1 - 6 Chemical formulae, equations and
calculations: part 2
Calculations involving gas volumes
● ***Avogadro’s law: equal volumes of gases at the same temperature and
atmospheric pressure contain equal numbers of molecules [vice versa]
● 1 mole of any gas occupies approximately 24 dm3 (24000 cm3/24 L) at room
temperature and pressure (rtp) (often called molar volume)
●
(RFM)
●
Solution concentrations
● Measured in g/dm3 or mol/dm3 (M)
● E.g.: 1 mol NaCl has mass of 58.5 g, there are 35.1 g in every dm3 of solution
mass (g)
*** No . of mol= }, 35.1/58.5 = 0.6 mol
mass of 1 mol(g)
There are 0.6 mol in every dm3 of solution, therefore concentration of NaCl = 0.6
mol/dm3
● *** No . of mol=volume of solution( dm3 )× concentration(mol /dm3 )
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calculations: part 2
Calculations involving gas volumes
● ***Avogadro’s law: equal volumes of gases at the same temperature and
atmospheric pressure contain equal numbers of molecules [vice versa]
● 1 mole of any gas occupies approximately 24 dm3 (24000 cm3/24 L) at room
temperature and pressure (rtp) (often called molar volume)
●
(RFM)
●
Solution concentrations
● Measured in g/dm3 or mol/dm3 (M)
● E.g.: 1 mol NaCl has mass of 58.5 g, there are 35.1 g in every dm3 of solution
mass (g)
*** No . of mol= }, 35.1/58.5 = 0.6 mol
mass of 1 mol(g)
There are 0.6 mol in every dm3 of solution, therefore concentration of NaCl = 0.6
mol/dm3
● *** No . of mol=volume of solution( dm3 )× concentration(mol /dm3 )
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