pH Testing Results
Reported Values — Sorted by Average Meter Reading
To put these data in perspective, remember that pH is a
logarithmic number. Thus a group of student tests with a standard deviation
of ±1.00 pH unit would vary by a 10× difference in [H+].
Also, the actual list of substances that have been tested is a very
long list! However, many of those substances have only been tested one or
two times. Thus, to shorten the list shown here, only the substances that
have been tested at least 30 times are included.
| Substance | No. of Tests |
Avg. Paper Reading |
Avg. Meter Reading |
Std. Dev. |
|---|---|---|---|---|
| Juice‚ Lemon | 154 | 2.50 | 3.10 | ±1.26 |
| Vinegar‚ white distilled | 189 | 2.59 | 3.11 | ±1.06 |
| Beverage‚ Cola‚ Coke‚ regular | 66 | 3.10 | 3.16 | ±0.82 |
| Beverage‚ Gatorade | 40 | 2.80 | 3.22 | ±1.01 |
| Beverage‚ Cola‚ Pepsi‚ regular | 50 | 2.84 | 3.28 | ±1.11 |
| Vinegar‚ diluted | 51 | 2.97 | 3.77 | ±1.34 |
| Juice‚ Orange | 49 | 4.02 | 3.96 | ±0.94 |
| Beverage‚ Cola‚ Pepsi‚ Diet | 30 | 3.82 | 4.00 | ±1.35 |
| Beverage‚ Mt. Dew | 100 | 3.80 | 4.02 | ±1.17 |
| Beverage‚ Sprite | 52 | 3.91 | 4.08 | ±1.51 |
| Beverage‚ Tea‚ Iced‚ Lipton | 34 | 4.16 | 4.82 | ±1.78 |
| Beverage‚ Cola‚ Coke‚ Diet | 39 | 4.14 | 5.07 | ±1.31 |
| Beverage‚ Coffee‚ black | 36 | 4.92 | 5.17 | ±1.38 |
| Drug‚ Hydrogen Peroxide | 30 | 4.75 | 5.37 | ±0.95 |
| Detergent‚ Rinse‚ Jet Dry | 37 | 6.27 | 6.16 | ±2.02 |
| Water‚ bottled | 35 | 6.40 | 6.24 | ±1.72 |
| Food‚ Salt‚ Table with water | 35 | 5.46 | 6.46 | ±1.25 |
| Disinfectant‚ Gel‚ Hand or Bath | 32 | 5.75 | 6.68 | ±1.80 |
| Shampoo | 38 | 5.28 | 6.77 | ±1.16 |
| Water‚ tap‚ city | 37 | 6.31 | 6.82 | ±1.26 |
| Beverage‚ Milk‚ whole | 39 | 6.46 | 6.85 | ±1.51 |
| Drug‚ Antacid‚ Tums | 51 | 6.82 | 7.28 | ±1.61 |
| Detergent‚ dishwashing liquid | 38 | 6.41 | 7.28 | ±1.88 |
| Food‚ Baking Soda with water | 42 | 7.67 | 8.02 | ±0.67 |
| Detergent‚ dishwashing liquid‚ Ivory | 51 | 6.91 | 8.08 | ±1.96 |
| Drug‚ Antacid‚ Rolaids | 42 | 7.24 | 8.31 | ±1.77 |
| Laundry‚ Starch‚ liquid | 47 | 8.74 | 8.49 | ±0.69 |
| Cleaner‚ Glass‚ Windex | 181 | 9.48 | 9.42 | ±1.83 |
| Disinfectant‚ Lysol | 44 | 8.69 | 9.57 | ±2.26 |
| Cleaner‚ Glass | 78 | 9.05 | 9.79 | ±1.20 |
| Cleaner‚ Bathroom | 43 | 9.41 | 10.05 | ±2.48 |
| Cleaner‚ Ammonia‚ diluted | 41 | 9.73 | 10.28 | ±2.36 |
| Cleaner‚ Ammonia‚ full strength | 112 | 10.44 | 10.46 | ±1.10 |