States, Boiling Point, Melting Point, and Solubility

Solid GasLiquid

Defining States of Matter

● States of matter are defined by whether they hold SHAPE and VOLUME

Element (Au) Compound (NaCl) Mixture (Milk, Salt, etc)

ALL KEEP THE SAME SHAPE AND VOLUME = Solids

Particle View of a Solid

● Particles in a solid are PACKED CLOSELY together and they are in a FIXED POSITION.

Particles vibrate in place

Liquids

● Liquids – has definite VOLUME but no defined SHAPE

100 ml

Particle View of a Liquid

● Packed CLOSELY (like a solid), but move FREELY around each other (must stay in contact).

Gases● Gases - do NOT have definite SHAPE or VOLUME.

Bromine gas fills up the entire volume of the container.

Particle view of a Gas

● Particles can MOVE FREELY and will either fill up or squeeze into available space.

Task

● Draw a diagram of

● A) Gas particles

● B) Liquid particles

● C) Solid particles

Changes in States of Matter

● Thermal Energy – heat energy.

● More thermal energy = More particle movement

Changing States

Solid GasLiquid

Increase Thermal Energy (Heat up)

Decrease Thermal Energy (Cool off)

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Boi

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Melting point

● Melting - change from solid to liquid

● Melting point - SPECIFIC temperature when melting occurs.

● Each pure substance has a SPECIFIC melting point.● Examples:

● M.P. of Water = 0°C (32°F)

● M.P. of Nitrogen = -209.9 °C (-345.81998 °F)

● M.P. of Silver = 961.93 °C (1763.474 °F)

● M.P. of Carbon = 3500.0 °C (6332.0 °F)

Melting Point

● Particles of a solid vibrate so fast that they break free from their fixed positions.

Solid Liquid

Increasing Thermal Energy

Melting point

Vaporization

● Vaporization – change from liquid to gas

● Vaporization happens when particles in a liquid gain enough energy to form a gas.

GasLiquid

Increasing Thermal Energy

Boiling point

Two Kinds of Vaporization

● Evaporation – vaporization that takes place only on the surface of the liquid

● Boiling – when a liquid changes to a gas BELOW its surface as well as above.

Boiling Point

● Boiling Point – temperature at which a liquid boils

● Each pure substance has a SPECIFIC boiling point.

● Examples:

● B.P. of Water = 100°C (212°F)

● B.P. of Nitrogen = -195.79 °C (-320.42 °F)

● B.P. of Silver = 2162 °C (3924 °F)

● B.P. of Carbon = 4027 °C (7281 °F)

Boiling Point

Solid GasLiquid

Increase Thermal Energy (Heat up)

Decrease Thermal Energy (Cool off)

Melting & Boiling Point

Solid GasLiquid

Increase Thermal Energy (Heat up)

Decrease Thermal Energy (Cool off)

Melting Point

Boiling Point Gas turns back into a

liquid at its boiling point

because it’s moving in the

OTHER DIRECTION.

Metal becomes a

liquid just above its

melting point.

Boiling Point

Solid GasLiquid

Increase Thermal Energy (Heat up)

Decrease Thermal Energy (Cool off)

● Particles move the least under melting point (as a solid).

● Tin is a metal. Describe the movement of particles AFTER boiling point of Tin.

● The higher the boiling point, the more energy required to boil!Which one

requires the most

energy to boil?

Boiling Point and Melting Point

Melting point

Boiling point

Solubility

● Maximum amount of a substance that can be dissolved in a liquid (at a specific temperature).

● Soluble means it will dissolve. Insoluble means it will NOT dissolve.

● Stirring SPEEDS UP the dissolution process because you are increasing the movement and the energy of the particles.

The War of Insolubility!

Solubility can change…

● Increased Temp = Increased Solubility

● Different substances have different solubility curves

NaCl Dissolving in H2O