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Junior high school chemistry problem: what is the calculation formula of solution dilution?
Formula: W=M mass /M solution × 100% Remember, no matter how much water is added, the solute mass is constant, and the solution mass is the original solution mass+the added water mass.

In addition, some other formulas for calculating the solution are attached:

1, mass fraction of solute = solute mass/solution mass × 100% = solute mass/(solute mass+solvent mass) × 100%.

2. Dilution and concentration of solution M concentration× A% concentration =M dilution× B% dilution =(M concentration+increased solvent mass )× B% dilution.

3. The mixture of two solutions with different relative solute mass fractions is m concentration× a% concentration +M dilution× b% dilution =(M concentration +M dilution )× c%.

4. The mass of solute in solution = mass of solution × mass fraction of solute in solution = volume of solution × density of solution.

The most common solvent in daily life is water. The so-called organic solvent is an organic compound solvent containing carbon atoms. Solvents usually have a low boiling point and are easy to volatilize. Or it can be removed by distillation, leaving dissolved substances.

Therefore, the solvent cannot react chemically with the solute. They must keep a low profile. Solvents can extract soluble compounds from the mixture, and the most common example is to brew coffee or tea with hot water. Solvents are usually transparent and colorless liquids, and most of them have unique smells.

Extended data:

A substance dissolved in a solution by a solvent. Solute can be solid (such as sugar dissolved in water), liquid (such as alcohol dissolved in water) and gas (such as carbon dioxide dissolved in carbonated drinks). In fact, solute and solvent are just a set of relative concepts in solution. Generally speaking, relatively more substances are called solvents and relatively less substances are called solutes.

Unsaturated solution can be converted into saturated solution by increasing solute (applicable to all solutions) or decreasing temperature (applicable to most solutes whose solubility increases with the increase of temperature, otherwise the temperature must be increased, such as lime water) and evaporating solvent (when the solvent is liquid).

Saturated solution can be converted into unsaturated solution by increasing solvent (applicable to all solutions) or increasing temperature (applicable to most solutes whose solubility increases with temperature, and vice versa, such as lime water).

The regular solution is a solution closer to the actual solution. Its formation is consistent with the ideal solution, but the mixed entropy is not equal to zero. Thermodynamic laws derived from regular solutions are widely used in non-electrolyte solutions, especially many alloy solutions. Therefore, the normal solution theory is very important to metallurgy and metal materials science.

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