OAT General Chemistry 5

Question 1

Which of the following is the correct electron configuration for Fe²⁺?

Accepted Answer

[Ar] 3d⁶

Answer

Fe is [Ar]3d⁶4s²; Fe²⁺ loses the two 4s electrons first, giving [Ar]3d⁶.

Question 2

The Nernst equation is used to calculate:

Accepted Answer

Cell potential under non-standard conditions

Answer

The Nernst equation relates cell potential to concentration: E = E° - (RT/nF)ln(Q).

Question 3

Which of the following statements about enthalpy (ΔH) is correct?

Accepted Answer

ΔH of formation for an element in its standard state is zero

Answer

By definition, the standard enthalpy of formation for any element in its standard state is zero.

Question 4

In the reaction 2H2O2 → 2H2O + O2, hydrogen peroxide acts as:

Accepted Answer

Both an oxidizing and reducing agent

Answer

H2O2 undergoes disproportionation: one molecule is oxidized (O goes from -1 to 0) and another is reduced (O goes from -1 to -2).

Question 5

Which of the following acids is considered a strong acid?

Accepted Answer

Nitric acid (HNO3)

Answer

Nitric acid (HNO3) is one of the seven strong acids that dissociate completely in aqueous solution.

OAT - Optometry Admission Test Practice Test