Specific Heat Quantity of energy needed to increase the temperature of one gram of a substance by one degree Celsius/Kelvin Every substance has its own unique specific heat Specific heat of water is 4.184 J/g∙∘K Teacher: Explain background key points (The general what and why.) Students: Listen, then get an opportunity to digest the information in a think-pair-share or write-pair-share. Think-Pair-Share: What is happening to the movement of particles as energy is added? How is particle movement measured?

Specific Heat Equation Q = m c ∆T If Q is positive, the substance absorbed heat. If Q is negative, the substance released heat. Q = Heat (cal or J) m = Mass (g) c = Specific heat (J/g∘K) ∆T = Change in temperature 1 cal = 4.18 J 1000 cal = 1 kcal 0 ∘C = 273 K Teacher: Explains how they break down the problem, how they attack the problem, then carefully explain how they avoid pitfalls/misconceptions. Key points should be posted either on this screen (off to the side), on the board, or on handout. Ask quick low-level questions during to keep students participating (Ex: Is this a positive or a negative?) . After go through example, ask a CFU that gets students to process information. Consider having them write it down or take to a neighbor before answering. (Ex: Is this answer reasonable? Does it make sense given the situation? Why or why not?) Students: Work silently through the problem with the teacher. Answer quick low-level questions. Check For Understanding: It was 45 degrees this morning, now it’s 63. How do you find the temperature change?

Example 1 How it’s done: List your givens and unknowns Rearrange Specific Heat formula to solve for c. Convert units if needed Plug in and solve An unknown substance, with a mass of 50.0 g, is heated from 25 ∘C to 100. ∘C. During the heating process the substance absorbs 750. J of energy. What is the specific heat of the unknown substance in J/g∙∘C? Teacher: Explains how they attack the problem, then carefully explain how they avoid pitfalls/misconceptions. Key points should be posted either on this screen (off to the side), on the board, or on handout. Ask quick low-level questions during to keep students participating (Ex: What equation should I use? What happens next? Is this a positive or a negative?) . After go through example, ask a CFU that gets students to address a misconception. Consider having them write it down or take to a neighbor before answering. (Ex: If I had gotten 2 as the answer, what might I have been confused about?) Students: Work silently through the problem with the teacher. Answer quick low-level questions. Check For Understanding: What does the answer mean? Based on the definition of specific heat, interpret your answer.

Problem 1 (With your partner) 2 min A 21.0 g sample of a substance with a specific heat of 0.449 J/g∘C is heated from 288 K to 434 K. How much heat, in Joules, was absorbed by the substance? Teacher: Posts question. Tells students to work on this problem with their partner for 2 min. Monitors heavily during practice walking around to different pairs. Students: Work through problem with partner on whiteboard or notebook for 2 min. Teacher: Brings it back whole group. Asks them to explain a couple of steps, then checks for a misconception. (1.5 Min only) Check For Understanding: Why does it not matter is specific heat capacity is given in J/g°C or J/gK?

Problem 2 (With your partner) 2 min A student must use 225 g of hot water in a lab procedure. Calculate the amount of heat required to raise the temperature of 225 g of water from 20.0 °C to 100.0 °C. (Specific heat of water is 4.184 J/g°K) Teacher: Posts question. Tells students to work on this problem with their partner for 2 min. Monitors heavily walking around to different pairs. Students: Work through problem with partner on whiteboard or notebook for 2 min. Teacher: Brings it back whole group. Asks them to explain maybe just the first step, the answer, then checks for a misconception. (1.5 Min only)

Problem 3 (Try it yourself first) 2 min A 40.0 g sample of ethanol releases 2952 J as it cools from 50.0 °C. Calculate the final temperature of the ethanol. c = 2.46 J/g°C Teacher: Posts question. Tells students to work on this problem on their own for 1 minute, then for the second minute work with a partner. Students: Work through problem on own then with partner on whiteboard or notebook for Teacher: Monitors everyone while they are working. Quickly gives feedback. Asks students to hold up answers, determines to ask a question about a misconception or not based on where people are. (1 Min only)