Mole calculations - Mole, RMM, concentration of a solution, chemical equations , moles of gases PDF

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Mole, RMM, concentration of a solution, chemical equations , moles of gases...

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Mole calculations The mole: This is an amount of any substance that contains 6.02 x 1023 particles (Avogadro’s constant). It also does not matter what type of particles they are. Number of particles: No. of particles = no. moles x Avogadro’s constant E.g.

How many ions are in 0.4 moles of copper ions (Cu2+)? Answer: 0.4 x 6.02 x 1023 = 2.41 x 1023 mol

Moles and relative molecular mass: One mole of a substance has a mass that is the same as its relative molecular mass in grams. E.g. One mole of CaO has a mass of 56.1 g No. of moles are able to be calculated from the mass of a substance and its Mr. No. of moles = mass / Mr Units: g/mol-1 Concentration of a solution: This is how many moles are dissolved in 1 dm3. The unit is mol dm-3. The molarity of a solution is the same as the concentration. No. of moles = conc (mol dm-3) x volume (dm3) When the volume is in cm3, divide by 1000. Chemical equations: Balanced equations must have the same number of atoms on either side. Sometimes state symbols are used in these equations. E.g. 2KOH (aq) + H2SO4 (aq)  K2SO4 (aq) + 2H2O (l) Moles of gases: This can be calculated using the ideal gas equation. pV = nRT p = pressure (Pa) V = volume (m3) n = no. of moles R = 8.31 J K-1 mol -1 (the gas constant) T = temperature (K) To convert temperature from C to K, you add 273. Calculations based on chemical equations: This is usually to work out how much reactant to add or how much product should be obtained....