HSC 2020 Chemistry Exam Answers - Questions - 1 - 10

This video covers the answer to all multiple choice questions 1 - 10 of the 2020 NSW HSC Chemistry Exam.

0:00 Intro
0:06 Q1 - What is the function of the magnetic field in a mass spectrometer?
0:59 Q2 - Which indicator in the table would be best for distinguishing between a face cleanser (pH = 5.0) and a soap (pH = 9.0)?
2:07 Q3 - Which of the following compounds is the most basic?
3:32 Q4 - Which pair of compounds would be difficult to distinguish using infrared spectroscopy?
5:41 Q5 - A 13C NMR spectrum is shown. Which compound gives rise to this spectrum?
8:51 Q6 - The structure of a compound is shown. What is the preferred IUPAC name of this compound?
9:51 Q7 - The structures of four isomers are shown. Which statement is correct?
11:42 Q8 - A weak base is titrated with 1.0 mol L−1 aqueous HCl. The pH curve is shown. At which pH value would the solution be most effective as a buffer?
12:23 Q9 - Which compound reacts readily with sodium hydrogen carbonate?
13:05 Q10 - Equimolar solutions of NaCl(aq), NH4Cl(aq) and NaCH3COO(aq) were prepared. In which of the following are these salt solutions listed from least to most acidic?

Q1 What is the function of the magnetic field in a mass spectrometer?
A. It detects the mass of the particles.
B. It deflects the stream of charged particles.
C. It excites electrons to higher energy levels.
D. It produces a stream of electrons that bombards the sample.

Q2 Which indicator in the table would be best for distinguishing between a face cleanser (pH = 5.0) and a soap (pH = 9.0)?

Q3 Which of the following compounds is the most basic?
A. Ethane
B. Ethanol
C. Ethanamine
D. Ethyl ethanoate

Q4 Which pair of compounds would be difficult to distinguish using infrared spectroscopy?
A. Butane and propane
B. Ethane and propan-1-ol
C. Propanol and propanoic acid
D. Methanamine and propanone

Q5 A 13C NMR spectrum is shown. Which compound gives rise to this spectrum?
A. chloroethane
B. 1-chloropropane
C. 1,2-dichloroethane
D. 1,2-dichloropropane

Q6 The structure of a compound is shown. What is the preferred IUPAC name of this compound?
A. 1,1,1-tribromo-2-fluoropropan-3-ol
B. 2-fluoro-3,3,3-tribromopropan-1-ol
C. 2-fluoro-1,1,1-tribromopropan-3-ol
D. 3,3,3-tribromo-2-fluoropropan-1-ol

Q7 The structures of four isomers are shown. Which statement is correct?
A. Compounds 1 and 2 are chain isomers.
B. Compounds 1 and 4 are chain isomers.
C. Compounds 2 and 3 are functional group isomers.
D. Compounds 2 and 4 are positional isomers.

Q8 A weak base is titrated with 1.0 mol L−1 aqueous HCl. The pH curve is shown. At which pH value would the solution be most effective as a buffer?
A. 5
B. 7
C. 8
D. 9

Q9 Which compound reacts readily with sodium hydrogen carbonate?

Q10 Equimolar solutions of NaCl(aq), NH4Cl(aq) and NaCH3COO(aq) were prepared. In which of the following are these salt solutions listed from least to most acidic?
A. NaCl(aq), NH4Cl(aq), NaCH3COO(aq)
B. NaCl(aq), NaCHCOO(aq3), NH4Cl(aq)
C. NH4Cl(aq), NaCl(aq), NaCH3COO(aq)
D. NaCH3COO(aq), NaCl(aq), NH4Cl(aq)