TEAS Practice Test: Video 5 Answers (25 Questions)

Question 1

A solution with a pH of 3 compared to a solution with a pH of 5 is:

Accepted Answer

100 times more acidic

Answer

The pH scale is logarithmic — each unit difference represents a 10-fold difference in hydrogen ion concentration. A difference of 2 pH units = 10² = 100-fold difference.

Question 2

What is the name for the minimum amount of energy required to start a chemical reaction?

Accepted Answer

Activation energy

Answer

Activation energy is the minimum energy required for reactant molecules to overcome the energy barrier and successfully react to form products.

Question 3

Which of the following is an example of a chemical property?

Accepted Answer

Hydrogen gas is highly flammable

Answer

Flammability describes how a substance reacts with oxygen (a chemical change) — this is a chemical property. The others describe physical properties observed without changing the substance.

Question 4

What is the relationship between pressure and volume of a gas at constant temperature, as described by Boyle's Law?

Accepted Answer

Pressure and volume are inversely proportional (P ∝ 1/V)

Answer

Boyle's Law states that at constant temperature, pressure and volume of a gas are inversely proportional: as pressure increases, volume decreases (P₁V₁ = P₂V₂).

Question 5

Which of Newton's laws states that an object in motion stays in motion unless acted upon by an external force?

Accepted Answer

Newton's First Law (Law of Inertia)

Answer

Newton's First Law (Law of Inertia) states that an object will remain in its current state of motion (rest or constant velocity) unless acted upon by a net external force.