Exam 1 Review - CHE 131 Exam 1, Fall 2016 Wednesday...

Exam 1 Review
Be sure to bring the following:
• Stony Brook ID card
• 2 or more #2 pencils and a good eraser
• Scientific calculator with spare batteries
DO NOT BRING a text, notes, or any aids to taking the exam
All electronic devices must be powered off and out of sight
Violations may result in a course grade of F and a report to
the Academic Judiciary .
No one will be permitted to leave the exam before 9:30 PM.
CHE 131 Exam 1, Fall 2016
Wednesday September 21 st , 8:45 – 10:15 PM
Solar ID Room
000000000 – 110490342
Javits 100 Main Floor
110490343 – 110786975 Javits 100 Balcony
110786976 – 110918185
Frey 100
110918186 – 110987389
Javits 102
110987390 – 111045848
Javits 110
111045849 – 111089091
Harriman Hall 137
111089092 – 111115332
Humanities 1003
111115333 – 111158531
Humanities 1006
111158532 – 111184244
Javits 101
111184245 – 111204566
Javits 103
111204567 – 999999999
Javits 109
CHE 131 Exam 1, Fall 2016
Wednesday September 21 st , 8:45 – 10:15 PM
• You are given a periodic table
• All multiple choice.
• 25 questions + 1 bonus (4 points each)
• Some conceptual, some numerical
• A few have multiple steps and take time
• Point value same regardless of difficulty!
• Budget your time carefully
• Includes everything up to and including lecture #8
• The past semesters have different lecture schedule so
the practice exams covers more materials.
• You should review relevant topics (chapter 1-3) in
practice exams
Jiangyong Jia; Che 131, Fall 2015
Info for Exam #1

Chemical Changes vs. Physical Change
Chemical Properties vs. Physical Properties
Intensive property vs. Extensive property
Changes and properties Matter Classification
MATTER
(Diff. States)
Can it be physically
separated?
Homogeneous
Mixture
(solution)
Heterogeneous
Mixture Compound Element
MIXTURE PURE SUBSTANCE
yes no
Can it be chemically
decomposed?
no yes
Is the composition
uniform?
no yes
Good accuracy
Good precision
Poor accuracy
Good precision
Poor accuracy
Poor precision
Accuracy vs. Precision
}
Accuracy can be true of an individual measurement or the average
of several
}
Precision requires several measurements before anything can be
said about it
Suppose a length measurement: = 4.670 cm, 4.675 cm, 4.678 cm,
Truth is 4.95 cm.
Significant Figures
}
Counting Sig Figs
◦ Count all numbers EXCEPT:
Leading zeros -- 0.00 25
Trailing zeros without
a decimal point -- 2,500
1. 23.50
2. 402
3. 5,280
4. 0.080
4 sig figs
3 sig figs
3 sig figs
2 sig figs
Exact Numbers do not limit
e # of sig figs.
Counting numbers: 12 students
Exact conversions: 1 m = 100 cm
“1” in any conversion: 1 in = 2.54 cm
Examples

Calculating with significant figures
}
Calculating with Sig Figs
◦ Multiply/Divide - The # with the fewest sig figs
determines the # of sig figs in the answer.
(13.91g/cm
3
)(23.3cm
3
) = 324.103g
324 g
4 SF 3 SF
3 SF
Rounding
0.1-0.4 round to 0
0.5-0.9 round to 1
3.75 mL
+ 4.1 mL
7.85 mL
Calculating with significant figures
}
Calculating with Sig Figs (con’t)
◦ Add/Subtract - The # with the lowest decimal value
determines the place of the last sig fig in the answer.
3.75 mL
+ 4.1