LARN 137 C35D1
Start the following in class:
1. Write your journal entry on sheets of three holed 8.5 inch by 11 inch ruled paper in your Journal notebook. In the upper right corner white space of each upward facing page, write your hand in number within a circle followed by your name. Each journal entry should either be at least a paragraph of exemplary writing and penmanship concerning a single topic, or be a concept map relating chemistry terms. Begin each day’s paragraph with a topic sentence, follow with explained instances, and close with a focused summary statement.
The required focus topics, J137, for today is
Enthalpy, H, is the term used in chemistry to designate the total energy (a.k.a. heat content) of a chemical system when the total pressure of any gases present in the system is not changing (a.k.a. the system is at constant pressure).
A thermochemical equation is a chemical equation with a statement of the measured enthalpy change for the reaction as recorded in the balanced chemical expression being added to the right side of the chemical equation after leaving a slight space to the right of the last product’s formula.
a. What is the relationship between the SI unit for energy, the joule, J, and the unit of energy called the calorie, cal? [See section 17-1.]
b. Describe a possible method for determining the change in enthalpy for a given reaction, ΔHrx. [You may adapt one of the methods described in the text on pages 511 to 513.]
c. Compare and contrast the terms enthalpy of reaction, ΔHrx, (a.k.a. heat of reaction) and an enthalpy of combustion, ΔHcombustion, (a.k.a. heat of combustion).
2. Go to the web site at http://www.visionlearning.com/reg/login.php, log on into the course+section for which you are registered, and select the module entitled Energy from the module hyperlinks aligned along the left edge of the display. Read this module as if you were creating an SQ5R or PQ5R study guide for it, but are title it: In Class: Energy. Click on the Notes menu item next to the Energy menu item and read and follow the full instructions for what you need to do. When you are finished, click on the Questions Quizzes tab at the top of the module and then click on the The Periodic Table of Elements title, select the best choice response to all the quiz questions and then click on the Score Quiz button. Then examine the feedback on your quiz and reread and study the material pertaining to any items identified as incorrect. Reflect on your responses and retake the quiz as many times as you need for you to fully understand and from that understanding, score 100% on the quiz.
3.a. Use the PQ5R or SQ5R method to prepare study guide for text section 17.2 on Measuring and Expressing Enthalpy Changes, ΔH or go to https://socratic.org/chemistry to research the topics brought up in section 17.2 of your text. Read section 17.2 in your chemistry text, pages 511 through 519 and as you do, create a study guide using the SQ5R or PQ5R method explained in class and on the distributed handout packet. You may record vocabulary entries in the body of your study guide, or you may check them off on the chapter 17 vocabulary list that was distributed as you think about the meanings of the terms and add any notations to the vocabulary list for clarifications sake.
3.b. After you have finished reading the assigned section of the chapter, answer the formative assessment questions and do some formative assessment problems to inform you about the degree of your comprehension and understanding. Assessment questions are printed at the end of the section that you have just read. Reflect on your answers to assure yourself that you have understood the major points in the section that you have just read. Record your responses to questions that are challenging you, so that you can later review what you are learning. If all problems seem easy to you, record the response to the problem that was least easy for you to answer.
Writing in blue or black ink, place your hand in number in a circle followed by your name in the upper right white space of a piece of three holed composition paper that hasn’t been written on. Place the page reference for the problems to be considered to the left of the red marginal line on the first blue line. Centered on the first blue line, write a descriptive title for the learning activity such as Section C1.4 Responses where C1.4 represents Chapter1.section4. Before you write your response to each question or problem listed below, write its designation to the left of the red marginal line as listed below, followed by your response in ink to the right of the marginal line.
If solving the problem entails the use of multiplication or division, show your work by including a ? followed by the unit of the quantity you are solving for, an = sign, followed by the quantity given that has all or part of the dimensions of whatever quantity you are solving for, followed by mathematical operations on all labeled quantities, conversion ratios or comparison ratios that are used to obtain the sought for quantity.
Be aware of the relationship that the amount of heat transferred, q or Q, is equal to the product of the mass of the material being heated or cooled, m, times the specific heat capacity of the material being heated or cooled at constant pressure, Cp, times the change in temperature of the material being heated or cooled, ΔT, to analyze and solve the problem. That is, Q = m · Cp · ΔT. Use dimensional analysis and/or the algebraic definition of heat transferred to the mass of a substance s, ms, Qlost or gained = ms · Cp of s· ΔTs, to help set up the next two problems. Be sure to include the units of each measured quantity, to cancel all units that are both in a numerator and a denominator of multiplied ratios, and to label the resulting units of each calculated value. Also circle and express the calculated result to the proper number of significant figures.
- Study Sample Problem 17.2 on page 513 and then show your work including all conversion ratios for practice problems I17-12 (In chapter 17, problem 12) and I17-13.
- Use dimensional analysis to help set up the next two problems, I17-14 (In chapter 17, problem 14) and I17-15. Be sure to include the units of each measured quantity, to cancel all units that are both in a numerator and a denominator of multiplied ratios, and to label the resulting units of each calculated value. Study Sample Problem 17.3 on page 516 and then show your work including all conversion ratios for practice problems I17-14 (In chapter 17, problem 14) and I17-15. Circle and express the calculated result to the proper number of significant figures.
- In the Section Assessment 17.2 on page 517, read, analyze, describe and explain practice problems I17-16 (In chapter 17, problem 16), I17-17, and I17-20,and then show your work including all conversion ratios for practice problems I17-18 a (show calculation of ΔH), I17-18 b (write the thermochemical equation), and I17-19.
- After you have finished responding to the formative assessment questions and problems, check page R97 of the text and check each of those problems that you can by writing in either a check mark (√) or a correction in green ink. Write down any question that you still have so that you can ask about it in class. In the margin of your notebook page, circle the number of formative assessment questions do not have a suggested response given and check your response with that of your classmates when you come to class.
Recommended for those who have time left in their 45 minute study period, but not required of all:
1. Continue to review the meanings of the words on the chapter 1, chapter 2, chapter 3, chapter 4, chapter 5, chapter 7, chapter 8, chapter 9, chapter 10, chapter 11, chapter 12, chapter 13, chapter 14, chapter 15, chapter 16, and chapter 17 vocabulary lists. Place a – symbol in front of each word that you have to study more,and a change the- to a + symbol in front when you have demonstrated mastery over the word to a study buddy, parent, or friend.
2. Study the Key Concepts given on pages 33, 57, 95, 121, 148, 180, 206, 246, 280, 314, 346, 378, 406, 438, 464, and 498 of the text.