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What is an Aqueous Solution (chemistry)?
Grade Level:
Class 7
Space Technology, EVs, Climate Change, Biotechnology, HealthTech, Robotics, Chemistry, Physics
Definition
What is it?
An aqueous solution is a special type of solution where water acts as the solvent. This means a substance (solute) is dissolved in water to form a uniform mixture. Water is often called the 'universal solvent' because it can dissolve many things.
Simple Example
Quick Example
Imagine you're making nimbu paani (lemonade) at home. You take a glass of water and add some sugar and a squeeze of lemon. The sugar and lemon juice dissolve completely in the water. This nimbu paani you just made is an aqueous solution because water is the main liquid dissolving everything.
Worked Example
Step-by-Step
Let's say you want to make a simple salt solution for an experiment.
1. Take 100 ml of clean drinking water in a glass.
2. Measure out 5 grams of common table salt (sodium chloride).
3. Add the 5 grams of salt to the 100 ml of water.
4. Stir the mixture well with a spoon until all the salt particles disappear and the water looks clear again.
5. You have now successfully prepared an aqueous solution of salt in water. The water is the solvent, and the salt is the solute.
Why It Matters
Aqueous solutions are vital in almost every field! From making medicines in HealthTech to understanding chemical reactions in Biotechnology, they are everywhere. Scientists in fields like Climate Change research and even Space Technology use their knowledge of aqueous solutions to develop new materials and understand planetary environments.
Common Mistakes
MISTAKE: Thinking all solutions are aqueous solutions. | CORRECTION: Only solutions where water is the solvent are aqueous. If oil dissolves in petrol, it's a solution, but not an aqueous one.
MISTAKE: Confusing a suspension with an aqueous solution. | CORRECTION: In an aqueous solution, the solute completely dissolves and doesn't settle down. In a suspension (like muddy water), particles settle over time.
MISTAKE: Believing that 'aqueous' means 'acidic' or 'basic'. | CORRECTION: 'Aqueous' simply refers to water being the solvent. An aqueous solution can be neutral, acidic, or basic depending on what is dissolved in it.
Practice Questions
Try It Yourself
QUESTION: Is a mixture of sand and water an aqueous solution? Why or why not? | ANSWER: No, it is not. Sand does not dissolve in water; it just settles at the bottom, so it's a suspension, not a solution.
QUESTION: You mix some turmeric powder in water to make a paste for a ritual. Is this an aqueous solution? Explain. | ANSWER: Not really. While turmeric mixes with water, it doesn't fully dissolve to form a clear solution. It forms a suspension or a colloidal mixture, where particles remain dispersed but visible.
QUESTION: Your mother dissolves a spoonful of glucose powder in a glass of water for energy. Is the glucose water an aqueous solution? What are the solute and solvent here? | ANSWER: Yes, the glucose water is an aqueous solution. The solute is glucose powder, and the solvent is water.
MCQ
Quick Quiz
Which of the following is an example of an aqueous solution?
Oil mixed with petrol
Sugar dissolved in milk
Salt dissolved in water
Sand mixed with water
The Correct Answer Is:
C
An aqueous solution requires water as the solvent. Salt dissolved in water forms a clear, uniform mixture where water is the solvent. Oil and petrol, sugar and milk, and sand and water do not fit this definition.
Real World Connection
In the Real World
Many everyday things around us in India are aqueous solutions. The ORS (Oral Rehydration Solution) given to someone feeling unwell is an aqueous solution of salts and sugar in water. Even the water purification plants in our cities use processes that often involve chemical reactions happening in aqueous solutions to make water safe for drinking.
Key Vocabulary
Key Terms
SOLUTION: A uniform mixture formed when one substance dissolves in another. | SOLVENT: The substance that dissolves another substance. | SOLUTE: The substance that gets dissolved. | AQUEOUS: Related to water; containing water.
What's Next
What to Learn Next
Great job learning about aqueous solutions! Next, you can explore 'Solubility' to understand why some things dissolve more easily in water than others. This will help you understand how much sugar you can dissolve in your chai!
