Use Dalton's theory to explain why potassium nitrate from India or Italy has the same mass percents of \(\mathrm{K}, \mathrm{N},\) and \(\mathrm{O}\).

Dalton's Atomic Theory is a fundamental concept in chemistry that explains the nature of matter. According to this theory, everything is made up of tiny particles called atoms. These atoms are indivisible and cannot be created or destroyed in chemical reactions. One key point of Dalton’s Atomic Theory is that atoms of the same element are identical. This means all potassium atoms, for example, have exactly the same mass and properties, no matter where they are found. Dalton also introduced the idea that chemical compounds form when atoms of different elements combine in definite, fixed ratios. This understanding helps explain why potassium nitrate from India and Italy would have the same composition and properties.

A chemical compound is a substance formed when two or more different kinds of atoms bond together. Potassium nitrate (KNO₃) is an example of a chemical compound. It consists of potassium (K), nitrogen (N), and oxygen (O) atoms. The molecular formula KNO₃ tells us that in each molecule of potassium nitrate, there is 1 atom of potassium, 1 atom of nitrogen, and 3 atoms of oxygen. Chemical compounds have fixed compositions. This means no matter where the compound is from, its composition remains the same. In our example, every molecule of potassium nitrate will always be made up of exactly 1 potassium atom, 1 nitrogen atom, and 3 oxygen atoms, whether the potassium nitrate is sourced from India or Italy.

Mass percentage is a way of expressing the concentration of an element in a compound. It is calculated by dividing the mass of the element by the total mass of the compound and then multiplying the result by 100%. Let's look at potassium nitrate (KNO₃) as an example. The molar mass of KNO₃ is calculated by adding the atomic masses of potassium (39.1 g/mol), nitrogen (14.0 g/mol), and oxygen (3 * 16.0 g/mol), which equals 101.1 g/mol. To find the mass percent of potassium, you divide 39.1 by 101.1 and multiply by 100%, giving approximately 38.7%. Similarly, the mass percentage of nitrogen is calculated as (14.0 / 101.1) * 100% ≈ 13.8%, and for oxygen, it is (3 * 16.0 / 101.1) * 100% ≈ 47.5%. These percentages will be the same for any sample of potassium nitrate, no matter where it originates, because the molecular formula KNO₃ is consistent.