The potential of Hydrogen, or pH, scale was invented by the Danish biochemist Soren Peter Lauritz Sorensen. He introduced this scale in 1909 to measure the acidity and basicity of substances. More »

Sulfuric acid has a pH of 0.3 at a normality of 1 N, a pH of 1.2 at 0.1 N and a pH of 2.1 at 0.01 N. When using molar concentration, sulfuric acid has a pH of 2.75 at 1 millimole per liter, a pH of 1.87 at 10 millimoles ... More »

Although shampoos vary in acidity and alkalinity, most shampoos range from 5 to 7 on the pH scale. The best shampoos are those that are slightly acidic to neutral. The higher the pH number, the harsher the shampoo on a p... More »

The pH range for Sorensen’s sodium phosphate buffer is 5.8 to 8. The pH range for 0.2M sodium dihydrogen phosphate and disodium hydrogen phosphate stock solutions were determined by Sorensen. Hence, the buffer solution i... More »

Giuseppe Mercalli invented the Mercalli intensity scale in 1902 as a way to measure the effects of an earthquake. The scale is based off of the observations of the people who experienced the earthquake. More »

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The hardness scale, or the Mohs Hardness Scale, was developed by Friedrich Mohs, a German geologist and mineralogist, in 1812. This qualitative test was the first widely used field test among geologists. More »

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The pH scale is a measure of how acidic or basic a liquid substance is. The pH is calculated as a negative logarithmic function of the concentration of hydrogen ions, which are acidic by nature. A high concentration of h... More »