Question 1

____________________ expresses the margin of uncertainty associated with a measurement.

Accepted Answer

A) Nominal uncertainty 
B) Maximum uncertainty 
C) Relative uncertainty 
D) Minimum uncertainty 
E) Absolute uncertainty 
A) Nominal uncertainty 
B) Maximum uncertainty 
C) Relative uncertainty 
D) Minimum uncertainty 
E) Absolute uncertainty E

Question 2

The distance between two cities is measured and the reported value with ambiguous significant digits is:

Accepted Answer

A) 740.km. 
B) 7)40 F1F1F1S1F1F1F10 102 km. 
C) 740.0 km. 
D) 740 km. 
E) 7)4 F1F1F1S1F1F1F10 102 km. 
A) 740.km. 
B) 7)40 F1F1F1S1F1F1F10 102 km. 
C) 740.0 km. 
D) 740 km. 
E) 7)4 F1F1F1S1F1F1F10 102 km. D

Question 3

The density of a solution is determined using a class A 25-mL volumetric flask and an analytical balance.If the mass of the empty volumetric flask is 26.9872 ± 0.0003 g,the mass of the flask filled with solution is 53.9820 ± 0.0003 g,and the tolerance for the flask is ± 0.03 mL,what is the density of the solution?

Accepted Answer

A) 1)07979 ± 0.00001 g/mL 
B) 1)0798 ± 0.0004 g/mL 
C) 1)0798 ± 0.0003 g/mL 
D) 1)080 ± 0.001 g/mL 
E) 1)0798 ± 0.0005 g/mL 
A) 1)07979 ± 0.00001 g/mL 
B) 1)0798 ± 0.0004 g/mL 
C) 1)0798 ± 0.0003 g/mL 
D) 1)080 ± 0.001 g/mL 
E) 1)0798 ± 0.0005 g/mL D

Question 4

For which measurement has the number of significant digits been incorrectly determined?

Accepted Answer

A) 12.9830 g six significant digits 
B) 1920.3 m five significant digits 
C) 0)0043 g four significant digits 
D) 1)003 L four significant digits 
E) 59.0 km three significant digits 
A) 12.9830 g six significant digits 
B) 1920.3 m five significant digits 
C) 0)0043 g four significant digits 
D) 1)003 L four significant digits 
E) 59.0 km three significant digits

Question 5

Calculate the molar mass of diethyl ether,CH3CH2OCH2CH3.(C = 12.0106 ± 0.0010,H = 1.00798 ± 0.00014,and O = 15.9990 ± 0.0008).

Accepted Answer

74.121 ± 0

Question 6

____________________ cannot be eliminated but it may be reduced by a better experiment.

Accepted Answer

A) User error 
B) Internal error 
C) Systematic error 
D) Random error 
E) Determinate error 
A) User error 
B) Internal error 
C) Systematic error 
D) Random error 
E) Determinate error

Question 7

Calculate the volume of an aquarium that is 73.1 cm long,30.1 cm deep,and 25.44 cm tall.

Accepted Answer

A) 55975 cm3 
B) 55980.cm3 
C) 5)6 F1F1F1S1F1F1F10 104 cm3  
D) 5)60 F1F1F1S1F1F1F10 104 cm3 
E) 55975.9 cm3 
A) 55975 cm3 
B) 55980.cm3 
C) 5)6 F1F1F1S1F1F1F10 104 cm3  
D) 5)60 F1F1F1S1F1F1F10 104 cm3 
E) 55975.9 cm3

Question 8

For the paired statements below,which are TRUE for the detection of an analytical methods systematic error?

Accepted Answer

A) I and II 
B) II and IV 
C) I and IV 
D) II,III,and IV 
E) I,II,III,and IV 
A) I and II 
B) II and IV 
C) I and IV 
D) II,III,and IV 
E) I,II,III,and IV

Question 9

For a fixed absolute uncertainty,as the magnitude of the measurement____________________ ,the percent relative uncertainty____________________ .

Accepted Answer

A) increases;decreases 
B) increases;increases 
C) decreases;decreases 
D) decreases;increases 
E) increases;remains constant 
A) increases;decreases 
B) increases;increases 
C) decreases;decreases 
D) decreases;increases 
E) increases;remains constant

Question 10

An irregular solid with a mass of 25.9863 ± 0.0003 g displaces 20.5 ± 0.2 mL of water.Calculate the density of the solid.

Accepted Answer

The answer of An irregular solid with a mass of...

Question 11

Calculate the error for the molar mass of acetic acid,CH3CO2H.The atomic masses for each element are C = 12.0106 ± 0.0010,H = 1.00798 ± 0.00014,and O = 15.9990 ± 0.0008.

