Chemistry Flashcards

Which of the following statements about catalysts is correct?

Answer: A catalyst lowers the activation energy without being consumed

A catalyst provides an alternative reaction pathway with a lower activation energy and is regenerated at the end, so it is not consumed.

According to Le Chatelier's Principle, if the temperature of an exothermic reaction at equilibrium is increased, the equilibrium will shift:

Answer: Toward the reactants

For an exothermic reaction, heat can be considered a product; adding heat (raising temperature) shifts the equilibrium toward the reactants to absorb the excess heat.

The electron configuration of Fe2+ (iron II ion, atomic number 26) is:

Answer: [Ar] 3d6

Fe has [Ar] 3d6 4s2; when Fe2+ forms, the two 4s electrons are removed first, giving [Ar] 3d6.

Which of the following is true about a reaction with a large positive equilibrium constant (K >> 1)?

Answer: The reaction strongly favors products at equilibrium

A large K value (K >> 1) indicates that at equilibrium the concentration of products greatly exceeds the concentration of reactants.

What is the oxidation state of manganese (Mn) in KMnO4?

Answer: +7

In KMnO4, K is +1 and each O is -2 (total -8); to balance, Mn must be +7: (+1) + Mn + (-8) = 0.

Which type of isomerism involves compounds that have the same molecular formula and same connectivity but differ in the spatial arrangement of atoms?

Answer: Stereoisomerism

Stereoisomers have the same molecular formula and connectivity (bonding sequence) but differ in the three-dimensional arrangement of their atoms in space.

Which of the following best describes the colligative property of boiling point elevation?

Answer: It depends only on the number of solute particles in solution

Boiling point elevation is a colligative property, meaning it depends on the number (not the identity) of dissolved solute particles per kilogram of solvent.