CHEMICAL INTERACTIONS INVESTIGATION 5: ENERGY TRANSFER

KEY CONCEPTS

• MIXING WATER OF 2 TEMPERATURES RESULTS IN WATER OF AN INTERMEDIATE TEMPERATURE

• When mixing hot water (HIGH KINETIC ENERGY) with cold water (LOW KINETIC ENERGY) WARM WATER (MED. KINETIC ENERGY)

KEY CONCEPTS

• SUBSTANCES HEAT OR COOL AS A RESULT OF ENERGY TRANSFER

• ENERGY TRANSFER = MOVEMENT OF ENERGY FORM 1 PLACE TO ANOTHER. CAN LEAD TO SOMETHING GETTING HOTTER OR COLDER (GAINING OR LOSING ENERGY)

• ENERGY ALWAYS TRANSFERS FROM HIGH KINETIC ENERGY TO LOW KINETIC ENERGY

KEY CONCEPTS

• PARTICLES ARE ALWAYS IN MOTION (KINETIC ENERGY). THE MORE KINETIC ENERGY SOMETHING HAS, THE HOTTER IT IS.

• ENERGY TRANSFERS BETWEEN PARTICLES WHEN THEY COLLIDE. ENERGY TRANSFER THAT RESULTS FROM COLLISIONS IS CALLED CONDUCTION.

• EQUILIBRIUM OCCURS WHEN TEMPERATURE IS UNIFORM

KEY CONCEPTS

• HEAT IS MEASURED IN CALORIES. ONE CALORIE WILL RAISE THE TEMPEREATURE OF 1g OF WATER 1O C.

• TEMPERATURE MEASURES KINETIC ENERGY, WHILE HEAT IS THE MEASURE OF ENERGY TRANSFER, MEASURED IN CALORIES.

• cal = m X ^T • The number of calories

needed to change temperature of a mass of water is equal to the mass of water (in grams) times the temperature change (in degrees Celsius)

KEY CONCEPTS

• ^T = cal / m • The temperature

change of water (in degrees Celsius) is equal to the number of calories divided by the mass of water (in grams)

• TEMPERATURE IS MEASURED IN DEGREES CELSIUS (OC). TEMPERATURE IS THE AVERAGE KINETIC ENERGY OF PARTICLES.

KEY CONCEPTS

• ENERGY IS CONSERVED• The amount of energy

in a system is always the same; no energy is ever created, and no energy is ever destroyed.

• Energy can transfer from one place to another in that system, and it can be transformed from one kind of energy to another kind of energy.

KEY CONCEPTS

• WHEN A SYSTEM IS IN BALANCE, AND THERE IS NO NET ENERGY TRANSFER GOING ON, THE SYSTEM IS IN EQUILIBRIUM.

• AFTER MIXING HOT AND COLD WATER, THE FINAL TEMPERATURE IS ITS EQUILIBRIUM TEMPERATURE.