium and the reduction of chlorine - correct answer
| | | | | | | | | | | |
✔Na -> Na+ + e-
| | | | |
Cl + e- -> Cl-
| | | |
ions always go on the RHS whether oxidation or reduction
| | | | | | | | |
define ionic bond - correct answer ✔the electrostatic force of attraction
| | | | | | | | | |
between positive and negative ions
| | | | |
ionic bonding occurs between metals and non-metals but which ion is the
| | | | | | | | | | |
|exception? - correct answer ✔NH4+ | | | |
define covalent bond - correct answer ✔the strong electrostatic force of
| | | | | | | | | |
attraction between the shared pair of electrons and the nuclei of the bonded
| | | | | | | | | | | | |
atoms
|
when non-metals covalently bond, what is their aim? - correct answer ✔the
| | | | | | | | | | |
octet rule:
| |
- to reach a noble gas configuration (8 electrons in the outer shell)
| | | | | | | | | | | |
what are there exceptions to the octet rule? - correct answer ✔- NO (odd
| | | | | | | | | | | | |
number of electrons)
| | |
- BF3 (boron has less than 8 outershell electrons)
| | | | | | | |
with verified solutions
what is water of crystallisation? - correct answer ✔water molecules that make
| | | | | | | | | | |
up part of the crystal structure of a solid
| | | | | | | | |
define relative isotopic mass - correct answer ✔the ass of an atom of an
| | | | | | | | | | | | |
isotope of an element relative to one twelfth the mass of an atom of C-12
| | | | | | | | | | | | | | |
why is relative atomic mass written as a decimal? - correct answer ✔it is a
| | | | | | | | | | | | | |
weighted average mass
| | |
define molecular formula - correct answer ✔the actual number of atoms of
| | | | | | | | | | |
each element in a compound
| | | | |
define what an orbital is - correct answer ✔a region within an atom that can
| | | | | | | | | | | | | |
hold up to two electrons of opposite spins
| | | | | | | |
what shape are S orbitals? - correct answer ✔spherical
| | | | | | | |
what shape are orbitals? - correct answer ✔figure of 8
| | | | | | | | |
how can you make out the electron structure of an element using the periodic
| | | | | | | | | | | | |
table? - correct answer ✔period = energy level
| | | | | | | | |
, columns = electrons | | |
group = subshell | |
show the oxidation of sodium and the reduction of chlorine - correct answer
| | | | | | | | | | | |
✔Na -> Na+ + e-
| | | | |
Cl + e- -> Cl-
| | | |
ions always go on the RHS whether oxidation or reduction
| | | | | | | | |
define ionic bond - correct answer ✔the electrostatic force of attraction
| | | | | | | | | |
between positive and negative ions
| | | | |
ionic bonding occurs between metals and non-metals but which ion is the
| | | | | | | | | | |
|exception? - correct answer ✔NH4+ | | | |
define covalent bond - correct answer ✔the strong electrostatic force of
| | | | | | | | | |
attraction between the shared pair of electrons and the nuclei of the bonded
| | | | | | | | | | | | |
atoms
|
when non-metals covalently bond, what is their aim? - correct answer ✔the
| | | | | | | | | | |
octet rule:
| |
- to reach a noble gas configuration (8 electrons in the outer shell)
| | | | | | | | | | | |
what are there exceptions to the octet rule? - correct answer ✔- NO (odd
| | | | | | | | | | | | |
number of electrons)
| | |
- BF3 (boron has less than 8 outershell electrons)
| | | | | | | |
