Enthalpy Changes (AQA A-Level Chemistry): Quizzes
📚Quizzes
Practise the questions
10 questions from this quiz
ShowHide
Practise the questions
10 questions from this quiz
Under what condition is enthalpy change () measured?
Under what condition is enthalpy change () measured?
Constant pressure
What is the sign of for an endothermic reaction?
What is the sign of for an endothermic reaction?
Positive
What is the sign of for an exothermic reaction?
What is the sign of for an exothermic reaction?
Negative
In an exothermic reaction, how do products compare to reactants in terms of energy?
In an exothermic reaction, how do products compare to reactants in terms of energy?
Products have less energy
What is the standard temperature for measuring enthalpy changes?
What is the standard temperature for measuring enthalpy changes?
298 K (25°C)
What is the standard pressure for measuring enthalpy changes?
What is the standard pressure for measuring enthalpy changes?
100 kPa
What does standard enthalpy of formation () represent?
What does standard enthalpy of formation () represent?
Formation of 1 mole of compound from elements
What is the enthalpy of formation for elements in their standard states?
What is the enthalpy of formation for elements in their standard states?
Zero
What does standard enthalpy of combustion () represent?
What does standard enthalpy of combustion () represent?
Burning 1 mole completely in oxygen
If of methane is -890 kJ/mol, what is for combustion of 2 moles?
If of methane is -890 kJ/mol, what is for combustion of 2 moles?
-1780 kJ/mol