9TH EDITION EXAM QUESTIONS AND CORRECT
ANSWERS (verified answers) Q & A 2026 /INSTANT
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1. In quantitative chemical analysis, the term “accuracy” refers to:
A. Closeness of results to each other
B. Closeness of a measured value to the true value
C. Number of significant figures used
D. Precision of repeated measurements
Answer: B
Accuracy is the degree to which a measured value agrees with the true or
accepted value.
2. Precision in analytical chemistry is best described as:
A. Agreement between measured and true value
B. Reproducibility of results under unchanged conditions
C. Absence of systematic error
D. High accuracy only
Answer: B
Precision refers to how close repeated measurements are to each other, regardless
of correctness.
3. A systematic error affects results by:
A. Increasing random variation
B. Causing consistent deviation in one direction
,C. Occurring unpredictably
D. Cancelling out on averaging
Answer: B
Systematic errors consistently bias results either high or low.
4. Random errors are primarily caused by:
A. Instrument calibration faults
B. Human bias
C. Unpredictable fluctuations in measurement
D. Incorrect theory
Answer: C
Random errors arise from uncontrolled and unpredictable variations.
5. The number of significant figures in 0.004560 is:
A. 2
B. 3
C. 4
D. 5
Answer: C
Trailing zeros after a decimal and after a non-zero digit are significant.
6. Which of the following is a primary standard substance?
A. HCl
B. NaOH
C. KHP (Potassium hydrogen phthalate)
D. NH₄OH
,Answer: C
KHP is stable, pure, and suitable for preparing standard solutions.
7. Standard solution refers to:
A. A solution of unknown concentration
B. A solution with accurately known concentration
C. Any diluted solution
D. A saturated solution
Answer: B
A standard solution has precisely known concentration.
8. Titration is used to determine:
A. Density of solution
B. Volume of solution
C. Concentration of an unknown solution
D. Temperature of reaction
Answer: C
Titration determines unknown concentration via reaction with a standard solution.
9. The endpoint in titration is:
A. Theoretical completion point
B. Point where indicator changes color
C. Start of reaction
D. Equivalence of moles
Answer: B
The endpoint is observed via indicator change.
, 10. The equivalence point is:
A. When indicator changes color
B. When acid and base volumes are equal
C. When stoichiometric amounts react completely
D. When titration starts
Answer: C
It is the theoretical point of exact reaction completion.
11. A burette is used to measure:
A. Approximate volumes
B. Fixed volume only
C. Accurate variable volumes
D. Mass of liquid
Answer: C
A burette delivers precise variable volumes during titration.
12. The main purpose of an indicator in titration is to:
A. Increase reaction speed
B. Show completion of reaction
C. Measure concentration
D. Stabilize pH
Answer: B
Indicators signal endpoint via color change.
13. A mole is defined as:
A. 6.02 × 10²³ particles
B. Mass of substance