Homework Problems on this website
This website contains online homework problems for each course topic you will study this semester . You can access all the homework problems for the semester using the menu at the top of the page or on the lower right sidebar. These homework problems are designed to help you learn the course material and practice problem solving skills.
There will be 100 points total available on all the homework assignments this semester. However, they will count out of a total grade of 70 points. This will benefit you. For example, a student who earns 90 total points on the homework throughout the semester will get a 70 out of 70 for their homework grade plus 20 bonus points for the course. A student who earns 63 total points out of the total 100 on the homework throughout the semester will get a 63 out of 70 (or 90%) on homework toward their total course grade.
Guidelines for completing the problems:
- If you are asked to give an answer requiring scientific notation on a homework problem, enter it as follows: Enter 2.45 X 10-5 M as 2.45E-5 M
- Once you start working problems, there will be a table at the top of the assignment telling you how many and what questions you have completed and your score on each. Your completed questions will also be highlighted. This should help you remember your place in case you wish to stop working on the homework and log back in later.
- You can attempt the problems as many times as you wish to get them correct! Caution: You will be graded on your LAST attempt for each question. Therefore, if you get a question right, then rework it and get it wrong, you will earn the grade for the last attempt, which would be wrong.
Organization of problems in each topic
There are five Units in CHEM 151, each containing 2-3 topics for a total of 13 topics during the course of the semester. Each of these topics in CHEM 151 has a homework assignment:
Unit 1 – 20 points
- Essential Ideas- 6 points
- Composition of Substances, Stoichiometry – 7 points
- Acid-Base Titrations – 6 points
Unit 2 – 20 points
- Solutions and Chemical Reactions- 6 points
- Gases – 8 points
- Thermochemistry – 6 points
Unit 3 – 20 points
- Electronic Structure and Periodic Properties of Elements – 10 points
- Chemical Bonding and Molecular Geometry – 10 points
Unit 4 -20 points
- Chemical Equilibria – 8 points
- Acids and Bases – 12 points
Unit 5 – 20 points
- Liquids and Solids – 10 points
- Solutions – 10 points
Each topic has a problem set that can be accessed from the menu at the top or right side of this page.
Your instructor will inform you about the due dates for each homework assignment.
The assignment for each set first lists the learning objectives for the topic (these are from the course syllabus). Below that there are links to the reading in the course textbook OpenStax Chemistry 2e that will help you do the homework problems, along with the problems themselves.
Scoring and grading explanation:
Remember –You will be graded on your LAST attempt for each question. Therefore, if you get a question right, then rework it and get it wrong, you will earn the grade for the last attempt, which would be wrong.
The table at the top of each assignment gives your score and the maximum available score (max score) on each question. These scores are not points. Your goal should be as close as you can to the max score for each question. The points you earn for each assignment will be calculated by taking your total score for the assignment, dividing it by the total max score for the appointment, and multiplying it by the total points for the assignment. See the example below:
Example
A student completed the first assignment (Essential Ideas), which is worth 6 points in the course, and had the following score table:
| Title | Score | Max score |
|---|---|---|
| A.01 | 1 | 1 |
| A.02 | 1 | 1 |
| A.03 | 3 | 3 |
| A.04 | 2 | 2 |
| A.05 | 6 | 6 |
| A.06 | 2 | 2 |
| A.07 | 1 | 1 |
| A.08 | 2 | 2 |
| A.09 | 5 | 7 |
| A.10 | 1 | 1 |
| A.11 | 1 | 1 |
| A.12 | 1 | 1 |
| A.13 | 0 | 1 |
| A.14 | 0 | 1 |
| A.15 | 1 | 1 |
| A.16 | 1 | 1 |
| A.17 | 2 | 2 |
| A.18 | 1 | 1 |
| A.19 | 1 | 1 |
| A.20 | 1 | 1 |
| A.21 | 3 | 5 |
| A.22 | 3 | 4 |
| A.23 | 1 | 4 |
| A.24 | 2 | 2 |
| A.25 | 0 | 1 |
| A.26 | 2 | 2 |
The total in the student score column is 44
The total available max score is 55
The assignment is worth 6 points in the total course grade.
The students score for the assignment would be 44/55 * 6 = 4.8
The student would receive a grade of 4.8 out of the available 6 points for the assignment.
