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 m