Do Now  Write the answers to the following questions on your Daily Organizer:  Glass has a specific heat capacity of while silver has a specific heat capacity of Which one has a greater specific heat capacity? What does that tell you about glass vs. silver?  An 80-gram sample of brass decreases in temperature from 64 °C to 49 °C. What was the heat energy lost by the brass? Brass has a specific heat capacity of J/g/°C.

Today’s Agenda 5 min Do Now 5 min Important Dates 5 min Quiz Review 40 min Quantity of Heat: Step Up 5 min Exit Ticket

Today’s Agenda 5 min Do Now 5 min Important Dates 5 min Quiz Review 40 min Quantity of Heat: Step Up 5 min Exit Ticket

Important Dates  Congrats to 4 th period on highest quiz average!  Grade Notices Today  If missing news project, can complete an extra credit one! These will be due the day before spring break.  Absentee Policy  Lab Notebooks Due Friday  Homework This Week  Valentine’s Day Community Service

Today’s Agenda 5 min Do Now 5 min Important Dates 5 min Quiz Review 40 min Quantity of Heat: Step Up 5 min Exit Ticket

Today’s Agenda 5 min Do Now 5 min Important Dates 5 min Quiz Review 40 min Quantity of Heat: Step Up 5 min Exit Ticket

Calculating Energy  We can find the amount of thermal energy gained or lost by any substance by using its specific heat capacity, the mass of the substance and the temperature change.  Q = mc Δ T  Positive Q: object gained energy – there was an increase in temperature (heated up)  Negative Q: object lost energy – there was a decrease in temperature (cooled down)

Review Problem 1  How much heat is needed to heat 150 grams of silver from 5°C to 78°C? The specific heat capacity of silver is J/g/°C.

Review Problem 2  A sample of water gains 95 Joules of heat when it heats up from 30°C to 50°C. What is the mass of the water sample? The specific heat capacity of water is 4.18 J/g/°C.

Review Problem 3  A 115-gram metal sample loses 164 J of heat when its temperature decreases from 83 °C to 59 °C. What was the specific heat capacity of the metal?

Example  A piece of metal with a specific heat of J/g/°C and an initial temperature of 95°C is placed in a calorimeter that holds 50 g of water. The initial temp of the water is 25°C and the final temp of the system is 40°C. What is the mass of the metal? 1. Start by finding the Q of the water. Use water’s mass, specific heat capacity & change in temp. 2. Set the Q of the metal equal to the -Q of the water! The energy gained by water was lost by the metal so it’s negative! 3. Use this Q to find the mass of the metal. Specific heat capacity & temperatures are given!

Practice Problem 1  A piece of metal with a specific heat capacity of J/g/°C and an initial temperature of 45°C is placed in a calorimeter that holds 60 g of water. The initial temp of the water is 20°C and the final temp of the system is 35°C. What is the mass of the metal?  Hint Start by finding the Q of the water. Set the Q of the metal equal to the -Q of the water! Use this Q to find the mass of the metal.

Practice Problem 2  A 15 gram piece of metal with a temperature of 100°C is placed in a calorimeter that holds 40 g of water. The initial temp of the water is 10°C and the final temp of the system is 50°C. What is the specific heat capacity of the metal?  Hint Start by finding the Q of the water. Set the Q of the metal equal to the -Q of the water! Use this Q to find the specific heat capacity of the metal.

Practice Problem 3  A 25 gram piece of metal with a temperature of 75.0°C is placed in a calorimeter that holds 50.0 g of water. The initial temp of the water is 19.6°C and the final temp of the system is 25.0°C. What is the specific heat capacity of the metal?  Hint Set the Q of the metal equal to the -Q of the water!

Challenge Problem  A 10 gram piece of metal with a specific heat of J/g/°C is placed in a calorimeter that holds 30 g of water. The initial temp of the water is 65°C and the final temp of the system is 20°C. What is the initial temperature of the metal?  Hint This works the same as the other problems except you’re finding the initial temp of the metal!

Complete the two practice problems. When finished, I will check it & give you an exit ticket. After you finish, feel free to work on homework or Capstone Independent Practice

Today’s Agenda 5 min Do Now 5 min Important Dates 5 min Quiz Review 40 min Quantity of Heat: Step Up 5 min Exit Ticket