Objectives: Provided with necessary materials and instruction, the students will be able to:

1. Define heat, specific heat, latent heat of fusion and latent heat of vaporization.2. Discuss the effect of heat on the temperature of a substance and the phase of the substance.3. Apply the law of conservation of energy by solving calorimetry problems.4. Calculate the amount of heat added or removed from a substance in order to change its temperature.5. Calculate the amount of heat added or removed from a substance in order to change its state.

In usually warm climates that experience an occasional hard freeze, fruit growers will spray the fruit trees with water, hoping that a layer of ice will form on the fruit. Why is this advantageous?

Heat is the energy that is transferred between a system and its environment because of the temperature difference between them.

One Calorie of food is equivalent to one kilocalorie of energy.

The amount of heat is needed to change the temperature is given by Q = mcTwhere:Q = heat added or removedm = mass of the substancec = specific heat T = change in temperature

The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.

Energy ConservationQabsorbed = -Qreleased

Phase change

Q = mLwhere Q = heatm = mass of substanceL = latent heat Q = mLf for freezing or meltingQ = mLv for condensation or vaporization

In usually warm climates that experience an occasional hard freeze, fruit growers will spray the fruit trees with water, hoping that a layer of ice will form on the fruit. Why is this advantageous?

The phase change from water into ice requires a RELEASE of energy. The matter must cool down. This energy is what goes to protect the plant.

When liquid water touches the plant and the air is below freezing, the water freezes instead of the plant. When there is liquid water on the plant, the temperature cannot drop below freezing - the water all has to freeze first. So if farmers spray their plants throughout the time of frost danger, the plants will not freeze.

Climate near big bodies of water is usually more moderate than the ones that are far from bodies of water. Why?

Large bodies of water such as seas, oceans and large lakes take longer to heat up and cool down than the greater landmass. As a result, areas in the vicinity of large bodies of water remain cooler in summer and warmer in winter.