Final answer:
In 11th-grade chemistry, the molar volume of a gas is 22.4 dm³ per mole at STP, according to Avogadro's law. Molar concentration (Cm) is found using the formula Cm = n/V, where 'n' is the number of moles and 'V' is the volume in liters. The number of moles can be calculated from mass using molar mass.
Step-by-step explanation:
In 11th-grade chemistry, to find the molar volume and molar concentration (Cm) of a substance, you'll need to know a few key formulas. The molar volume of a gas at standard temperature and pressure (STP) is 22.4 dm³ per mole. This is derived from Avogadro's law, which states that one mole of any gas at STP occupies the same volume.
When calculating molar concentrations, you use the formula Cm = n/V, where 'Cm' is the molar concentration, 'n' is the number of moles, and 'V' is the volume of the solution in liters. If the number of moles is not given, you can calculate it from the mass using the molar mass of the substance: n = mass (g) / molar mass (g/mol).
For example, if we have to find the concentration of HCl dissolved in water, and we're given that 100 mL of HCl gas at 300 K and 100 kPa dissolves in 20 mL of water, we can convert the volume to liters and use the ideal gas law to find the number of moles of HCl. Once we have the number of moles, we can divide by the total volume of the solution to find the concentration.