Exam buster module 3

Which of the following statements are incorrect regarding Le Chatelier’s Principle?

• If a system in equilibrium has part of its products removed, the equilibrium will shift towards the reactants.

• If a closed system in equilibrium has its pressure increased, the equilibrium will favour the side of the chemical equation with the least molecules

• If the temperature is increased during an exothermic reaction in equilibrium, the reaction will go on to produce more reactants

• a. None of the above.

What is the conjugate acid of HCO₃^-?

• CO₂

• CO₃^2-

• H₂CO₃

• H⁺

The what is the concentration of aqueous KOH that has a pH of 12.7?

• 0.05M

• 5.0 x 10^-3 M

• 2.0 x 10^-13 M

• 0.13M

True or False: a Kc larger than 1 indicates that the equilibrium favours a higher concentration of reactants.

• True

• False

You forget to bring water to uni so you sneak into the chem labs and synthesise 10 moles of H₂O, 2 moles of H₂ and 1 mole of O₂ remain in the bottle at equilibrium. Assuming the temperature and pressure remain constant, what is the Kc of this reaction?

• 100

• 5

• 0.04

• 25

What would the rate law for 2H₂ + O₂ -> 2H₂O be

• k2[H₂]^m [O₂]ⁿ

• k[H₂]² [O₂]

• k[H₂]^m [O₂]ⁿ

• There is not enough information to answer this

Which of the following effects the rate of a reaction?

• The presence of a catalyst

• The time of day

• The season

• All of the above

The following data is from the reaction 2R + S -> T + U. What is the rate law for this?

• Rate = k([R]² + [S])

• Rate = k[2R] [S]

• Rate = k[R]² [S]²

• Rate = k[R]² [S]

Which is true for a galvanic cell?

• Oxidation occurs at the cathode

• Electrons flow from the cathode to the anode

• Electrons are conducted through the salt bridge

• Ecell > 0V

Water reacts with carbon dioxide to produce bicarbonate. You start with 0.5 moles of both reactants and at equilibrium you have 0.4 moles of both. Would the reaction favour the products or reactants? H2O + CO2 -> H2CO3

• Products

• Reactants

• Neither

• There is not enough information to tell