FOUNDATIONS OF CHEMISTRY FOR YOUNG STARS - Lesson 16: Concentration of Solutions and Molarity – Measuring Strength Like Palm Wine and Salt Water

 

🧂 Light for the Living – Chemistry in Everyday Life

Lesson 16: Concentration of Solutions and Molarity – Measuring Strength Like Palm Wine and Salt Water

📍 Scene: Odi Creek Village, Bayelsa State
👨🏾‍🏫 Main Character: Teacher Tamuno, the Riverbank Scientist

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🌊 Scene 1 – “The Taste of Strength”

The morning mist rolled gently over Odi Creek in Bayelsa State. Canoes rocked on the water as fishermen returned from night fishing. From nearby kitchens came the rich aroma of smoked fish and bubbling palm oil.

Under a mangrove tree, near the water’s edge, Teacher Tamuno was setting up his little open-air classroom. On his wooden table sat bottles of palm wine, bowls of salt, a calabash of creek water, and a smiling group of curious children.

He clapped his hands.

“Today, my children, we shall talk about strength! Not the kind your father boasts about after eating pounded yam — but the kind chemists use when talking about mixtures.”

The children laughed.

Little Ebiye raised her hand.

“Teacher, when my papa drinks palm wine, he says some are ‘strong’ and some are ‘sweet’. Is that the same strength you mean?”

“Exactly!” Teacher Tamuno chuckled. “Chemistry also talks about strength — only we call it concentration.”

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🍶 1. What Is a Solution?

Teacher Tamuno lifted a bottle of creek water mixed with salt.

“When we dissolve something — like salt, sugar, or palm wine spirit — in water, we get what we call a solution.”

He wrote in the sand with a stick:

• Solute → the substance that dissolves (e.g., salt).

• Solvent → the liquid that does the dissolving (e.g., water).

• Solution → the uniform mixture that results.

He added a spoon of salt into a cup of water and stirred.

“This one is dilute — weak in taste.”

Then he added five spoons to another cup.

“This one is concentrated — strong and salty!”

The children leaned in. Tari pretended to taste.

“Yeeh! This one go cut tongue!”

The class roared with laughter.

“You’ve just tasted concentration — the amount of solute present in a given amount of solvent,” said Teacher Tamuno.

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⚖️ 2. Ways to Express Concentration

Teacher Tamuno drew two jars in the sand — one with a little salt, one with plenty.

“We can express concentration in two main ways,” he said:

1️⃣ Mass Concentration (g/dm³) – how many grams of solute are in one cubic decimetre (litre) of solution.
2️⃣ Molar Concentration (mol/dm³) or Molarity (M) – how many moles of solute are in one cubic decimetre of solution.

He wrote the key formula on his slate:

$$\mathrm{<b>M</b> }= \frac{\text{Number of moles of solute ÷ }}{\text{Volume of solution in dm³}}$$

Then he looked up and smiled.

“It’s just like asking: How many cups of sugar did Mama Ebi use to prepare this whole pot of zobo?”

The class nodded eagerly.

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🪣 3. Local Analogy – Mixing Palm Wine

He brought out two calabashes of palm wine — one clear and light, the other thick and frothy.

“If I pour one cup of spirit into five cups of water,” he said, “the wine will be strong.
If I pour one cup of spirit into ten cups of water, it will be weak.”

He grinned.

“So, the more spirit per cup of water, the higher the concentration. That’s why traders who dilute palm wine make it less concentrated — to sell more. But at festivals, the elders prefer the ‘original’ — hot, strong, and pure!”

The children giggled knowingly.

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🧮 4. Calculating Concentration (Molarity)

Example 1:

If 5 g of sodium chloride (NaCl) is dissolved in 250 cm³ of water, find its concentration in mol/dm³.
(Na = 23, Cl = 35.5)

Step 1: Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Step 2: Moles = 5 ÷ 58.5 = 0.0855 mol
Step 3: Volume = 250 cm³ ÷ 1000 = 0.25 dm³
Step 4:

$$\mathrm{M }=\frac{\mathrm{0.0855 }}{}$$÷ 0.25 = 0.342 mol/dm³ 

“So the salt water’s strength is about 0.34 molar,” said Teacher Tamuno.
“Add more salt or reduce the water — the concentration rises, just like stronger palm wine!”

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Example 2:

Find the molarity of 36 g of water (H₂O) if molar mass = 18 g/mol and volume = 1 dm³.

$$\text{Moles }= \frac{\mathrm{36g }}{}$$÷ 18g/mol = 2 mol 

$$\mathrm{M }= \frac{2}{}$$mol $$\frac{\mathrm{ }}{}$$÷ 1dm³ = 2 mol/dm³

“That means there are 2 moles of water molecules per litre — a very tight, ‘two-shots-only’ concentration!”

