Heating and Changes of State — AQA GCSE Combined Science: Synergy 8465
AQA GCSE Combined Science: Synergy · 8465
Heating and Changes of State
What you need to know
Describe how heating a system increases the internal energy stored by the particles (atoms and molecules) comprising that system.
Explain that an increase in internal energy can either raise the temperature of the system or cause a change of state.
Understand that the energy required for a substance to change state depends on the strength of the forces between its particles, which in turn relates to its atomic structure and bonding.
Recognize that substances with stronger intermolecular forces have higher melting and boiling points.
Explain that during melting, freezing, evaporation, condensation, or sublimation, mass is conserved.
Distinguish these physical changes of state from chemical changes by recognizing that physical changes can be reversed to recover the original material properties.
Define specific heat capacity as the energy required to raise the temperature of one kilogram of a substance by one degree Celsius.
Define specific latent heat as the energy required to change the state of one kilogram of a substance without altering its temperature, distinguishing between the latent heat of fusion (solid to liquid) and vaporization (liquid to vapor).
Interpret heating and cooling graphs that demonstrate changes of state.
Calculate changes in thermal energy using the specific heat capacity equation:
Calculate the energy involved in a change of state using the specific latent heat equation:
E=mL
Carry out practical investigations to determine the specific heat capacity of materials, linking the decrease of one energy store to the increase in temperature and thermal energy stored in another.
