AQA A-Level Chemistry ALL
TEST TUBE REACTIONS
-AQA A level Chemistry 3.1.8 –
Thermodynamics exam
QUESTIONS AND VERIFIED
CORRECT ANSWERS
GRADED A+ LATEST 100%
GUARANTEED PASS
Enthalpy of sublimation - CORRECT ANSWER-The enthalpy change when 1 mole of a solid
sublimes to form 1 mole of a gas.
Why are ionisation enthalpies always positive (endothermic)? - CORRECT ANSWER-Energy
needs to be put in to pull an electron away from the nucleus to overcome the electrostatic
attraction.
Why are first electron affinities always negative (exothermic)? - CORRECT ANSWER-Energy is
given out when an electron is attracted to the positively charged nucleus.
Why are second electron affinities and onwards always positive (endothermic)? - CORRECT
ANSWER-Energy needs to be put in to overcome the repulsion between an electron and a
negatively charged ion.
As the charge of ions increases, the lattice enthalpy... - CORRECT ANSWER-Increases.
, As the ionic radius increases, the lattice enthalpy... - CORRECT ANSWER-Decreases.
If there is "good agreement" between the experimental value (Born-Haber Cycle) and the
electrostatic attraction theory (Perfect Ion Theory) then the bonding is... - CORRECT ANSWER-
Pure ionic bonding.
If there is "significant difference" between the experimental value (Born-Haber Cycle) and the
electrostatic attraction theory (Perfect Ion Theory) then the bonding is... - CORRECT ANSWER-
Ionic bonding with some covalent character.
How much is a significant difference in the perfect ion theory? - CORRECT ANSWER-Over 7%.
As charge of CATION (+) increases, covalent character... - CORRECT ANSWER-Increases.
As ionic radius of CATION (+) increases, covalent character... - CORRECT ANSWER-Decreases.
As charge of ANION (-) increases, covalent character... - CORRECT ANSWER-Increases.
As ionic radius of ANION (+) increases, covalent character... - CORRECT ANSWER-Increases.
What is the symbol for entropy and what is it measured in? - CORRECT ANSWER-S
JK⁻¹mol⁻¹
When the number of molecules increases, entropy... - CORRECT ANSWER-Increases.
When the temperature increases, entropy... - CORRECT ANSWER-Increases.
TEST TUBE REACTIONS
-AQA A level Chemistry 3.1.8 –
Thermodynamics exam
QUESTIONS AND VERIFIED
CORRECT ANSWERS
GRADED A+ LATEST 100%
GUARANTEED PASS
Enthalpy of sublimation - CORRECT ANSWER-The enthalpy change when 1 mole of a solid
sublimes to form 1 mole of a gas.
Why are ionisation enthalpies always positive (endothermic)? - CORRECT ANSWER-Energy
needs to be put in to pull an electron away from the nucleus to overcome the electrostatic
attraction.
Why are first electron affinities always negative (exothermic)? - CORRECT ANSWER-Energy is
given out when an electron is attracted to the positively charged nucleus.
Why are second electron affinities and onwards always positive (endothermic)? - CORRECT
ANSWER-Energy needs to be put in to overcome the repulsion between an electron and a
negatively charged ion.
As the charge of ions increases, the lattice enthalpy... - CORRECT ANSWER-Increases.
, As the ionic radius increases, the lattice enthalpy... - CORRECT ANSWER-Decreases.
If there is "good agreement" between the experimental value (Born-Haber Cycle) and the
electrostatic attraction theory (Perfect Ion Theory) then the bonding is... - CORRECT ANSWER-
Pure ionic bonding.
If there is "significant difference" between the experimental value (Born-Haber Cycle) and the
electrostatic attraction theory (Perfect Ion Theory) then the bonding is... - CORRECT ANSWER-
Ionic bonding with some covalent character.
How much is a significant difference in the perfect ion theory? - CORRECT ANSWER-Over 7%.
As charge of CATION (+) increases, covalent character... - CORRECT ANSWER-Increases.
As ionic radius of CATION (+) increases, covalent character... - CORRECT ANSWER-Decreases.
As charge of ANION (-) increases, covalent character... - CORRECT ANSWER-Increases.
As ionic radius of ANION (+) increases, covalent character... - CORRECT ANSWER-Increases.
What is the symbol for entropy and what is it measured in? - CORRECT ANSWER-S
JK⁻¹mol⁻¹
When the number of molecules increases, entropy... - CORRECT ANSWER-Increases.
When the temperature increases, entropy... - CORRECT ANSWER-Increases.