The class laughed until tears rolled.

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🌴 5. Chemistry by the River – Everyday Applications

Teacher Tamuno pointed toward the water.

“Even our creek obeys chemistry.”

He listed examples:

🌊 Saltiness of Creek Water:
During the dry season, evaporation removes water, leaving more salt — increasing concentration.

🍶 Palm Wine Brewing:
As sugar ferments into alcohol, concentration of ethanol increases — that’s why old wine hits harder!

🧼 Soap Making:
Local women use sodium hydroxide and oil. The right concentration makes the soap firm and clean — but too much concentration, and it burns the skin; too little, and it won’t lather (foam).

“So you see,” said Teacher Tamuno proudly, “chemistry lives right here with us — in our pots, rivers, and bottles.”

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🧂 6. Dilution – Making a Solution Weaker

He held up a bottle half-full of salty water.

“If I add more water, what happens?”

“E go less salty!” the children shouted.

“Correct! That’s dilution — reducing concentration by adding more solvent.”

He wrote in the sand:

$$C_{\mathrm{<span\; style="font-size:\; xx-small;">1</span>}}{V}_{\mathrm{<span\; style="font-size:\; xx-small;">1</span>}}=C_{\mathrm{<span\; style="font-size:\; xx-small;">2</span>}}{V}_{\mathrm{<span\; style="font-size:\; xx-small;">2</span>}}$$

Where:

• $C_{\mathrm{<span\; style="font-size:\; xx-small;">1</span>\; =\; initial\; concentration}}$

• $V_{\mathrm{<span\; style="font-size:\; xx-small;">1</span>}}$ = initial volume

• $C_{\mathrm{<span\; style="font-size:\; xx-small;">2</span>}}$ = final concentration

• $V_{\mathrm{<span\; style="font-size:\; xx-small;">2</span>}}$ = final volume

“This is how chemists, and even traders, mix accurately — whether it’s palm wine or medicine.”

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📘 7. Practice Time

A. Fill in the Blanks
1️⃣ The amount of solute dissolved in a given volume of solvent is called __________.
2️⃣ The unit of molarity is __________.
3️⃣ Molarity = number of __________ ÷ volume in __________.
4️⃣ Adding more water to a solution __________ its concentration.

B. Solve These
1️⃣ Find the molarity of 10 g NaOH dissolved in 500 cm³ of water. (Na = 23, O = 16, H = 1)
2️⃣ 0.1 mol of sugar is dissolved to make 0.5 dm³ of solution. What is its molarity?
3️⃣ A 2 M solution of HCl is diluted from 100 cm³ to 200 cm³. Find the new concentration.
4️⃣ Explain how soap makers use concentration to get the right texture of soap.

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⚗️ 8. Summary Table

Term	Meaning	Unit	Example
Solute	Substance dissolved	–	Salt in water
Solvent	Liquid (or gas) doing the dissolving	–	Water
Concentration	Amount of solute in a given solvent	g/dm³ or mol/dm³	Saltiness of creek water
Molarity (M)	Moles of solute per dm³ of solution	mol/dm³	0.5 M NaCl
Dilution	Decreasing concentration by adding solvent	–	Adding water to palm wine

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💬 9. Moral Reflection

As the tide rose and the waves kissed the shore, Teacher Tamuno closed his book and said softly:

“My children, concentration teaches us balance. Too much or too little of anything can spoil the mixture — in food, in study, or in life. The right measure brings harmony, just as the best palm wine is neither too strong nor too weak.”

From her kitchen, Mama Ebi called out, laughing,

“Next time, teach them how to make soap that shines like my forehead!”

The children burst out laughing. Even the fishermen nearby joined in.

For that day, chemistry had danced joyfully with real life.

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🧠 Lesson Summary

• Concentration tells how much solute is present in a solution.

• Molarity (M) = moles of solute ÷ volume in dm³.

• Dilution lowers concentration by adding more solvent.

• Chemistry explains real-life things — saltiness of water, strength of palm wine, and quality of soap.

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✏️ Practice Quiz

1️⃣ Define molarity and state its formula.
2️⃣ A 0.5 mol of NaCl is dissolved in 2 dm³ of solution. What is its molarity?
3️⃣ Explain how adding water changes the concentration of palm wine.
4️⃣ Why is knowing concentration important in soap or medicine making?
5️⃣ Describe one example of dilution in your community.

🌿 #LightForTheLiving #ScienceByTheCreek #ChemistryForLife #BayelsaVillageLessons #PalmWineAndSaltWater #MolarityMadeSimple