Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Matter is everything around us that has mass and takes up space, and it is made of tiny particles called atoms and molecules like .
A Mixture is a physical combination of two or more substances where each substance retains its own chemical properties.
A Solution is a type of homogeneous mixture where one substance (the solute) dissolves completely into another (the solvent). A common example is salt () dissolved in water ().
The Solute is the substance that is being dissolved (e.g., sugar), while the Solvent is the substance that does the dissolving (e.g., water).
A Suspension is a heterogeneous mixture containing large particles that do not dissolve and will eventually settle at the bottom over time, such as sand in .
Solubility refers to the maximum amount of solute that can dissolve in a specific amount of solvent at a given temperature.
Concentration describes the ratio of solute to solvent. A 'dilute' solution has very little solute, while a 'concentrated' solution has a large amount of solute.
The Law of Conservation of Mass states that the total mass of a mixture is equal to the sum of the masses of the individual components: .
📐Formulae
(For most solid solutes in liquid solvents)
💡Examples
Problem 1:
If a student mixes of sugar into of water (), what is the total mass of the resulting sugar solution?
Solution:
Explanation:
According to the Law of Conservation of Mass, the mass of the solution is the sum of the solute and the solvent: .
Problem 2:
You have two beakers of water. Beaker A has teaspoon of salt () and Beaker B has teaspoons of salt. Which solution is more concentrated?
Solution:
Beaker B
Explanation:
Concentration is defined as the amount of solute per volume of solvent. Since Beaker B has more solute () in the same amount of water, it is more concentrated.
Problem 3:
Identify whether a mixture of muddy water is a solution or a suspension, and explain why.
Solution:
Suspension
Explanation:
Muddy water is a suspension because the soil particles are large and do not dissolve. If left undisturbed, the particles will settle at the bottom due to gravity.