Question 1

Which of the following best defines a solution?

Accepted Answer

A homogeneous mixture of two or more substances — A solution is a homogeneous mixture where the solute is uniformly distributed in the solvent at the molecular level, making it appear as a single phase.

Question 2

In a sugar solution, which is the solvent and which is the solute?

Accepted Answer

Water is solvent and sugar is solute — In a sugar solution, water is present in larger amount and acts as the solvent, while sugar is the solute present in smaller amount.

Question 3

Which of the following is NOT a state in which solutions can exist?

Accepted Answer

Plasma solution — Solutions can exist as solid (alloys), liquid (sugar in water), or gas (air). Plasma is not a state in which solutions are classified in this context.

Question 4

What happens at the molecular level when a solute dissolves in a solvent?

Accepted Answer

Solute particles get surrounded by solvent particles and disperse uniformly — During dissolving, solute particles separate and become surrounded by solvent molecules, leading to a uniform distribution without chemical change.

Question 5

Fill in the blank: The maximum amount of solute that can dissolve in a given amount of solvent at a particular temperature to form a saturated solution is called _____.

Accepted Answer

solubility — Solubility is defined as the maximum quantity of solute that can dissolve in a solvent at a specific temperature to form a saturated solution.

Question 6

Which statement correctly describes the effect of temperature on the solubility of solids and gases?

Accepted Answer

Solubility of solids increases and solubility of gases decreases with temperature — For most solids, solubility increases with temperature as particles gain energy, while for gases, increased temperature causes gas molecules to escape, reducing solubility.

Question 7

What is a saturated solution?

Accepted Answer

A saturated solution is one that contains the maximum amount of solute that can dissolve in a given amount of solvent at a particular temperature. For example, when no more sugar can dissolve in water at room temperature, the solution is saturated. — A saturated solution has reached its solubility limit at a given temperature, meaning any additional solute will not dissolve and may settle or crystallize.

Question 8

Explain the difference between unsaturated and supersaturated solutions with examples.

Accepted Answer

An unsaturated solution can dissolve more solute at a given temperature; for example, sugar dissolved in a small amount in water. A supersaturated solution contains more solute than the saturation point and is unstable; for example, sugar dissolved in hot water and cooled carefully can form a supersaturated solution which crystallizes upon disturbance. — Unsaturated solutions have the capacity to dissolve more solute, whereas supersaturated solutions hold excess solute beyond saturation and are prone to crystallization.

Question 9

Why does sugar dissolve faster in hot water compared to cold water?

Accepted Answer

Sugar dissolves faster in hot water because higher temperature increases the kinetic energy of water molecules, allowing them to interact more effectively with sugar particles and dissolve them quicker. For example, sugar cubes dissolve faster in boiling water than in cold water. — Increased temperature causes solvent molecules to move faster, enhancing the rate at which solute particles separate and disperse, speeding up dissolving.

Question 10

Which of the following correctly describes Henry's Law related to gas solubility?

Accepted Answer

Solubility of a gas in a liquid is directly proportional to the pressure of the gas above the liquid — Henry's Law states that increasing the pressure of a gas above a liquid increases the amount of gas dissolved in the liquid, as seen in carbonated drinks.

Question 11

What causes the fizzing when a soda bottle is opened?

Accepted Answer

Fizzing occurs because when the soda bottle is opened, the pressure above the liquid decreases suddenly. This reduces the solubility of carbon dioxide gas in the liquid, causing the gas to escape as bubbles, producing fizz. — The decrease in pressure causes dissolved gas to come out of solution, forming visible bubbles and sound.

Question 12

Match the following types of solutions with their examples:

Accepted Answer

— Solid solutions are alloys like brass, liquid solutions include sugar dissolved in water, and gaseous solutions include air.

Question 13

Explain why dissolving is considered a physical change and not a chemical change.

Accepted Answer

Dissolving is a physical change because the solute particles separate and disperse in the solvent without forming new substances. The process is reversible by evaporating the solvent to recover the solute, unlike chemical changes which produce new substances. — Since no new chemical bonds are formed or broken and the solute can be recovered, dissolving is physical.

Question 14

Why do polar solvents dissolve polar solutes but not non-polar solutes?

Accepted Answer

Polar solvents dissolve polar solutes because both have similar intermolecular forces, allowing solvent molecules to surround and separate solute particles effectively. Non-polar solutes do not dissolve well in polar solvents due to lack of similar forces, leading to poor interaction. — Like dissolves like; similar polarity leads to better solubility due to compatible intermolecular attractions.

Question 15

Describe the process of hydration in the context of dissolving salt in water.

Accepted Answer

Hydration is the process where water molecules surround the separated salt ions when salt dissolves. The polar water molecules attract and stabilize the positive and negative ions, preventing them from recombining and keeping them dispersed in the solution. — Hydration involves solvent molecules forming a shell around solute particles, aiding dissolution and stability.

The Amazing World of Solutes, Solvents, and Solutions

The Amazing World of Solutes, Solvents, and Solutions — Study Notes

Introduction

Solubility and Factors Affecting Solubility

How Does Dissolving Happen?

Practice Questions — The Amazing World of Solutes, Solvents, and Solutions

All 13 Chapters in Curiosity