Thermochemistry
Which transition metal would you predict to form a colored compound when bonded with chloride ions based on its electronic configuration?
[Zirconium(Zr)Kr5 s² ,4d²]
[Titanium (Ti), Ar4 s² ,3d² ]
[Zinc (Zn), Ar4 s² ,3d¹⁰ ]
[Scandium (Sc), Ar4 s² ,3d¹ ]
Given that both reactants and products are gases, how would changing pressure influence the sign and magnitude of enthalpy change during a chemical reaction?
Decreasing pressure causes systems absorbing heat becoming more endothermic as they expand.
Changes in pressure induce Le Chatelier's principle shifts yielding varied amounts released/absorbed heats based phase transitions involved.
Increasing pressure decreases volume thus releases heat making reactions more exothermic.
Pressure changes do not affect enthalpy directly since it's a state function independent from work done on/by gas expansion/contraction.
In an endothermic reaction where ΔH° is positive, what could be inferred about the bond strengths of reactants compared to products?
Reactant bonds are stronger than product bonds
Product bonds are stronger than reactant bonds
Reactant and product bonds have equal strength
Bond strength comparison cannot be determined by ΔH° alone
Given an endothermic reaction with a positive ΔH value, which scenario would result in an increased magnitude for ΔH if all other conditions remain constant?
Conducting the reaction at higher temperatures
Decreasing the external pressure on the system
Increasing reactant concentrations
Adding a catalyst
In an exothermic reaction, how does the enthalpy of the products compare to the reactants?
It is equal to that of reactants.
It is higher than that of reactants.
Entropy determines this relationship, not enthalpy.
It is lower than that of reactants.
What effect does adding a catalyst have on a chemical equilibrium position?
It halts any further progression toward reaching an equilibrium state in either direction.
Shifts equilibrium toward reactant formation as it stabilizes intermediate forms.
No effect; it accelerates both forward and reverse reactions equally without shifting equilibrium.
Shifts equilibrium to favor product formation since reactions occur faster.
Which everyday process is an example of an exothermic reaction where the enthalpy change (ΔH) is negative?
Dissolving sugar in water to make syrup.
Freezing water to make ice cubes.
Boiling water to cook pasta.
Melting chocolate for a fondue.

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When a chemical equation is balanced properly according to stoichiometry, what does it imply about the corresponding enthalpies?
Coefficients indicate temperature changes during reaction.
The coefficients reflect molar ratios used in calculating enthalpies.
Enthalpies are determined by reversible or irreversible nature only.
Balancing equations eliminates any changes in enthalpies.
In consideration of quantum mechanics, how might electron delocalization within conjugate systems influence resonance stabilization and subsequently affect calculated reaction enthalpy?
Creates high-energy intermediates, increasing overall reaction enthalpy.
Increases stability, leading to lower than expected calculated reaction enthalpies.
Reduces potential barrier height without influencing reaction enthalpy calculations.
Imposes no significant effect since electron configuration remains relatively static.
Considerations During Photosynthetic Plants Converting Sunlight Energies Into Sugars Their Chloroplasts The Cholese Process Overall Is -
Exothermic
Endothermic
Adiabatic
Isothermic