OCR A Level Chemistry Paper 1 -
Periodic table, elements and
physical chemistry
Definition for rate of reaction - correct answearsthe change in concentration of a
reactant or product per unit of time
Definition of a covalent bond - correct answearsthe strong electrostatic attraction
between a shared pair of electrons and the nuclei of the bonded atoms
Definition of an ionic bond - correct answearsthe electrostatic attraction between 2
oppositely charged ions
Definition of an isomer - correct answearsatoms with the same number of protons but
different numbers of neutrons
Definition of an orbital - correct answearsa region of space that can hold up to two
electrons of opposite spin
Definition of electronegativity: - correct answearsthe ability of an atom to attract the pair
of electrons in a covalent bond to itself
Definition of relative atomic mass - correct answearsthe weighted mean mass of an
atom of an element compared to 1/12th of the mass of an atom of carbon-12
Does reactivity increase or decrease down group 2 and why - correct
answearsincreases because ionisation energies decrease due to the increasing atomic
radius and increased shielding
Does solubility increase or decrease down group 2 - correct answearsincrease
Equation to calculate the rate constant for first order reactions - correct
answearsk=ln2÷t₁/₂
Give the reaction for a group 2 element and a dilute acid - correct answearsM + 2HCl =
MCl2 + H2
Give the reaction for a group 2 element and oxygen - correct answears2M + O2 = 2MO
, Give the reaction for a group 2 element and water - correct answearsM + 2H2O =
M(OH)2 + H2
How do you calculate molality and what is molality measured in? - correct
answearsmolality = molarity x molar mass
molality is measured in gdm⁻³
How do you calculate the relative atomic mass of an isotope? - correct
answears(isotope mass x percentage) + (isotope mass x percentage) ÷ 100
How do you convert absorbance to concentration - correct answearsuse a calibration
curve
How do you use a colorimeter (3 steps) - correct answears1. set the colorimeter to the
wavelength of light you will be measuring
2. fill a cuvette with distilled water to calibrate the colorimeter. Set the absorbance to 0.
3. carry out the reaction, taking samples from the reaction mixture at regular intervals
and measure the absorbance of each sample
How does cis-platin work - correct answearsthe chloride ions are easily displaced so the
complex bonds to two nitrogen atoms on the DNA molecule, preventing the cell from
reproducing
How does half life change for the different orders - correct answearsfirst order, half life
is equal
second order, half life increases
zero order; half life decreases
How does having a lone pair affect bond angle? - correct answearsLone pairs repel
more than bonding pairs so for every lone pair take away 2.5° from the bond angle
How does ionic charge affect lattice enthalpy - correct answearsthe higher the charge,
the more energy is released when an ionic lattice forms due to stronger electrostatic
forces between the ions so the higher the charge the more exothermic the lattice
enthalpy.
How does ionic radii affect lattice enthalpy - correct answearsthe smaller the atomic
radii the more exothermic the lattice enthalpy as the ions can sit closer together
meaning that the attraction between the ions are stronger.
How many electrons can one orbital hold? - correct answears2
How many orbitals are there in a d sub-shell? - correct answears5
How many orbitals are there in a p sub-shell? - correct answears3
Periodic table, elements and
physical chemistry
Definition for rate of reaction - correct answearsthe change in concentration of a
reactant or product per unit of time
Definition of a covalent bond - correct answearsthe strong electrostatic attraction
between a shared pair of electrons and the nuclei of the bonded atoms
Definition of an ionic bond - correct answearsthe electrostatic attraction between 2
oppositely charged ions
Definition of an isomer - correct answearsatoms with the same number of protons but
different numbers of neutrons
Definition of an orbital - correct answearsa region of space that can hold up to two
electrons of opposite spin
Definition of electronegativity: - correct answearsthe ability of an atom to attract the pair
of electrons in a covalent bond to itself
Definition of relative atomic mass - correct answearsthe weighted mean mass of an
atom of an element compared to 1/12th of the mass of an atom of carbon-12
Does reactivity increase or decrease down group 2 and why - correct
answearsincreases because ionisation energies decrease due to the increasing atomic
radius and increased shielding
Does solubility increase or decrease down group 2 - correct answearsincrease
Equation to calculate the rate constant for first order reactions - correct
answearsk=ln2÷t₁/₂
Give the reaction for a group 2 element and a dilute acid - correct answearsM + 2HCl =
MCl2 + H2
Give the reaction for a group 2 element and oxygen - correct answears2M + O2 = 2MO
, Give the reaction for a group 2 element and water - correct answearsM + 2H2O =
M(OH)2 + H2
How do you calculate molality and what is molality measured in? - correct
answearsmolality = molarity x molar mass
molality is measured in gdm⁻³
How do you calculate the relative atomic mass of an isotope? - correct
answears(isotope mass x percentage) + (isotope mass x percentage) ÷ 100
How do you convert absorbance to concentration - correct answearsuse a calibration
curve
How do you use a colorimeter (3 steps) - correct answears1. set the colorimeter to the
wavelength of light you will be measuring
2. fill a cuvette with distilled water to calibrate the colorimeter. Set the absorbance to 0.
3. carry out the reaction, taking samples from the reaction mixture at regular intervals
and measure the absorbance of each sample
How does cis-platin work - correct answearsthe chloride ions are easily displaced so the
complex bonds to two nitrogen atoms on the DNA molecule, preventing the cell from
reproducing
How does half life change for the different orders - correct answearsfirst order, half life
is equal
second order, half life increases
zero order; half life decreases
How does having a lone pair affect bond angle? - correct answearsLone pairs repel
more than bonding pairs so for every lone pair take away 2.5° from the bond angle
How does ionic charge affect lattice enthalpy - correct answearsthe higher the charge,
the more energy is released when an ionic lattice forms due to stronger electrostatic
forces between the ions so the higher the charge the more exothermic the lattice
enthalpy.
How does ionic radii affect lattice enthalpy - correct answearsthe smaller the atomic
radii the more exothermic the lattice enthalpy as the ions can sit closer together
meaning that the attraction between the ions are stronger.
How many electrons can one orbital hold? - correct answears2
How many orbitals are there in a d sub-shell? - correct answears5
How many orbitals are there in a p sub-shell? - correct answears3
