pH Determination Lab
Comparing Electrolytic Strength
Principle: $pH = -\log_{10}[H_3O^+]$
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Experimental Theory & Guide
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📖
Experimental Theory & Guide
Aim
"To determine and compare the pH of solutions of strong and weak acids (HCl vs. CH₃COOH) and strong and weak bases (NaOH vs. NH₄OH)."
The Four Reagents
All four are at the same 0.1 M concentration. Two are acids and two are bases — one of each is strong and one weak. Predict each one's nature and pH before you test it.
$HCl$
🔒
predict & test
$CH_3COOH$
🔒
predict & test
$NaOH$
🔒
predict & test
$NH_4OH$
🔒
predict & test
Procedure
- 1 Select a reagent bottle from the bench.
- 2 Click on a pH Paper strip to test the drop on a glazed tile.
- 3 Click on a Test Tube to add the universal indicator solution.
🔬 The Reagent Bench
$HCl$
0.1M
$CH_3COOH$
0.1M
$NaOH$
0.1M
$NH_4OH$
0.1M
Click a bottle to select a solution
Method 1: Glazed Tile Test
Method 2: Indicator Test
🔮 Predict First
Select a reagent bottle to begin.
✓ Prediction locked — test
this reagent with the paper or indicator.
pH Reference Chart
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Experiment Log
Sample
1
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Sample
2
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Sample
3
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Sample
4
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Reasoning Journal
Observations and interpretations will appear here…
⚠️ Safety
- HCl and NaOH are corrosive — even dilute solutions harm skin and eyes; wear goggles.
- Ammonia (NH₄OH) gives pungent, irritating vapour — waft gently to smell, work in good ventilation.
- Use a dropper, never a mouth pipette; never taste any solution.
- Touch pH paper only with clean forceps; dispose of acids/bases in the labelled waste, not the sink.