Structure 1.1 Particulate Nature Of Matter Flashcards
What are the physical and chemical properties dependent on?
The ways in which different atoms combine together
Define an element.
Consists of only one type of atoms
Define a compound.
Consists of atoms of two or more different elements chemically combined together in a fixed ratio
Define a mixture.
A combination of two or more substances that can be separated by physical methods
What distinguishes a homogeneous mixture from a heterogeneous mixture?
Homogeneous mixtures have a uniform composition, while heterogeneous mixtures do not
What is solvation?
The process of surrounding solute particles with solvent particles to form a solution
What is filtration?
A physical separation method to separate solids from liquids or gases using a filter
What is recrystallisation?
A method to purify solid compounds by dissolving them in a suitable solvent and then allowing them to crystallize
What is distillation?
A separation technique that involves heating a liquid to create vapor and then cooling the vapor to create a liquid
What happens to particles in a solid?
Particles vibrate in fixed positions but do not move around
What happens to particles in a liquid?
Particles vibrate, rotate, and move around, with weaker attractive forces than in solids
What happens to particles in a gas?
Particles vibrate, rotate, and move around faster than in liquids, with negligible attractive forces
What determines the state of matter at a given temperature and pressure?
The strength of the forces between the particles (inter-particle forces)
The average kinetic energy of the particles is proportional to what?
The temperature of the system (in K)
What occurs during the heating curve segment a-b?
As solid is heated, vibrational energy of particles increases, so temperature increases
What happens during the melting phase (b-c) of the heating curve?
Energy added is used to break inter-particle forces, so temperature remains constant
What occurs during the boiling phase (d-e) of the heating curve?
Energy is added to break all inter-particle forces to form a gas, with temperature remaining constant
What does the Maxwell-Boltzmann Distribution Curve demonstrate?
The distribution of energies in a sample of gas at the same temperature
What does the maximum point on the Maxwell-Boltzmann graph represent?
The most probable kinetic energy
What does the area under the Maxwell-Boltzmann curve represent?
The total number of molecules in the sample
True or False: The distribution of kinetic energy of molecules changes as temperature changes.
True
Fill in the blank: With a _______ activation energy barrier, a higher proportion of molecules possess sufficient energy to react.
lower
