polarity is based on what
Logo

Nursing Elites

HESI A2

Chemistry HESI A2 Quizlet

1. What determines polarity in a molecule?

Correct answer: C

Rationale: Polarity in a molecule is determined by the difference in electronegativity between the atoms forming the bond. The greater the difference in electronegativity, the more polar the bond and molecule become. This difference leads to an uneven distribution of electron density within the bond, creating partial positive and negative charges on the atoms involved. Choices A, B, and D are incorrect. Bond length and strength do not determine polarity, and molecular weight is not directly related to the polarity of a molecule.

2. What type of intermolecular force is a dipole attraction?

Correct answer: B

Rationale: A dipole attraction is considered a weak intermolecular force. It occurs between molecules with permanent dipoles, where the positive end of one molecule is attracted to the negative end of another molecule. While dipole-dipole interactions are stronger than dispersion forces, they are weaker than hydrogen bonding or ion-dipole interactions. Therefore, the correct answer is 'Weak.' Choices A, C, and D are incorrect because dipole attractions are not classified as strong, medium, or very strong intermolecular forces, but rather fall into the category of weak intermolecular forces.

3. How many electron pairs are shared to form a double covalent bond?

Correct answer: B

Rationale: The correct answer is B. In a double covalent bond, two pairs of electrons are shared between two atoms. This sharing of two electron pairs results in a stronger bond compared to a single covalent bond where only one pair of electrons is shared. Choice A is incorrect because a single covalent bond involves the sharing of one pair of electrons. Choices C and D are incorrect as they do not represent the correct number of electron pairs shared in a double covalent bond.

4. What are the products of the combustion of a hydrocarbon?

Correct answer: A

Rationale: When a hydrocarbon undergoes combustion, it reacts with oxygen to produce water and carbon dioxide as the main products. The general chemical equation for the combustion of a hydrocarbon is hydrocarbon + oxygen → carbon dioxide + water. Therefore, the correct answer is 'Water and carbon dioxide.' Choices B, C, and D are incorrect because water and carbon dioxide are the primary products of hydrocarbon combustion, not water and oxygen, hydrogen and carbon monoxide, or carbon dioxide and oxygen.

5. How does increasing the concentration of reactants affect a chemical reaction?

Correct answer: B

Rationale: Increasing the concentration of reactants leads to more reactant particles being available, which, in turn, increases the likelihood of successful collisions between particles. This higher frequency of collisions results in a higher reaction rate. Therefore, option B, 'Increases the reaction rate,' is the correct answer. Choice A, 'Decreases the reaction rate,' is incorrect because higher reactant concentration usually speeds up the reaction. Choice C, 'Stops the reaction,' is incorrect as increasing concentration promotes more collisions, enhancing the reaction. Choice D, 'Has no effect,' is incorrect because changing reactant concentration directly impacts the reaction rate in most cases.

Similar Questions

What is the oxidation state of the sulfur atom in sulfuric acid H2SO4?
What is the correct electron configuration for lithium?
What form of radiation is composed of electrons traveling at around 16,000 km/sec?
Which chemical reaction involves the formation of a single product from two or more reactants?
What is the term used when an atom gains one or more electrons?

Access More Features

HESI A2 Basic
$99/ 30 days

  • 3,000 Questions with answers
  • 30 days access

HESI A2 Premium
$149.99/ 90 days

  • Actual HESI A2 Questions
  • 3,000 questions with answers
  • 90 days access

Other Courses