IBDP Official Exam Material
FREE Past Paper Questions by Topic
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Topic 11: Measurement and data processing
For both SL and HL students
1. [1 mark]
What combination is the most effective for reducing random and systematic errors?
2. [1 mark]
What information about 2-hydroxybutanoic acid can be inferred through mass spectrometry, MS, infrared spectroscopy, IR, and proton nuclear magnetic resonance spectroscopy, 1H NMR?
3. [1 mark]
A student performed an experiment to find the melting point of sulfur, obtaining 118.0 °C. The literature value is 115.2 °C. What was the percentage error?
A. 118.0-115.2/115.2×100%
B. 115.2/118.0×100%
C. 118.0-115.2/118.0×100%
D. 118.0/115.2×100%
4. [1 mark]
Which compound produces this mass spectrum?
5. [1 mark]
What is the index of hydrogen deficiency (IHD) of this molecule?
Paracetamol (acetaminophen)
A. 3
B. 4
C. 5
D. 6
6. [1 mark]
How many signals are observed in the 1H NMR spectrum of this compound?
7. [1 mark]
What is the uncertainty, in cm3, of this measurement?
A. ±0.01
B. ±0.1
C. ±0.15
D. ±1
8.[2 marks]
Describe two observations that indicate the reaction of lithium with water is exothermic.
9. [2 marks]
Describe a test and the expected result to indicate the presence of carbon–carbon double bonds.
10. [1 mark]
What can be deduced from the mass spectrum of CH3COCH2CH2CH3?
A. The molar mass is 43 g mol−1.
B. The atoms have many isotopes.
C. The most likely bond to break is C–C between carbons 2 and 3.
D. The signal with the largest mass is due to the oxidation of the ketone in the spectrometer.
11. [3 marks]
The following spectrums show the Infrared spectra of propan-1-ol, propanal and propanoic acid. Identify each compound from the spectra given, use absorptions from the range of 1700 cm−1 to 3500 cm−1. Explain the reason for your choice, referring to section 26 of the data booklet.
12a. [1 mark]
Biochemical oxygen demand (BOD) can be determined by the Winkler Method.
Outline what is measured by BOD.
12b [2 marks]
A student dissolved 0.1240 ± 0.0001 g of Na2S2O3 to make 1000.0 ± 0.4 cm3 of solution to use in the Winkler Method.
Determine the percentage uncertainty in the molar concentration.
12c. [1 mark]
A 25.00 cm3 sample of water was treated according to the Winkler Method.
Step I: 2Mn2+ (aq) + O2 (g) + 4OH− (aq) → 2MnO2 (s) + 2H2O (l)
Step II: MnO2 (s) + 2I− (aq) + 4H+ (aq) → Mn2+ (aq) + I2 (aq) + 2H2O (l)
Step III: 2S2O32− (aq) + I2 (aq) → 2I− (aq) + S4O62− (aq)
The iodine produced was titrated with 37.50 cm3 of 5.000 × 10−4 mol dm−3 Na2S2O3.
Calculate the amount, in moles of Na2S2O3 used in the titration.
12d. [1 mark]
Deduce the mole ratio of O2 consumed in step I to S2O32− used in step III.
12e. [2 marks]
Calculate the concentration of dissolved oxygen, in mol dm−3, in the sample.
12f. [1 mark]
The three steps of the Winkler Method are redox reactions.
Deduce the reduction half-equation for step II.
13. [1 mark]
The enthalpy of combustion of a fuel was determined using the calorimeter shown. The final result was lower than the literature value.
Which factors could have contributed to this error?
I. Not all heat from the combustion was transferred to the calorimeter.
II. Incomplete combustion occurred.
III. The temperature probe touched the bottom of the calorimeter.
II. Incomplete combustion occurred.
III. The temperature probe touched the bottom of the calorimeter.
A. I and II only
B. I and III only
C. II and III only
D. I, II and III
14. [1 mark]
Burette readings for a titration are shown.
What is the mean titre?
A. 11.1 cm3 ± 0.1 cm3
B. 11.15 cm3 ± 0.05 cm3
C. 11.2 cm3 ± 0.05 cm3
D. 11.2 cm3 ± 0.1 cm3
15. [1 mark]
What can be deduced from the infrared (IR) spectrum of a compound?
A. Number of hydrogens
B. Number of hydrogen environments
C. Bonds present
D. Molar mass
16. [1 mark]
Which is correct for the spectra of organic compounds?
A. Mass spectroscopy provides information about bond vibrations.
B. 1H NMR spectroscopy provides the values of carbon–hydrogen bond lengths.
C. Infrared spectroscopy provides the number of hydrogen atoms.
D. Mass spectroscopy provides information about the structure.
17. [1 mark]
What is the ratio of areas under each signal in the 1H NMR spectrum of 2-methylbutane?
A. 6 : 1 : 2 : 3
B. 3 : 3 : 1 : 5
C. 6 : 1 : 5
D. 3 : 3 : 1 : 2 : 3
18. [1 mark]
What are the absolute and percentage uncertainties for the change in mass?
Initial mass: 22.35 ±0.05 g
Final mass: 42.35 ±0.05 g
19. [1 mark]
The enthalpy of combustion of ethanol is determined by heating a known mass of tap water in a glass beaker with a flame of burning ethanol.
Which will lead to the greatest error in the final result?
A. Assuming the density of tap water is 1.0 g cm−3
B. Assuming all the energy from the combustion will heat the water
C. Assuming the specific heat capacity of the tap water is 4.18 J g−1 K−1
D. Assuming the specific heat capacity of the beaker is negligible
20. [1 mark]
Which value of q, in J, has the correct number of significant figures?
q = mcΔT
where m = 2.500 g, c = 4.18 J g−1 K−1 and ΔT = 0.60 K.
A. 6
B. 6.3
C. 6.27
D. 6.270
If you need the markscheme, including the examiners' reports for each question, and more exam and teaching materials on this topic, contact me through the contact page