AQA A-level Chemistry Concentration and moles
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3. Concentration and moles
Avogadro's constant: 1 mole = 6.02 x 10²³ atoms/molecules/protons. To convert from moles to atoms (or reverse) use Avogadro's constant. Moles can also be calculated by using the pyramid (mass = moles x RFM).
A solution formed when a solute dissolves in a solvent has a concentration which can be calculted by dividing the mass of dissolved dolute in g by the volume of the solution in dm³ giving the concentration in g/dm³.
You can calculate the concentration in mol/dm³ of a solution by calculating the moles and dividing by the volume of the solution.
2g of NaOH is dissolved in 2 dm³ water. What is the concentration of the solution in mol/dm³?
A solution of HCl has a concentration of 8 g/dm³ is made. What is the volume of water you'd need to dissolve 0.002 kg of HCl in?
You are making a solution of HCl has a concentration of 2 mol/dm³. What is the volume of water you'd need to dissolve 0.5 mol NaOH in?
Calculate the number of particles in 2 mol of a substance?
200 cm³ dilute HCl contains 0.25 mol dissolved hydrogen chloride. What is the concentration of the acid in mol/dm³?
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