what is the boiling point of water in c

HESI A2

HESI A2 Chemistry

1. What is the boiling point of water in °C?

A. 90°C
B. 100°C
C. 95°C
D. 80°C

Correct answer: B

Rationale: The correct answer is 100°C. The boiling point of water in Celsius is 100°C, which is standard at sea level. This is the temperature at which water changes from a liquid to a gas phase under standard atmospheric pressure. Choice A (90°C), Choice C (95°C), and Choice D (80°C) are incorrect because they do not represent the standard boiling point of water at sea level.

2. What type of chemical reaction involves the reaction of a compound with oxygen?

A. Decomposition
B. Synthesis
C. Combustion
D. Single replacement

Correct answer: C

Rationale: The correct answer is C: Combustion. A combustion reaction is characterized by a compound reacting with oxygen. During this process, heat and light are often produced as energy is released in the form of heat. Combustion is a common type of reaction involving organic compounds, like hydrocarbons, reacting with oxygen to produce carbon dioxide and water. Choices A, B, and D are incorrect because decomposition involves a compound breaking down into simpler substances, synthesis involves the combination of two or more substances to form a more complex one, and single replacement involves an element replacing another element in a compound.

3. Which of the following elements is a halogen?

A. Oxygen
B. Fluorine
C. Sodium
D. Carbon

Correct answer: B

Rationale: The correct answer is 'Fluorine' (Choice B) as it is a halogen. Halogens are a group of elements that include fluorine, chlorine, bromine, iodine, and astatine. They are highly reactive nonmetals located in Group 17 of the periodic table. Oxygen (Choice A) is a nonmetal but not a halogen. Sodium (Choice C) is a metal, and Carbon (Choice D) is a nonmetal, neither of which belong to the halogen group.

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

A. Strong
B. Weak
C. Medium
D. Very strong

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.

5. In the solid state, you would expect a nonmetal to be _________.

A. brittle
B. lustrous
C. malleable
D. conductive

Correct answer: A

Rationale: In the solid state, you would expect a nonmetal to be brittle. Nonmetals generally lack the malleability and ductility of metals, which makes them prone to being brittle and easily fractured under stress. This property is due to the lack of metallic bonding in nonmetals, which results in a more rigid and less flexible structure. Choice B, 'lustrous,' is incorrect because nonmetals typically do not exhibit a shiny or reflective surface like metals do. Choice C, 'malleable,' is also incorrect as nonmetals lack the ability to be hammered or rolled into thin sheets like metals. Choice D, 'conductive,' is incorrect since nonmetals are generally poor conductors of electricity compared to metals.