Accepted Answer

A) ± 0.010 g/mol 
B) ± 0.0026 g/mol 
C) ± 0.0013 g/mol 
D) ± 0.0042 g/mol 
E) ± 0.021 g/mol 
A) ± 0.010 g/mol 
B) ± 0.0026 g/mol 
C) ± 0.0013 g/mol 
D) ± 0.0042 g/mol 
E) ± 0.021 g/mol

Question 12

Calculate the mass of a heterogeneous mixture containing 139.32 grams sand,34.99 grams gravel,and 9.372 grams salt.

Accepted Answer

A) 184 g 
B) 183.7 g 
C) 183.68 g 
D) 184.0 g 
E) 183.684 g 
A) 184 g 
B) 183.7 g 
C) 183.68 g 
D) 184.0 g 
E) 183.684 g

Question 13

For significant digits and calculations,the following statements are true,EXCEPT for which one(s)?
I Addition and subtraction―round off the answer according to the number of decimal places in the number with the most decimal places.
II Multiplication and division―the answer is limited to number of digits in the number with the fewest significant digits.
III Logarithms and antilogarithms ―the number of significant figures in the antilogarithm should equal the number of digits in the mantissa.

Accepted Answer

A) I 
B) II 
C) III 
D) I and II 
E) I and III 
A) I 
B) II 
C) III 
D) I and II 
E) I and III

Question 14

____________________ is a consistent error that can be detected and corrected.

Accepted Answer

A) User error 
B) Internal error 
C) Systematic error 
D) Random error 
E) Indeterminate error 
A) User error 
B) Internal error 
C) Systematic error 
D) Random error 
E) Indeterminate error

Question 15

Two students are tasked with determining the milligrams of chloride in a simulated soil sample.Both students extract chloride into aqueous solution and perform triplicate titration with silver nitrate solution and dichlorofluorescein indicator.The students report the following results to their laboratory instructor.   If the accepted value is 36.90 mg chloride/g sample,the laboratory instructor infers that student #2's work exhibits____________________ student #1.

Accepted Answer

A) higher accuracy and higher precision than 
B) higher accuracy and lower precision than 
C) lower accuracy and lower precision than 
D) lower accuracy and higher precision than 
E) results impossible to differentiate from 
A) higher accuracy and higher precision than 
B) higher accuracy and lower precision than 
C) lower accuracy and lower precision than 
D) lower accuracy and higher precision than 
E) results impossible to differentiate from

Question 16

When calculating the uncertainty associated with molar mass,which of the following statements are TRUE? I Uncertainty in the mass of n identical atoms = n F1F1F1S1F1F1F10 (uncertainty in atomic mass for one atom. )
II Uncertainties for different elements are dependent.
III The uncertainty for the sum of the masses of different elements is calculated using the equation   .
IV When summing the masses of different elements,the uncertainties for the mass of different elements are propagated as random errors.

Accepted Answer

A) I,II,and III 
B) I and III 
C) II,III,and IV 
D) I and IV 
E) II and III 
A) I,II,and III 
B) I and III 
C) II,III,and IV 
D) I and IV 
E) II and III

Question 17

Calculate the mass of a concrete slab that is 51.0 cm long,17.34 cm deep,and 6.2 cm tall with a density of 5.3 g/cm3.

Accepted Answer

A) 1)0 F1F1F1S1F1F1F10 103 g 
B) 2)9 F1F1F1S1F1F1F10 104 g 
C) 2)91 F1F1F1S1F1F1F10 104 
D) 1)03 F1F1F1S1F1F1F10 103 g 
E) 2)906 F1F1F1S1F1F1F10 104 g 
A) 1)0 F1F1F1S1F1F1F10 103 g 
B) 2)9 F1F1F1S1F1F1F10 104 g 
C) 2)91 F1F1F1S1F1F1F10 104 
D) 1)03 F1F1F1S1F1F1F10 103 g 
E) 2)906 F1F1F1S1F1F1F10 104 g

Question 18

A mass of approximately 10 grams is measured using weight by difference.If a vial containing calcium carbonate powder has an initial mass of 87.36 ± 0.03 g and a final mass of 76.99 ± 0.03 g,what mass of calcium carbonate was taken?

