Potential CHM 113 Final Exam Questions
Following are 15 questions from Extra Credit Discussion Board #4. The first 12 are among those that had the
most “likes.” Because there were many quality questions submitted toward the end of the submission
window, and subsequently did not get a lot of likes, I have also chosen 3 questions just because I like them.
The questions are arranged in the order of the chapters that we covered.
You will see FOUR of these questions on the Final Exam.
NOTE: In choosing questions, I used the following criteria
• The question had to be understandable and accurate. If a question did not make sense or had a wrong
solution, it was not considered, regardless of how many likes it had.
• If there were multiple questions that were very similar, I chose one of them based on which was the best
written and which one had the most likes.
• If a question was identical to a question from one of my exams, it was not considered, regardless of how many
likes it had.
(8 likes)
(Chapter 1) True or False. A pure substance can be separated into simpler substances through physical
methods such as filtration or distillation.
A. True
B. False
Answer: B (False)
Explanation: A pure substance is composed of one particle type and cannot be separated into simpler substances by a
physical process. Physical processes/methods can separate mixtures, not pure substances. Filtration and distillation are
physical methods, which is why they separate mixtures not pure substances. Pure substances are broken down and
separated into simpler substances by chemical processes such as chemical reactions.
(11 likes)
(Chapter 1) How many significant figures are in 656.980?
A. 5
B. 6
C. 4
D. 3
Answer: B (6)
Explanation: B is the CORRECT answer because all digits (6, 5, 6, 9, 8, and 0) are significant. We count the zero at the
end because trailing zeros to the right of the decimal ARE significant. Not to mention, all non-zero digits (like 6, 5, 9, and
8) are significant.
, (6 likes)
(Chapter 5) A system performs 94 kJ of work on its surroundings and loses 43 kJ of heat. What is the value
of ΔE (in kJ) for the system?
A. -137 kJ
B. +51 kJ
C. -51 kJ
D. _137 kJ
Answer: A (-137 kJ)
Explanation: This question uses the equations ΔE = q + w. The answer is -137 kJ because -43 - 97 = -137 kJ.
(13 likes)
(Chapter 7) Which of the following elements has the largest atomic radius?
A. magnesium
B. arsenic
C. barium
D. strontium
Answer: C (barium)
Explanation: When considering the atomic radius trends on the periodic table, recall that the radius increases from the
top to the bottom and from the right to the left. An easy way to envision this is to think of two snowmen: one is stood
upright and has the bottom as the largest snowball, and one is laying down with the largest snowball being on the left.
For solving this problem, process of elimination automatically shows you that arsenic is in the upper right part of the
table and is probably not the answer. Magnesium is fairly high up in the table and probably not the answer either.
However, barium and strontium are both near the bottom left. Determining the larger radius between the two is done
by considering which is lower, as moving down an entire period means adding on another shell of electrons which
greatly expands the atom. Therefore, barium has the largest atomic radius.
Following are 15 questions from Extra Credit Discussion Board #4. The first 12 are among those that had the
most “likes.” Because there were many quality questions submitted toward the end of the submission
window, and subsequently did not get a lot of likes, I have also chosen 3 questions just because I like them.
The questions are arranged in the order of the chapters that we covered.
You will see FOUR of these questions on the Final Exam.
NOTE: In choosing questions, I used the following criteria
• The question had to be understandable and accurate. If a question did not make sense or had a wrong
solution, it was not considered, regardless of how many likes it had.
• If there were multiple questions that were very similar, I chose one of them based on which was the best
written and which one had the most likes.
• If a question was identical to a question from one of my exams, it was not considered, regardless of how many
likes it had.
(8 likes)
(Chapter 1) True or False. A pure substance can be separated into simpler substances through physical
methods such as filtration or distillation.
A. True
B. False
Answer: B (False)
Explanation: A pure substance is composed of one particle type and cannot be separated into simpler substances by a
physical process. Physical processes/methods can separate mixtures, not pure substances. Filtration and distillation are
physical methods, which is why they separate mixtures not pure substances. Pure substances are broken down and
separated into simpler substances by chemical processes such as chemical reactions.
(11 likes)
(Chapter 1) How many significant figures are in 656.980?
A. 5
B. 6
C. 4
D. 3
Answer: B (6)
Explanation: B is the CORRECT answer because all digits (6, 5, 6, 9, 8, and 0) are significant. We count the zero at the
end because trailing zeros to the right of the decimal ARE significant. Not to mention, all non-zero digits (like 6, 5, 9, and
8) are significant.
, (6 likes)
(Chapter 5) A system performs 94 kJ of work on its surroundings and loses 43 kJ of heat. What is the value
of ΔE (in kJ) for the system?
A. -137 kJ
B. +51 kJ
C. -51 kJ
D. _137 kJ
Answer: A (-137 kJ)
Explanation: This question uses the equations ΔE = q + w. The answer is -137 kJ because -43 - 97 = -137 kJ.
(13 likes)
(Chapter 7) Which of the following elements has the largest atomic radius?
A. magnesium
B. arsenic
C. barium
D. strontium
Answer: C (barium)
Explanation: When considering the atomic radius trends on the periodic table, recall that the radius increases from the
top to the bottom and from the right to the left. An easy way to envision this is to think of two snowmen: one is stood
upright and has the bottom as the largest snowball, and one is laying down with the largest snowball being on the left.
For solving this problem, process of elimination automatically shows you that arsenic is in the upper right part of the
table and is probably not the answer. Magnesium is fairly high up in the table and probably not the answer either.
However, barium and strontium are both near the bottom left. Determining the larger radius between the two is done
by considering which is lower, as moving down an entire period means adding on another shell of electrons which
greatly expands the atom. Therefore, barium has the largest atomic radius.
