which of the following colligative properties refers to the elevation of the boiling point of a solution

ATI TEAS 7

TEAS 7 science practice questions

1. Which of the following colligative properties refers to the elevation of the boiling point of a solution?

A. Freezing point depression
B. Vapor pressure lowering
C. Osmotic pressure
D. Boiling point elevation

Correct answer: D

Rationale: The correct answer is D, 'Boiling point elevation.' Boiling point elevation is a colligative property that describes the increase in the boiling point of a solvent when a non-volatile solute is added to it. This occurs because the presence of solute particles in the solvent lowers the vapor pressure of the solution, requiring a higher temperature to reach the same vapor pressure as the pure solvent. Choices A, B, and C are incorrect. Freezing point depression refers to the lowering of the freezing point of a solution, vapor pressure lowering is the reduction in vapor pressure due to the presence of solute particles, and osmotic pressure is the pressure required to prevent the flow of solvent molecules across a semipermeable membrane in osmosis.

2. Why do Neon (Ne) and Helium (He) belong to Group 18 (Noble Gases)?

A. Electromagnetism
B. Gravity
C. Strong nuclear force
D. Weak nuclear force

Correct answer: A

Rationale: Neon (Ne) and Helium (He) belong to Group 18 (Noble Gases) because they have complete and stable outer electron shells. The stability of these outer electron shells is due to the balance of attractive forces between the positively charged protons in the nucleus and the negatively charged electrons in the outer shell. This balance is maintained by the electromagnetic force, which is responsible for holding atoms together and determining their chemical properties. Gravity (Choice B) is a force of attraction between objects with mass and is not responsible for the stability of electron shells. The strong nuclear force (Choice C) and weak nuclear force (Choice D) are forces that act within the nucleus of an atom and are not directly related to the stability of outer electron shells in determining an element's group in the periodic table.

3. What is the function of the epiglottis?

A. Produces saliva
B. Senses taste
C. Prevents food from entering the windpipe
D. Filters blood

Correct answer: C

Rationale: The epiglottis is a flap of cartilage located at the base of the tongue that covers the opening of the windpipe (trachea) during swallowing to prevent food and liquids from entering the airway. This action ensures that food and liquids are directed to the esophagus and down into the stomach, rather than entering the respiratory system, which could lead to choking or aspiration pneumonia. Options A, B, and D are incorrect as they describe functions of other structures in the body that are not related to the role of the epiglottis.

4. When a person pushes a box across the floor, which of the following forces is NOT doing work?

A. The person's pushing force
B. The normal force from the floor
C. The gravitational force on the box
D. The frictional force between the box and the floor

Correct answer: B

Rationale: The normal force from the floor is perpendicular to the direction of motion of the box, so it does not contribute to the work being done. Work is only done by forces acting in the direction of motion of an object. In this case, the normal force is acting at a right angle to the motion, hence it does not perform any work on the box. The person's pushing force, the gravitational force, and the frictional force are all acting in the direction of motion of the box, so they contribute to the work being done in moving the box across the floor.

5. A 10 kg box rests on a frictionless surface. A horizontal force of 20 N is applied to the box. What is the box's acceleration?

A. 0.5 m/sÂ²
B. 1 m/sÂ²
C. 2 m/sÂ²
D. 10 m/sÂ²

Correct answer: B

Rationale: The acceleration of an object is given by the formula $a = \frac{F}{m}$, where $F$ is the net force acting on the object and $m$ is the mass of the object. In this case, the net force acting on the box is 20 N, and the mass of the box is 10 kg. Plugging these values into the formula, we get $a = \frac{20}{10} = 2$ m/sÂ².