CHEM✦
✦
General Chemistry 210
1 MAXE
210 Acid-Base Equilibria · Buffers · Titrations
E R R O R A N A LY S I S · P H · H E N D E R S O N - H A S S E L B A L C H
SCIENCE
Chem 210 Exam 1
SYST E M AT I C & R A N D O M E R R O R · A C I D S & B A S E S · B U F F E R S · T I T R AT I O N S · E Q U I L I B R I U M
C A LCU L AT I O N S
COURSE Chemistry 210 · General Chemistry II EXAM TYPE Unit Examination 1
ACADEMIC YEAR TOTAL QUESTIONS 20 Questions
SUBJECT AREAS Error Analysis · Acid-Base · Buffers · FORMAT Multiple Choice — Select the Single Best
Titrations · pH Calculations Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question.
▸ Content covers: systematic vs. random error, acid-base definitions, strong vs. weak acids/bases, pH/pOH calculations, buffers,
Henderson-Hasselbalch equation, and titrations.
▸ Each question includes the correct answer with a detailed rationale.
SECTION I — COMPREHENSIVE EXAM 1 Questions 1 – 20
1. Systematic error is characterized by:
A. Error due to chance that decreases precision
B. Error that shifts all measurements in a standardized way, decreasing accuracy
C. Error that cannot be detected or corrected
D. Error that affects only a single measurement
CORRECT ANSWER B — Error that shifts all measurements in a standardized way, decreasing accuracy
RATIONALE SYSTEMATIC ERROR shifts all measurements in the same direction — it decreases ACCURACY (closeness to
true value). It results in BIAS and can be discovered and corrected. Examples: inaccurate calibration of
equipment, inaccuracies in a meter, variation in systematic performance with temperature. RANDOM ERROR
(A) is due to chance, decreases PRECISION (reproducibility), and cannot be eliminated but can be reduced by
repeated measurements. PRECISION = how close measurements are to each other. ACCURACY = how close
measurements are to the true value. Systematic error can be identified and corrected; random error is
inherent in all measurements.
✦
General Chemistry 210
1 MAXE
210 Acid-Base Equilibria · Buffers · Titrations
E R R O R A N A LY S I S · P H · H E N D E R S O N - H A S S E L B A L C H
SCIENCE
Chem 210 Exam 1
SYST E M AT I C & R A N D O M E R R O R · A C I D S & B A S E S · B U F F E R S · T I T R AT I O N S · E Q U I L I B R I U M
C A LCU L AT I O N S
COURSE Chemistry 210 · General Chemistry II EXAM TYPE Unit Examination 1
ACADEMIC YEAR TOTAL QUESTIONS 20 Questions
SUBJECT AREAS Error Analysis · Acid-Base · Buffers · FORMAT Multiple Choice — Select the Single Best
Titrations · pH Calculations Answer
EXAMINATION INSTRUCTIONS
▸ Select the single best answer for each question.
▸ Content covers: systematic vs. random error, acid-base definitions, strong vs. weak acids/bases, pH/pOH calculations, buffers,
Henderson-Hasselbalch equation, and titrations.
▸ Each question includes the correct answer with a detailed rationale.
SECTION I — COMPREHENSIVE EXAM 1 Questions 1 – 20
1. Systematic error is characterized by:
A. Error due to chance that decreases precision
B. Error that shifts all measurements in a standardized way, decreasing accuracy
C. Error that cannot be detected or corrected
D. Error that affects only a single measurement
CORRECT ANSWER B — Error that shifts all measurements in a standardized way, decreasing accuracy
RATIONALE SYSTEMATIC ERROR shifts all measurements in the same direction — it decreases ACCURACY (closeness to
true value). It results in BIAS and can be discovered and corrected. Examples: inaccurate calibration of
equipment, inaccuracies in a meter, variation in systematic performance with temperature. RANDOM ERROR
(A) is due to chance, decreases PRECISION (reproducibility), and cannot be eliminated but can be reduced by
repeated measurements. PRECISION = how close measurements are to each other. ACCURACY = how close
measurements are to the true value. Systematic error can be identified and corrected; random error is
inherent in all measurements.
