Examples of how Dalton's atomic theory explained chemical laws.

📚 Quick Study Guide

⚛️ Dalton's Atomic Theory (1803) proposed that all matter is composed of indivisible and indestructible atoms.

⚖️ Law of Conservation of Mass: * 🍎 Atoms are neither created nor destroyed in chemical reactions. * ⚗️ The total mass of reactants equals the total mass of products.

🎯 Law of Definite Proportions: * 🧪 A given chemical compound always contains the same elements in the same proportion by mass. * 📊 Example: Water ($H_2O$) always has a 2:1 ratio of hydrogen to oxygen atoms.

🧮 Law of Multiple Proportions: * 🧪 When two elements form more than one compound, the ratios of the masses of one element that combine with a fixed mass of the other element are in the ratio of small whole numbers. * 📊 Example: Carbon and Oxygen form CO and $CO_2$. For a fixed mass of carbon, the masses of oxygen are in a 1:2 ratio.

🧪 Practice Quiz

1. Which of Dalton's postulates best explains the Law of Conservation of Mass?
   1. Atoms of a given element are identical.
   2. Atoms are indivisible and indestructible.
   3. Atoms combine in simple whole-number ratios.
   4. Chemical reactions involve the rearrangement of atoms.
2. The Law of Definite Proportions states that:
   1. The mass of reactants must equal the mass of products.
   2. Elements combine in a fixed ratio in a compound.
   3. Atoms cannot be created or destroyed.
   4. The volume of gases are proportional to their amount.
3. Which law does the following scenario illustrate: Two compounds of copper and oxygen are analyzed. One contains 88.8 g of copper and 11.2 g of oxygen, and the other contains 79.9 g of copper and 20.1 g of oxygen. For a fixed amount of copper, the oxygen masses are in a simple whole number ratio.
   1. Law of Conservation of Mass
   2. Law of Definite Proportions
   3. Law of Multiple Proportions
   4. Avogadro's Law
4. Which statement is NOT a part of Dalton's Atomic Theory?
   1. All matter is composed of extremely small particles called atoms.
   2. Atoms of a given element are identical in size, mass, and other properties.
   3. Atoms can be subdivided into protons, neutrons, and electrons.
   4. Atoms are neither created nor destroyed in chemical reactions.
5. Water ($H_2O$) always contains two hydrogen atoms for every one oxygen atom. This demonstrates which law?
   1. Law of Conservation of Mass
   2. Law of Definite Proportions
   3. Law of Multiple Proportions
   4. Ideal Gas Law
6. Carbon and oxygen can form CO and $CO_2$. If you have 12g of carbon in each compound, the mass of oxygen in $CO_2$ is twice that in CO. This illustrates:
   1. Law of Conservation of Mass
   2. Law of Definite Proportions
   3. Law of Multiple Proportions
   4. Law of Combining Volumes
7. According to Dalton, what happens to atoms during a chemical reaction?
   1. They are created.
   2. They are destroyed.
   3. They are rearranged.
   4. Their mass changes.