Unit 5 Applied science level 3 BTEC
Chemistry questions and answers 2025/2026
grade A
chemical energy - answerthe energy required to break or make bonds
exothermic reaction - answerA reaction that releases more energy in the form of heat
what is the enthalpy change of an exothermic reaction - answernegative
endothermic reaction - answerA reaction in which more energy is absorbed
what is the enthalpy charge of an endothermic reaction - answerpositive
what will happen to the enthalpy diagrams when a catalyst is added - answerless activation energy will
be required during this reaction
enthalpy change - answerthe change n eat energy at a constant pressure
Enthalpy change of formation - answerwhen one mole of a compound is formed from its element under
standard conditions
enthalpy change of combustion - answerwhen one mole of a substance is burnt in oxygen under
standard conditions
enthalpy change of hydration - answerwhen one mole of a gaseous ion are dissolved in water to make
an infinite dilute solution
what are the three standard conditions - answertemperature
concentration
, pressure
what are the units for the three standard conditions - answertemperature- 298k
concentration- 1mol dm-3
pressure- 100kpa
what is the equation for enthalpy change - answerchange in internal energy + pressure x change in value
how o you convert Celsius to kelvin - answer+ 273
What is a catalyst? - answera substance that speeds up the rate of reaction by decreasing the activation
energy needed for the reaction, so it provides the reaction with an alternate pathway. the catalyst is
never used up throughout the reaction
What is Hess's Law? - answerThe total enthalpy change of a reaction is independent of the route taken.
What is lattice energy? - answerthe energy required to make one mole of an ionic lattice
what is the homologous series? - answerA group of chemicals that react in a similar way because they
have the same functional group
what type of bond is an alkane? - answersingle
what type of bond is an alkene? - answerDouble
what type of bond is an alkyne - answerTripple
what is the general equation for an alkane? - answerCn2H2n+2
what is the general equation for an alkene? - answerCn2H2n
Chemistry questions and answers 2025/2026
grade A
chemical energy - answerthe energy required to break or make bonds
exothermic reaction - answerA reaction that releases more energy in the form of heat
what is the enthalpy change of an exothermic reaction - answernegative
endothermic reaction - answerA reaction in which more energy is absorbed
what is the enthalpy charge of an endothermic reaction - answerpositive
what will happen to the enthalpy diagrams when a catalyst is added - answerless activation energy will
be required during this reaction
enthalpy change - answerthe change n eat energy at a constant pressure
Enthalpy change of formation - answerwhen one mole of a compound is formed from its element under
standard conditions
enthalpy change of combustion - answerwhen one mole of a substance is burnt in oxygen under
standard conditions
enthalpy change of hydration - answerwhen one mole of a gaseous ion are dissolved in water to make
an infinite dilute solution
what are the three standard conditions - answertemperature
concentration
, pressure
what are the units for the three standard conditions - answertemperature- 298k
concentration- 1mol dm-3
pressure- 100kpa
what is the equation for enthalpy change - answerchange in internal energy + pressure x change in value
how o you convert Celsius to kelvin - answer+ 273
What is a catalyst? - answera substance that speeds up the rate of reaction by decreasing the activation
energy needed for the reaction, so it provides the reaction with an alternate pathway. the catalyst is
never used up throughout the reaction
What is Hess's Law? - answerThe total enthalpy change of a reaction is independent of the route taken.
What is lattice energy? - answerthe energy required to make one mole of an ionic lattice
what is the homologous series? - answerA group of chemicals that react in a similar way because they
have the same functional group
what type of bond is an alkane? - answersingle
what type of bond is an alkene? - answerDouble
what type of bond is an alkyne - answerTripple
what is the general equation for an alkane? - answerCn2H2n+2
what is the general equation for an alkene? - answerCn2H2n
