Title: PhysChem section

Q: What happens to the pH when carbon dioxide dissolves in water?
- Carbon dioxide does not dissolve in water.
- The pH increases.
- The pH decreases.
- The pH remains unchanged.
A: The pH decreases.

Q: Which of the following statements about carbon dioxide are true?
- Carbon dioxide is poisonous.
- Carbon dioxide is denser than air.
- Carbon dioxide is flammable.
- Carbon dioxide smells of burnt coal.
A: Carbon dioxide is denser than air.

Q: Which of the following statements about carbon monoxide are true?
- Carbon monoxide is poisonous.
- Carbon monoxide is denser than air.
- Carbon monoxide is flammable.
- Carbon monoxide smells of burnt coal. (CO is an odourless gas.)
A: Carbon monoxide is poisonous.; Carbon monoxide is flammable.

Q: The catalytic converter in modern cars converts carbon monoxide, nitrogen oxides (NO_x) and hydrocarbons to what?
- carbon dioxide, oxygen and nitrogen
- carbon, ammonia and water
- carbon dioxide, water and nitrate
- carbon dioxide, nitrogen and water
A: carbon dioxide, nitrogen and water

Q: How many protons, neutrons and electrons does a hydrogen atom consist of?
- one proton, one neutron, one electron
- one proton, no neutrons, one electron
- two protons, no neutrons, two electrons
- no proton, one neutron, one electron
A: one proton, no neutrons, one electron

Q: Light of which colour has the highest energy?
- yellow
- red
- green
A: green

Q: The absorption of visible light is primarily due to which process?
- The excitation of molecular rotations
- The excitation of molecular vibrations
- The excitation of electrons into higher energy levels
- The expulsion of electrons from atoms
A: The excitation of electrons into higher energy levels

Q: Which of the following hazards apply to boric acid?
- toxic
- teratogenic (i.e., harmful to the foetus)
- carcinogenic (i.e, cancer-causing)
- flammable
A: teratogenic (i.e., harmful to the foetus)

Q: Bromocresol green has a pKa of 4.7.  What functional group(s) is responsible for its acidity?
- sulfonic acid
- aromatic bromo substituents
- phenolic hydroxyl groups
- ammonium groups
A: phenolic hydroxyl groups

Q: Iodine generally is:
- an oxidising agent
- a reducing agent
- neither reducing nor oxidising
A: an oxidising agent

Q: How does addition of the iron chloride catalyst change the parameters of the Arrhenius equation?
- The rate constant k increases because the activation energy E decreases
- The rate constant k increases because the activation energy E increases
- The rate constant k increases because the the reaction temperature T decreases
- The rate constant k does not change.
A: The rate constant k increases because the activation energy E decreases

Q: What are the roles of potassium permanganate and hydrogen peroxide in the titration reaction (multiple correct answers)?
- Permanganate acts as an oxidising agent.
- Permanganate is being oxidised.
- Permanganate is being reduced.
- Hydrogen peroxide acts as an oxidising agent.
- Hydrogen peroxide is being oxidised.
- Hydrogen peroxide is being reduced.
A: Permanganate acts as an oxidising agent.; Permanganate is being reduced.; Hydrogen peroxide is being oxidised.

Q: What are the bubbles that form when pipetting hydrogen peroxide solutions?
- Oxygen
- Water vapour
- Hydrogen
- Carbon dioxide
A: Oxygen

Q: One cubic centimetre (cm^3) equals how many millilitres (mL)?
- 1
- 1.043
- 0.1
- 100
A: 1

Q: Disposable nitrile gloves are generally more resistant to polar solvents than to non-polar ones. How would you classify toluene?
- Toluene is comparatively polar (similar to methanol).
- Toluene is of medium polarity (similar to acetone).
- Toluene is comparatively non-polar (similar to hexane).
A: Toluene is comparatively non-polar (similar to hexane).

Q: At the point in the titration where [H_3PO_4] = [H_2PO_4^– ], the slope of the titration curve ...
- ... is at a minimum.
- ... at a maximum.
- ... exactly 1.
- ... mathematically undefined.
A: ... is at a minimum.

Q: How will addition of sodium hydroxide to phosphoric acid affect the temperature of the acid solution?
- The temperature will increase.
- The temperature will not be affected.
- The temperature will decrease.
A: The temperature will increase.

Q: What is the boiling point of carbon tetrachloride (in degrees Celsius)?
A: 76 (± 5)

Q: What is the boiling point of toluene?
A: 111 (± 3)

Q: What is the pH of a 0.1 mol L^-1 solution of sodium hydroxide (assume complete dissociation of NaOH)?
A: 13 (± 0.05)

Q: Which of the following hazards are associated with acetonitrile?
- flammable
- carcinogenic
- harmful
- explosive
A: flammable; harmful

Q: An average human cell has a diameter of about 10 μm. How much smaller (approximately) is the diameter of Fullerene-C60?
- 10000
- 1000
- 100
- 100000
- one million
A: 10000

Q: Under what conditions does iron hexacyanoferrate evolve hydrogen cyanide gas?
- Acidic conditions
- Alkaline conditions
- Reductive conditions
- Oxidative conditions
A: Acidic conditions

Q: What should be the concentration ratio of the supporting electrolyte and the analyte in electrochemical measurements?
- The electrolyte concentration should be much greater than the analyte concentration.
- The analyte concentration should be much greater than the electrolyte concentration.
- Both concentrations should be approximately the same.
- Depends on the type of electrochemical cell.
A: The electrolyte concentration should be much greater than the analyte concentration.

Q: Octadecene vapours are harmful if inhaled. What is the boiling point of 1-octadecene?
A: 315 (± 10)

Q: What is the formal oxidation state of selenium in CdSe?
A: -2

Q: What is the function of triphenylphosphine in the preparation of CdSe nanocrystals?
- reducing agent
- oxidising agent
- surfactant
- catalyst
A: reducing agent

Q: What pH range do you expect the solutions of HAuCl_4 and tri-sodium citrate to fall in?
- HAuCl4: acidic, trisodium citrate: alkaline
- HAuCl4: acidic, trisodium citrate: neutral
- HAuCl4: neutral, trisodium citrate: neutral
- HAuCl4: neutral, trisodium citrate: alkaline
- HAuCl4: alkaline, trisodium citrate: alkaline
A: HAuCl4: acidic, trisodium citrate: alkaline

Q: Extran is the trade name of a widely used class of industrial/laboratory detergents.  Which hazard(s) are associated with this chemical?
- Corrosive (alkaline)
- Corrosive (acidic)
- Skin irritant
- explosive
A: Corrosive (alkaline); Skin irritant

Q: The pKa values of 8-hydroxyquinoline are 9.9 (protonation equilibrium of the hydroxy group) and 5.1 (protonation equilibrium of the ring nitrogen).  At pH 6, the majority of the molecules is in what protonation state?
- Both nitrogen and oxygen are protonated.
- Nitrogen is deprotonated, oxygen is protonated.
- Nitrogen is protonated, oxygen is deprotonated.
- Both nitrogen and oxygen are deprotonated.
A: Nitrogen is deprotonated, oxygen is protonated.

Q: A solution containing 1 mmol/L each of compounds 1 and 2 is analysed by UV/vis spectroscopy at the wavelength of 510 nm.  The absorbances of the individual compounds at 1 mmol/L are A1 and_ A2.  What is the absorbance of the mixture?
- A1 x A2
- A1 + A2
- A1 - A2
- A1 or A2, whichever is greater
A: A1 + A2