9.2 Measuring Enthalpy Changes Flashcards
1
Q
State the symbol and word equation for energy change.
A
Energy change = mass x specific heat capacity x change in temperature
q = m c 🔺T
2
Q
What is specific heat capacity?
A
The amount of energy required to raise the temperature of 1g of a substance by 1K
3
Q
State the word and symbol equation for enthalpy change.
A
🔺H = q/m
change in enthalpy = energy change / moles
4
Q
Why are experimental values different to data book values?
A
-Heat lost to the surroundings
-Incomplete combustion
-Evaporation of reactants
-Non-standard conditions
5
Q
How do you minimise heat loss and incomplete combustion (in a combustion reaction)?
A
Use draught screens and input oxygen gas
