HSC Chemistry Module 8: Applying Chemical Ideas Practice Questions

Question 6

During a gravimetric analysis investigation, you found that the mass of a sample containing KCl weighed 0.628g. This solution was treated with AgNO₃ and the subsequent AgCl precipitate weighed 1.345g. Calculate the percentage of K that was in the original sample (4 marks)

(L1.3: Conduct investigations and/or process data involving: Gravimetric analysis, Precipitation titration)

Question 7

A mixture containing KCl and NaBR only is analyzed using the Mohr method. A 0.3172g sample is dissolved in 50mL of water and titrated to Ag₂CrO₄ end point, requiring 35.85mL of 0.1120 M AgNO₃. A blank titration requires 0.71mL of titrant to reach the same endpoint. Report the %w/w KCl in the sample. (5 marks)

Question sourced from LibreTexts

(L1.3: Conduct investigations and/or process data involving: Gravimetric analysis, Precipitation titration)

Question 8

Describe the steps used to determine the concentration of a solution using colorimetry (5 marks). 

(L1.4: Conduct investigations and/or process data to determine the concentration of coloured species and/or metal ions in aqueous solution, including but not limited to, the use of: Colourimetry, UV spectrophotometry, Atomic absorption spectroscopy)

Question 9

The following graph has two peaks, labelled ‘a’ and ‘b’. Answer the following questions using the graph below. (3 marks)

Graph sourced from Chou et. al. (2017)

a) What does the first peak represent?

b) What does the second peak represent? 

c) How would you use this graph to quantify the sun protection factor (SPF) of a new sunscreen brand? 

(L1.4: Conduct investigations and/or process data to determine the concentration of coloured species and/or metal ions in aqueous solution, including but not limited to, the use of: Colourimetry, UV spectrophotometry, Atomic absorption spectroscopy)

Question 10

Draw a diagram depicting how atomic absorption spectroscopy works. Explain the principle behind this procedure. (4 marks) 

(L1.4: Conduct investigations and/or process data to determine the concentration of coloured species and/or metal ions in aqueous solution, including but not limited to, the use of: Colourimetry, UV spectrophotometry, Atomic absorption spectroscopy)

Analysis of Organic Substances

Question 11

Explain how you used bromine water to test for the presence of a carbon-carbon single or double bond. Include relevant structural equation(s). (3 marks)

(L2.1: Conduct qualitative investigations to test for the presence of organic molecules of the following functional groups: Carbon-carbon double bonds, Hydroxyl groups, Carboxylic acids)

Question 12

Susan used sodium to identify primary, secondary and tertiary hydroxyl groups. Here are her results: 

Identify which samples contain either primary, secondary and tertiary hydroxyl groups (3 marks). 

(L2.1: Conduct qualitative investigations to test for the presence of organic molecules of the following functional groups: Carbon-carbon double bonds, Hydroxyl groups, Carboxylic acids)

Question 13

What is the importance of calcium hydroxide when testing for the presence of carboxylic acid using sodium carbonate? (3 marks)

(L2.1: Conduct qualitative investigations to test for the presence of organic molecules of the following functional groups: Carbon-carbon double bonds, Hydroxyl groups, Carboxylic acids)

Question 14

Identify the organic compound using the 1H NMR graph below. (3 marks)

Image sourced from eBioChemicals

(L2.2: Investigate the processes used to analyse the structure of simple organic compounds addressed in the course, including but not limited to: Proton and carbon-13 NMR, Mass spectroscopy, Infrared spectroscopy)

Question 15

Identify the structural formula of the organic compound illustrated in the ¹³C graph below. (3 marks)

Image sourced from Chemical Book

(L2.2: Investigate the processes used to analyse the structure of simple organic compounds addressed in the course, including but not limited to: Proton and carbon-13 NMR, Mass spectroscopy, Infrared spectroscopy)

Question 16

Identify the structural formula using the following mass spectroscopy graph. (3 marks)

(L2.2: Investigate the processes used to analyse the structure of simple organic compounds addressed in the course, including but not limited to: Proton and carbon-13 NMR, Mass spectroscopy, Infrared spectroscopy)

Question 17

Identify the organic compound using the infrared spectrum graph below. (3 marks) 

(L2.2: Investigate the processes used to analyse the structure of simple organic compounds addressed in the course, including but not limited to: Proton and carbon-13 NMR, Mass spectroscopy, Infrared spectroscopy)

Chemical Synthesis and Design

Question 18

Consider the Haber process, whereby atmospheric nitrogen and hydrogen are converted synthetically into ammonia as described in the equilibrium equation below: 

Evaluate the importance of monitoring the availability of reagents and reaction conditions in this process with relation to yield and purity. (7 marks). 

(L3.1: Evaluate the factors that need to be considered when designing a chemical synthesis process, including but not limited to: Availability of reagents, Reaction conditions, Yield and purity, Industrial uses, Environmental, social and economic issues)

Question 19

Describe examples of industrial uses of products that are made from a named chemical synthesis process. (4 marks) 

(L3.1: Evaluate the factors that need to be considered when designing a chemical synthesis process, including but not limited to: Availability of reagents, Reaction conditions, Yield and purity, Industrial uses, Environmental, social and economic issues)

Question 20

Evaluate the importance of considering environmental, social and economic factors when designing a chemical synthesis process. Include a specific example of a chemical synthesis process and its relevant chemical equations. (7 marks)

(L3.1: Evaluate the factors that need to be considered when designing a chemical synthesis process, including but not limited to: Availability of reagents, Reaction conditions, Yield and purity, Industrial uses, Environmental, social and economic issues)