chem

How does the nutritional Calorie compare with the calorie?

1 kcal= 1000 calories

How does the kinetic energy of particles vary as a function of temperature?

It is directly proportional to the temperature.

Explain the difference between the processes of melting and freezing?

Melting requires an input of energy to convert a solid to a liquid. Freezing occurs when a liquid becomes a solid and energy is released

What is the relationship between the Calorie and a kilocalorie?

One nutritional Calorie is equal to 1 kilocalorie.

Describe the information that a phase diagram supplies?

The combinations of temperature and pressure under which a given substance exists as a solid, liquid, and gas.

Critical Point

The critical point is the temperature and pressure above which a substance cannot exist as a liquid.

The enthalpy change for a reaction, ΔH, is negative. What does this indicate about the chemical potential energy of the system before and after the reaction?

The system's chemical potential energy is less after the reaction than before the reaction.

What happens to the temperature of boiling water when heat is added to the boiling water?

The temperature stays the same.

Triple Point

The triple point is the temperature and pressure at which the three phases of a substance can coexist.

As the temperature of a gas increases the average speed of its molecules.......

increases

The heat energy released when liquid water becomes ice is measured in units of

joules

When the particles of a solid gain enough kinetic energy to break their ordered arrangement and slip past one another, which process is occurring?

melting

is an exothermic reaction positive or negative?

negative

is an endothermic reaction positive or negative?

positive

What quantity has the units J/(g · °C)?

specific heat