Question 1

Which of the following is NOT one of the Earth's four major spheres?

Accepted Answer

Biosilicate

Question 2

Aluminum is commonly used in construction and packaging. Which statement best explains why aluminum is preferred over iron for certain applications, even though aluminum is more reactive than iron?

Accepted Answer

Aluminum is less dense than iron and does not rust when exposed to air.

Question 3

Which two elements are the most abundant in the Earth's crust by percentage?

Accepted Answer

Oxygen and silicon

Question 4

A factory releases nitrogen oxides into the atmosphere, which later contribute to smog formation in a nearby city. This is an example of:

Accepted Answer

Industrial pollution affecting photochemical smog

Question 5

Which layer of the atmosphere contains the majority of weather phenomena and is closest to Earth's surface?

Accepted Answer

Troposphere

Question 6

Why is atmospheric nitrogen ($\mathrm{N_2}$) not directly usable by most living organisms?

Accepted Answer

It has a strong triple bond that makes it chemically inert.

Question 7

Which of the following best describes biochemical oxygen demand (BOD) in water treatment?

Accepted Answer

The amount of oxygen required by microorganisms to decompose organic matter in water

Question 8

A city is considering using seawater for its drinking supply. Which property of water makes seawater unsuitable for direct human consumption?

Accepted Answer

High salinity

Question 9

Which process is primarily responsible for removing large solids from wastewater during primary treatment?

Accepted Answer

Physical settling and screening

Question 10

Which of the following is a greenhouse gas that is produced by burning fossil fuels?

Accepted Answer

Carbon dioxide ($\mathrm{CO_2}$)

Question 11

Which statement best describes the first law of thermodynamics?

Accepted Answer

Energy cannot be created or destroyed, only transformed from one form to another.

Question 12

A chemical reaction is carried out at a higher temperature. What effect does this generally have on the reaction rate?

Accepted Answer

It increases the reaction rate.

Question 13

Which of the following is an example of potential energy?

Accepted Answer

A stretched rubber band

Question 14

Which renewable energy source directly converts sunlight into electricity?

Accepted Answer

Solar photovoltaic cells

Question 15

Which of the following is a disadvantage of nuclear fission power plants?

Accepted Answer

Production of radioactive waste

Question 16

Which equation represents the conservation of energy according to the first law of thermodynamics?

Accepted Answer

$\Delta E = q + w$

Question 17

A reaction is exothermic. Which statement is true about the energy changes involved?

Accepted Answer

The system releases energy to the surroundings.

Question 18

Which factor does NOT generally affect the rate of a chemical reaction?

Accepted Answer

Color of the reactants

Question 19

Which of the following is a correct statement about the second law of thermodynamics?

Accepted Answer

The entropy of an isolated system always increases over time.

Question 20

Which of the following is a major source of photochemical smog in urban areas?

Accepted Answer

Automobile exhaust

Introduction to Chemistry: Key Concepts and Problems Overview

Study Guide - Practice Questions

Study Guide - Flashcards