States of Matter Test Review

Heating Curve for Water What is the explaination of the “flat” segements on the graph? Simulation B A C D

Heating Curve for Water What phase or phases are present at D? Simulation B A C D

Heating Curve for Water What phase or phases are present at A? Simulation B A C D

General Phase Diagram What phase is label B? What phase is label C?

General Phase Diagram What is happening if substance is changing from B to C? From B to D?

Phase Diagram for Water Most substances: –The solid phase is more dense than the liquid phase (solid sinks in liquid) Water: –The solid phase is less dense than the liquid phase (ice floats in liquid water) Occurs because ice expands as it forms. Recall that d = m/v, so since ice takes up more volume it is now less dense than the liquid water.

Boiling Point What is the boiling point of water? What is the boiling point of diethyl ether?

What is the boiling point of chloroform?

Heat of Vaporization and Heat of Fusion Example: What is the amount of energy required to change 32.5 g of liquid Br 2 to gaseous Br 2 if the temperature is held constant? (Molar heat of vaporization for Br 2 is 29.5 kJ/mol) 6.00 kJ

Heat of Vaporization and Heat of Fusion What is heat of vaporization? What is heat of fusion?

Heat of Vaporization and Heat of Fusion Example: What is the amount of energy required to change 5.6 g of solid Benzene (C 6 H 6 ) to liquid Benzene if the temperature is held constant? (Molar heat of fusion for Benzene is 9.84 kJ/mol)

Heat of Vaporization and Heat of Fusion Problems What is the amount of energy required to change 63.2g of ice at 0 o C to water at 0 o C? ( H f = 6.01 kJ/mol)

Specific Heat Capacity –What is Specific Heat Capacity? –What is the formula? Heating Curve

Specific Heat Capacity What is the specific heat capacity of a substance if the surroundings absorb 3503 joules of energy while 46 grams of the substance are heated from 23ºC to 52ºC?

Bond Strength What are the weakest of the intermolecular forces? Why does water have an unusually high boiling point?

Intermolecular Forces Which do you think has the strongest intermolecular forces: a solid, liquid, or gas (all at the same temperature)? Why?

Intermolecular Forces Intermolecular forces determine the phase of a substance. The stronger the intermolecular forces the closer the molecules are attracted to each other; therefore, we have liquids and solids.