2021 Year 12 Chemistry Alternate Task

Which one of the following would be classed as a weak, diprotic acid?

• H₂SO₄ (aq)

• H₂CO₃ (aq)

• HCOOH (aq)

• CH₂(OH)CH₂OH (aq)

A student is told that an unlabelled solution may contain one or more nitrate salts of Mg2+, Pb2+ and/or Ba2+.

They are required to determine which cation/s are present in the solution and are provided with several solid ionic compounds for this analysis.

Which compound below, when added to water, would form an effective reagent for the first step in this analysis?

• silver chloride

• potassium chloride

• lithium sulfate

• copper (II) sulfate

The structure of a compound is shown above.

What is the preferred IUPAC name of this compound?

• 2-hydroxyheptan-5-one

• 5-oxo-heptan-2-ol

• heptan-2-ol-5-one

• 6-hydroxyheptan-3-one

An infrared spectrum is shown above.

Which compound gives rise to this spectrum?

• hexan-1-ol

• hexan-2-one

• hexanal

• hexanoic acid

“X” is prepared from a reaction of “Y” and “Z” as described in the following equation.

Y_(g) + Z_(g) <-> 3X _(g)

Which set of conditions would optimise the rate at which X _(g) is initially produced?

• High pressure, high temperature.

• Low pressure, low temperature.

• High pressure, low temperature.

• Low pressure, high temperature.

The curve above shows the change in pH vs the volume of solution added from a burette during an acid-base titration.

Which alternative identifies the type of solution present in the conical flask and burette during this titration.

• Solution in conical flask: Strong base

  Solution in burette: Strong acid

• Solution in conical flask: Weak base

  Solution in burette: Strong acid

• Solution in conical flask: Weak acid

  Solution in burette: Weak base

• Solution in conical flask: Strong acid

  Solution in burette: Weak base

How many signals does the compound shown above produce in its ¹H NMR and ¹³C NMR spectra?

• ¹H NMR spectra: 5

  ¹³C NMR spectra: 6

• ¹H NMR spectra: 6

  ¹³C NMR spectra: 6

• ¹H NMR spectra: 6

  ¹³C NMR spectra: 7

• ¹H NMR spectra: 5

  ¹³C NMR spectra: 7

Hydrogen can be produced from methane. The equation for the reaction is shown.

2H₂O_(g) + CH_4(g) <-> CO_2(g) + 4H_2(g)

What is the correct equilibrium expression (K_eq) for this reaction?

• 
• 
• 
• 

As the temperature of a particular reaction was increased, the rate of the reaction increased.

Which statement best explains why this occurred?

• The product molecules collided more frequently.

• The product molecules collided with the correct orientation.

• The reactant molecules collided with greater energy per collision.

• The reactant molecules collided less frequently.

The graph above shows the progress of an equilibrium reaction.

Which row of the table correctly identifies what is happening at t₁, t₂ and t₃?

• t₁: at equilibrium

  t₂: reactants added

  t₃: new equilibrium position

• t₁: at equilibrium

  t₂: products added

  t₃: new equilibrium position

• t₁: no reaction occurring

  t₂: reaction proceeding

  t₃: reaction occurring

• t₁: only forward reaction occurring

  t₂: forward and reverse reactions occurring

  t₃: only reverse reaction occurring