APPLIED SCIENCE LEVEL 3
BTEC CHEMISTRY UNIT
5 EXAM WITH CORRECT
ANSWERS GRADED A+
QUESTIONenthalpy change - answer-the change n eat energy at
a constant pressure
QUESTIONEnthalpy change of formation - answer-when one
mole of a compound is formed from its element under standard
conditions
chemical energy - answer-the energy required to break or make
bonds
QUESTIONexothermic reaction - answer-A reaction that releases
more energy in the form of heat
QUESTIONwhat is the enthalpy change of an exothermic reaction
- answer-negative
QUESTIONendothermic reaction - answer-A reaction in which
more energy is absorbed
, QUESTIONwhat is the enthalpy charge of an endothermic
reaction - answer-positive
QUESTIONwhat will happen to the enthalpy diagrams when a
catalyst is added - answer-less activation energy will be required
during this reaction
QUESTIONenthalpy change of combustion - answer-when one
mole of a substance is burnt in oxygen under standard conditions
QUESTIONenthalpy change of hydration - answer-when one
mole of a gaseous ion are dissolved in water to make an infinite
dilute solution
QUESTIONwhat are the three standard conditions - answer-
temperature
concentration
pressure
QUESTIONwhat are the units for the three standard conditions -
answer-temperature- 298k
concentration- 1mol dm-3
pressure- 100kpa
QUESTIONwhat is the equation for enthalpy change - answer-
change in internal energy + pressure x change in value
QUESTIONhow o you convert Celsius to kelvin - answer-+ 273
QUESTIONWhat is a catalyst? - answer-a 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
BTEC CHEMISTRY UNIT
5 EXAM WITH CORRECT
ANSWERS GRADED A+
QUESTIONenthalpy change - answer-the change n eat energy at
a constant pressure
QUESTIONEnthalpy change of formation - answer-when one
mole of a compound is formed from its element under standard
conditions
chemical energy - answer-the energy required to break or make
bonds
QUESTIONexothermic reaction - answer-A reaction that releases
more energy in the form of heat
QUESTIONwhat is the enthalpy change of an exothermic reaction
- answer-negative
QUESTIONendothermic reaction - answer-A reaction in which
more energy is absorbed
, QUESTIONwhat is the enthalpy charge of an endothermic
reaction - answer-positive
QUESTIONwhat will happen to the enthalpy diagrams when a
catalyst is added - answer-less activation energy will be required
during this reaction
QUESTIONenthalpy change of combustion - answer-when one
mole of a substance is burnt in oxygen under standard conditions
QUESTIONenthalpy change of hydration - answer-when one
mole of a gaseous ion are dissolved in water to make an infinite
dilute solution
QUESTIONwhat are the three standard conditions - answer-
temperature
concentration
pressure
QUESTIONwhat are the units for the three standard conditions -
answer-temperature- 298k
concentration- 1mol dm-3
pressure- 100kpa
QUESTIONwhat is the equation for enthalpy change - answer-
change in internal energy + pressure x change in value
QUESTIONhow o you convert Celsius to kelvin - answer-+ 273
QUESTIONWhat is a catalyst? - answer-a 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
