Back to Class 12 Chemistry, Part 1 (NCERT)BackChapter

Solutions

How to express concentration, how gases and liquids dissolve, and the colligative properties that let you find molar masses.

4 micro-lessons7 concepts

Preview · progress not saved — Chapter 1 is free

The Scuba Diver's Dilemma

Why divers get the bends, and why antifreeze works: this chapter explains both.

By the end of this chapter, you'll be able to solve problems like this: If a scuba diver breathes air at high pressure underwater, exactly how much extra nitrogen dissolves in their blood? And why do they get a dangerous condition called "the bends" if they surface too quickly?

1 / 3

Pressure and Gas Solubility in Diving

How Henry’s Law applies when a scuba diver goes deeper underwater.

A scuba diver exploring a coral reef underwater, with visible air bubbles rising to the surface, illustrating gas solubility under pressure. photorealistic educational scene, shot on 35mm lens, natural lighting with soft bokeh, warm inviting color grading, golden hour or soft diffused daylight, professional documentary photography quality, culturally respectful

Click to zoom

As a scuba diver descends deeper into the sea, the surrounding pressure increases. According to Henry’s Law, higher pressure makes more nitrogen dissolve in the blood.

This is why divers must come up slowly, so the dissolved nitrogen can safely leave the body without forming bubbles.

What You Already Know

Tick the mole and molar-mass skills you already have.

0 / 4 done0%

Before You Start — Check What You Know

Quick Questions Before You Start

A few questions on moles and molar mass. Getting them wrong is fine.

1 / 5

If you dissolve $5.0 \text{ g}$ of sodium hydroxide ( $\text{NaOH}$ ) in water, how many moles of $\text{NaOH}$ are you using? (Molar mass of $\text{NaOH} = 40 \text{ g/mol}$ )

Hint

Concept: prerequisite-math

concepts · 7

← backClass 12 Chemistry, Part 1 (NCERT)next →Expressing Concentration

Quick Questions Before You Start

A few questions on moles and molar mass. Getting them wrong is fine.

1 / 5

If you dissolve $5.0 \text{ g}$ of sodium hydroxide ( $\text{NaOH}$ ) in water, how many moles of $\text{NaOH}$ are you using? (Molar mass of $\text{NaOH} = 40 \text{ g/mol}$ )

Hint

Concept: prerequisite-math

Solutions

The Scuba Diver's Dilemma

Pressure and Gas Solubility in Diving

What You Already Know

Quick Questions Before You Start

Expressing Concentration

Solubility And Henry's Law

Vapour Pressure And Raoult's Law

Colligative Properties: Vapour Pressure And Boiling Point

Colligative Properties: Freezing Point And Osmosis

Abnormal Molar Masses

Chapter Review: Solutions

The Scuba Diver's Dilemma

Pressure and Gas Solubility in Diving

What You Already Know

Quick Questions Before You Start