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This applies to any gas that is at standard temperature and pressure. In grade 11 you will learn more about this and the gas laws.
A typical solution is made by dissolving some solid substance in a liquid. The amount of substance that is dissolved in a given volume of liquid is known as the concentration of the liquid. Mathematically, concentration (C) is defined as moles of solute (n) per unit volume (V) of solution.
For this equation, the units for volume are $\mathrm{dm}{}^{3}$ . Therefore, the unit of concentration is $\mathrm{mol}\xb7{\mathrm{dm}}^{-3}$ . When concentration is expressed in $\mathrm{mol}\xb7{\mathrm{dm}}^{-3}$ it is known as the molarity (M) of the solution. Molarity is the most common expression for concentration.
Concentration is a measure of the amount of solute that is dissolved in a given volume of liquid. It is measured in $\mathrm{mol}\xb7{\mathrm{dm}}^{-3}$ . Another term that is used for concentration is molarity (M)
If $\mathrm{3,5}\phantom{\rule{2pt}{0ex}}\mathrm{g}$ of sodium hydroxide (NaOH) is dissolved in $\mathrm{2,5}\phantom{\rule{2pt}{0ex}}{\mathrm{dm}}^{3}$ of water, what is the concentration of the solution in $\mathrm{mol}\xb7{\mathrm{dm}}^{-3}$ ?
The concentration of the solution is $\mathrm{0,035}\phantom{\rule{2pt}{0ex}}\mathrm{mol}\xb7{\mathrm{dm}}^{-3}$ or $\mathrm{0,035}\phantom{\rule{2pt}{0ex}}\mathrm{M}$
You have a $1\phantom{\rule{2pt}{0ex}}{\mathrm{dm}}^{3}$ container in which to prepare a solution of potassium permanganate ( $\mathrm{KMnO}{}_{4}$ ). What mass of $\mathrm{KMnO}{}_{4}$ is needed to make a solution with a concentration of $\mathrm{0,2}\phantom{\rule{2pt}{0ex}}\mathrm{M}$ ?
therefore
The mass of $\mathrm{KMnO}{}_{4}$ that is needed is $\mathrm{31,61}\phantom{\rule{2pt}{0ex}}\mathrm{g}$ .
How much sodium chloride (in g) will one need to prepare $500\phantom{\rule{2pt}{0ex}}{\mathrm{cm}}^{3}$ of solution with a concentration of $\mathrm{0,01}\phantom{\rule{2pt}{0ex}}\mathrm{M}$ ?
The mass of sodium chloride needed is $\mathrm{0,29}\phantom{\rule{2pt}{0ex}}\mathrm{g}$
Stoichiometry is the calculation of the quantities of reactants and products in chemical reactions. It is also the numerical relationship between reactants and products. In representing chemical change showed how to write balanced chemical equations. By knowing the ratios of substances in a reaction, it is possible to use stoichiometry to calculate the amount of either reactants or products that are involved in the reaction. The examples shown below will make this concept clearer.
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