Heating Curve Poster Work Time

• You have 30 minutes to finish your poster with your partner.

• Make sure that you answer all of the questions on the bottom of the sheet.

• Finalize your poster by adding color and pen.• Check that you have all the required elements

with the rubric on the back.

Think-Pair-ShareThink: How could you calculate how much energy was released from the Cheeto? What information do you think would be important to know?Pair: discuss your thoughts with your partner.Share: share your ideas with the class.

End

Lecture 7.4: Calorimetry I

Learning TargetsLT7.5 – Using calorimetry data, I can utilize my knowledge of temperature change, latent heats, and specific heats to calculate the amount of heat transferred for a reaction.

How do we calculate heat energy?

I. Specific Heat Capacity

A. Specific heat capacity = amount of energy required to raise 1 g of a substance 1 ˚C.

B. Symbol: cC. Units: J/g˚CD. Every substance and every phase of every

substance has a different specific heat capacity.

II. Calculating q

A. Heat energy = (mass)(specific heat)(temp change)q = mcΔTq – heat energym – mass of objectc – specific heat capacityΔT = final temp – initial temp

Example (I Do): If m = 10.0g, c = 1.0 J/g˚C, final temp = 25 ˚C and initial temp = 10 ˚C, what is q?

Variables Equations Work

Example (I Do): What is the energy change in Joules that occurs when 40.0 g of Fe is heated from 25 ˚C to 37 ˚C? Iron has a specific heat of 0.46 J/g˚CVariables Equations Work

Example (We Do): If 4000 J of energy is absorbed when 225 g of Fe is heated from 87 ˚C, what is the final temperature of the iron? (c = 0.46 J/g˚C)Variables Equations Work

Whiteboard Question #1

If m = 10.0 g, c = 2.0 J/g˚C, and ΔT = 20 ˚C, what is q?

Whiteboard Question #2

How much energy is absorbed by 20g of gold if it is heated from 0 ˚C to its melting point at 1064 ˚C? The specific heat of gold is 25.6 J/g ˚C.

Whiteboard Question #3

You need 71 Joules of energy to raise the temperature of 34.0 g of NH3 from 23.0 ˚C to 24.0 ˚C. Calculate the specific heat capacity (c) of ammonia.

Whiteboard Question #4

7,150 Joules of heat is added to 150g of water at a temperature of 31.0 ˚C. What is the final temperature of the water? (c = 4.2 J/g˚C)

Independent Practice• Begin working independently on the

Calorimetry 1-2-3-10 practice.• 10 points on this exercise and your exit ticket

are your ticket out the door today.

Closing Time• Homework:– HW7.2 due date extended to Weds.– Additional tutoring today/tomorrow after

school and lunch.

• Unit 7 Test Thursday/Friday.