Test Prep Test Prep Certifications OAT Questions & Answers

• Question 41:

  Which of the answer choices represents a group containing a metal, metalloid and nonmetal elements?

  A. Calcium, Nickel, Carbon

  B. Potassium, Neon, Hydrogen

  C. Lithium, Hydrogen, Silicon

  D. Hydrogen, Oxygen, Silicon

  E. Cesium, Boron, Silicon

  Correct Answer: C

  Periodic trends such as ionization energy, electronegativity, atomic radii, basicity etc. are very important to know as they are commonly tested topics. It is also important to recognize the groups in the periodic table such as the Metals, Non- metals and Metalloids. Only choice (C) provides an element from each group. Lithium (Metal), Hydrogen (Non-metal) and Silicon (Metalloid).

• Question 42:

  What is the pH of 0.001M NaOH solution?

  A. 11

  B. 3

  C. 13

  D. 8

  E. 5

  Correct Answer: A

  Because this is a strong base, we automatically assume concentration of [OH−] = 0.001 = 1.0 × 10−3.

  pOH = −log[OH−] = −log[1.0 × 10−3] = −(−3) = 3 pH = 14 − pOH pH = 14 − 3 = 11

  Be sure to be familiar and able to calculate logs. You will be expected to without a calculator. The above problem was an easy conversion (likely to be seen), but you may provided with more harder ones (ex. [OH −] = 3.4 × 10−3)

• Question 43:

  Which of the following series of elements lists an alkaline earth metal, transition metal, nonmetal and noble gas in that respective order?

  A. Mg, Cu, Zn, I

  B. Mg, Ne, Fe, H

  C. He, F, Fe, Mg

  D. Ca, Fe, N, Ne

  E. Br, H, Ca, Mg

  Correct Answer: D

• Question 44:

  Which of the following holds the greatest bond energy?

  A. HCl

  B. O2

  C. Br2

  D. CN

  E. OH

  Correct Answer: D

  In general, triple bonds > double bonds > single bonds in bond energies. CN is linked via a triple bond: C N

• Question 45:

  What is the molecular geometry of BF3?

  A. Linear

  B. Tetrahedral

  C. Trigonal Planar

  D. T-shaped

  E. Square planar

  Correct Answer: C

• Question 46:

  The coexistence of solid, liquid and gas in thermodynamic equilibrium is called:

  A. Melting point

  B. Triple point

  C. Condensation point

  D. Equilibrium point

  E. Coexisting point

  Correct Answer: B

  This is indeed the definition of what a triple point is.

• Question 47:

  Solution A has a pH of 2, whereas Solution B has a pH for 4.5. How much more acidic is Solution A over Solution B?

  A. 10x more acidic

  B. 2.25x more acidic

  C. 100x more acidic

  D. 315x more acidic

  E. 1000x more acidic

  Correct Answer: D

  There is a difference of pH of 2.5. We know that difference is acidity can be calculated with 10x, where x = difference in acidity.

  102.5 is a number you cannot calculate in your head without a calculator. But you know 102 = 100, and 103 = 1000. Thus, you know the answer relies between 100 and 1000, and there is one answer choice that is in between those 2 values (but not the actual values).

• Question 48:

  Which of the following elements do not belong with the others?

  A. Boron

  B. Aluminium

  C. Silicon

  D. Germanium

  E. Arsenic

  Correct Answer: B

  The answer choices are all metalloids except Aluminium.

• Question 49:

  If Keq < 1, then which of the following is correct in regards to the equilibrium mixture?

  A. Contains less reactants than products.

  B. Contains less products than reactants.

  C. There is equal amounts of products and reactants.

  D. Contain more products than reactants.

  E. None of the above.

  Correct Answer: B

  If Keq > 1, then the equilibrium reaction will contain less reactants than products.

• Question 50:

  According to Charles' law:

  A. Volume is proportional to temperature.

  B. Volume is inversely proportional to temperature.

  C. Volume is proportional to pressure.

  D. Volume is inversely proportional to pressure.

  E. Volume is proportional to moles.

  Correct Answer: A