Abnormal Molar Mass
Chapter Name : Solutions |
Sub Topic Code : 102_12_02_07_01 |
Topic Name : Abnormal Molar Mass |
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Sub Topic Name : Abnormal Molar Mass |
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Introduction
• Molar mass that is either lower or higher than the expected or normal value is called as abnormal molar mass. • Abnormal molar mass is the experimentally determined molar mass and calculated colligative properties are obtained by assuming that the non-volatile solute is neither associated nor dissociated. • Van’t Hoff introduced a factor i, known as the Van’t Hoff factor, to account for the extent of dissociation or association.
Pre-Requisites:
Molar mass, ionic compound,
Activity:
The weight or mass of any substance is never exact as calculated. Use a weighing balance to prove this with different substances.
Real Life Question:
The weight of a pack of e.g. Sugar salt, flour is always different, (usually) more than the actual weight of the substance in the pack.
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Abnormal molar mass | Molar mass that is either lower or higher than the expected or normal value is called as abnormal molar mass. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Bar of chocolate | Take the chocolate and break it into two, you would observe that the total weight of the bar is different from the two pieces obtained after breaking the bar. |
Places to visit :
Kitchen, department store
Practical examples around us
| Examples | Explainations |
|---|---|
| Weight of food items | The total weight of a group of items would always be less as when compared to the weighing each item separately and then adding it up. |
What you learn in Theory:
Molar mass that is either lower or higher than the expected or normal value is called as abnormal molar mass.
What you learn in Practice:
The measured and the calculated molar mass are always different.