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What is a Solute (dissolved substance)?
Grade Level:
Class 7
Space Technology, EVs, Climate Change, Biotechnology, HealthTech, Robotics, Chemistry, Physics
Definition
What is it?
A solute is the substance that gets dissolved in another substance to form a solution. Think of it as the 'smaller part' that disappears into the 'bigger part'. For example, when you make nimbu pani, the sugar and salt are solutes.
Simple Example
Quick Example
Imagine you are making a glass of Rooh Afza. You take a spoonful of the red Rooh Afza syrup and add it to water. The Rooh Afza syrup is the solute here because it dissolves in the water to give that sweet, colourful drink.
Worked Example
Step-by-Step
Let's say you want to make a cup of chai. You have water, milk, sugar, and tea leaves.
Step 1: You boil water (this is your solvent for the tea leaves).
---Step 2: You add tea leaves to the boiling water. The tea leaves are a solute, as some of their colour and flavour dissolve in the water.
---Step 3: You add milk. The milk mixes but doesn't dissolve in the same way.
---Step 4: You add sugar. The sugar completely disappears into the hot chai.
---Step 5: The sugar is a solute because it dissolves in the hot chai to make it sweet.
---Answer: In this example, the tea leaves (partially) and the sugar (completely) are the solutes.
Why It Matters
Understanding solutes is key in fields like Biotechnology for creating medicines, in Chemistry for experiments, and even in Climate Change studies to understand how pollutants dissolve in water. Scientists, pharmacists, and environmental engineers all work with solutes daily.
Common Mistakes
MISTAKE: Thinking the solute is always the liquid part. | CORRECTION: The solute can be a solid (like sugar), a liquid (like Rooh Afza syrup), or even a gas (like carbon dioxide in soda). It's about what dissolves.
MISTAKE: Believing the solute is always the larger quantity. | CORRECTION: The solute is usually the substance present in a smaller amount compared to the solvent. For example, a pinch of salt in a glass of water.
MISTAKE: Confusing a mixture with a solution. | CORRECTION: A solute dissolves completely to form a uniform solution (like sugar in water). If something just mixes but doesn't dissolve (like sand in water), it's a mixture, not a solution, and sand is not a solute.
Practice Questions
Try It Yourself
QUESTION: When you mix Bournvita powder with milk, which substance is the solute? | ANSWER: The Bournvita powder is the solute.
QUESTION: You add a drop of food colouring to a glass of water. Is the food colouring the solute or the solvent? Explain. | ANSWER: The food colouring is the solute because it dissolves and spreads throughout the water.
QUESTION: Your mother makes rasam. She adds tamarind pulp to water, then adds salt, and finally some spices. Identify all the solutes in this process that dissolve to form the rasam. | ANSWER: The tamarind pulp, salt, and soluble parts of the spices are the solutes.
MCQ
Quick Quiz
Which of these is a solute?
Water in nimbu pani
Sugar in nimbu pani
The glass holding the nimbu pani
Ice cubes in nimbu pani
The Correct Answer Is:
B
Sugar is the solute because it dissolves in the water to make nimbu pani. Water is the solvent, the glass is the container, and ice cubes melt but don't dissolve in the same way sugar does.
Real World Connection
In the Real World
When you buy bottled mineral water, it contains various dissolved minerals like calcium and magnesium. These minerals are solutes that have dissolved in the water, making it 'mineral water'. In health tech, doctors might prescribe ORS (Oral Rehydration Solution) where salts and sugar are solutes dissolved in water to help rehydrate patients, especially children during illness.
Key Vocabulary
Key Terms
SOLUTION: A uniform mixture formed when a solute dissolves in a solvent. | SOLVENT: The substance that dissolves the solute, usually present in a larger amount. | DISSOLVE: To mix completely with a liquid to form a solution. | UNIFORM MIXTURE: A mixture where all parts look the same, like sugar water.
What's Next
What to Learn Next
Now that you understand what a solute is, you should learn about the 'Solvent'. The solvent is the other crucial part of a solution, and understanding both will help you fully grasp how solutions are formed and how they work.
