Chemistry5 min read
Parts Per Million (ppm) in Water: mg/L Made Simple
25 mg of solute dissolved in 5 litres of water is 5 mg/L, which is about 5 ppm. Learn when mg/L equals ppm, how to convert to percent and dose a tank.
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12 articles
- Chemistry4 min read
How to Work Out Gas Density From Pressure and Temperature
Gas density follows ρ = pM/(RT). Air at 101,325 Pa and 300 K is about 1.177 kg/m³, while CO₂ under the same conditions is roughly 1.79 kg/m³.
- Chemistry4 min read
Ideal Gas Pressure: Using P = nRT/V Correctly
Gas pressure follows P = nRT/V. Half a mole of gas in 10 L at 298 K presses at about 124 kPa, and the guide shows which units make that come out right.
- Chemistry5 min read
Molality Explained: Formula and Worked Example
Molality is moles of solute divided by kilograms of solvent: 0.5 mol in 2 kg is 0.25 mol/kg. See why it ignores temperature and how it differs from molarity.
- Chemistry5 min read
What Is Molarity? Formula, Examples and Dilution
Molarity is moles of solute per litre of finished solution: 0.75 mol in 1.5 L is 0.50 mol/L. Includes the dilution rule M1V1 = M2V2 with a worked case.
- Chemistry4 min read
Mole Fraction Explained With a Water–Ethanol Mix
Mole fraction is one component's moles divided by all moles present. See it worked on 36 g of water and 46 g of ethanol, giving 0.667 and 0.333.
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