Accepted Answer

A) 10.37 ± 0.04 g 
B) 10.37 ± 0.03 g 
C) 10.370 ± 0.042 g 
D) 10.370 ± 0.004 g 
E) 10.370 ± 0.005 g 
A) 10.37 ± 0.04 g 
B) 10.37 ± 0.03 g 
C) 10.370 ± 0.042 g 
D) 10.370 ± 0.004 g 
E) 10.370 ± 0.005 g

Question 19

Two students are tasked with determining the milligrams of chloride in a simulated soil sample.Both students extract chloride into aqueous solution and perform triplicate titration with silver nitrate solution and dichlorofluorescein indicator.The students report the following results to their laboratory instructor.   If the accepted value is 36.90 mg chloride/g sample,the laboratory instructor infers that student #1's work exhibits____________________ student #2.

Accepted Answer

A) higher accuracy and higher precision than 
B) higher accuracy and lower precision than 
C) lower accuracy and lower precision than 
D) lower accuracy and higher precision than 
E) results impossible to differentiate from 
A) higher accuracy and higher precision than 
B) higher accuracy and lower precision than 
C) lower accuracy and lower precision than 
D) lower accuracy and higher precision than 
E) results impossible to differentiate from

Question 20

To the correct number of significant digits,what is the molarity of a sodium hydroxide solution when 12.9 grams of NaOH is dissolved in enough water to prepare 0.500 L of solution? (NaOH = 40.00 g/mol)

Accepted Answer

The answer of To the correct number of significant digits,what...

Exam 4: Experimental Error

____________________ expresses the margin of uncertainty associated with a measurement.

The distance between two cities is measured and the reported value with ambiguous significant digits is:

For which measurement has the number of significant digits been incorrectly determined?

Calculate the molar mass of diethyl ether,CH3CH2OCH2CH3.(C = 12.0106 ± 0.0010,H = 1.00798 ± 0.00014,and O = 15.9990 ± 0.0008).

____________________ cannot be eliminated but it may be reduced by a better experiment.

Calculate the volume of an aquarium that is 73.1 cm long,30.1 cm deep,and 25.44 cm tall.

For the paired statements below,which are TRUE for the detection of an analytical methods systematic error?

For a fixed absolute uncertainty,as the magnitude of the measurement____________________ ,the percent relative uncertainty____________________ .

An irregular solid with a mass of 25.9863 ± 0.0003 g displaces 20.5 ± 0.2 mL of water.Calculate the density of the solid.

Calculate the error for the molar mass of acetic acid,CH3CO2H.The atomic masses for each element are C = 12.0106 ± 0.0010,H = 1.00798 ± 0.00014,and O = 15.9990 ± 0.0008.

Calculate the mass of a heterogeneous mixture containing 139.32 grams sand,34.99 grams gravel,and 9.372 grams salt.

____________________ is a consistent error that can be detected and corrected.

Calculate the mass of a concrete slab that is 51.0 cm long,17.34 cm deep,and 6.2 cm tall with a density of 5.3 g/cm3.

A mass of approximately 10 grams is measured using weight by difference.If a vial containing calcium carbonate powder has an initial mass of 87.36 ± 0.03 g and a final mass of 76.99 ± 0.03 g,what mass of calcium carbonate was taken?

To the correct number of significant digits,what is the molarity of a sodium hydroxide solution when 12.9 grams of NaOH is dissolved in enough water to prepare 0.500 L of solution? (NaOH = 40.00 g/mol)

The Analytical Process

Chemical Measurements

Tools of the Trade

Statistics

Quality Assurance and Calibration Methods

Chemical Equilibrium

Let the Titrations Begin

Activity and the Systematic Treatment of Equilibrium

Monoprotic Acid-Base Equilibria

Polyprotic Acid-Base Equilibria

Acid-Base Titrations

Edta Titrations

Advanced Topics in Equilibrium

Fundamentals of Electrochemistry

Electrodes and Potentiometry

Redox Titrations

Electroanalytical Techniques

Fundamentals of Spectrophotometry

Applications of Spectrophotometry

Spectrophotometers

Atomic Spectroscopy

Mass Spectrometry

Introduction to Analytical Separations

Gas Chromatography

High-Performance Liquid Chromatography

Chromatographic Methods and Capillary Electrophoresis

Gravimetric and Combustion Analysis

Sample Preparation

Filters

Calculate the molar mass of diethyl ether,CH₃CH₂OCH₂CH₃.(C = 12.0106 ± 0.0010,H = 1.00798 ± 0.00014,and O = 15.9990 ± 0.0008).

For a fixed absolute uncertainty,as the magnitude of the measurement ,the percent relative uncertainty .

Calculate the error for the molar mass of acetic acid,CH₃CO₂H.The atomic masses for each element are C = 12.0106 ± 0.0010,H = 1.00798 ± 0.00014,and O = 15.9990 ± 0.0008.

Calculate the mass of a concrete slab that is 51.0 cm long,17.34 cm deep,and 6.2 cm tall with a density of 5.3 g/cm³.