Apply the mole concept to calculate the mass of reactants and products; amount of substance in moles; number of representative particles; and molar mass of atoms, ions, molecules and formula units. (Formula: moles (𝑛) = mass (m) molar mass (M))

Calculate the number of moles of magnesium carbonate, MgCO₃, in an 8.4 g sample. (Atomic masses: Mg = 24; C = 12; O = 16)

A laboratory technician requires \(1.50 \times 10^{24}\) molecules of glucose (\(\text{C}_6\text{H}_{12}\text{O}_6\)) to prepare a stock solution. (a) Calculate the amount of glucose, in moles, required. (2 marks) (b) Hence determine the mass of glucose, in grams, that must be weighed out. (2 marks)

Calcium carbonate (CaCO₃) decomposes when heated to produce calcium oxide and carbon dioxide. A student heats a sample containing 2.50 g of pure calcium carbonate. (a) Calculate the number of moles of calcium carbonate in the sample. (1 mark) (b) Using the molar mass of calcium oxide (CaO = 56 g/mol), determine the mass of calcium oxide produced if all the calcium carbonate decomposes completely. (1 mark) [Molar mass of CaCO₃ = 100 g/mol]

Calculate the concentration of the KOH(aq) solution if a 20.00 mL aliquot of aqueous potassium hydroxide (KOH) solution was titrated against an aqueous solution of 0.150 M sulfuric acid (H₂SO₄), requiring 15.00 mL of H₂SO₄ to reach the equivalence point. The balanced equation is: 2KOH(aq) + H₂SO₄(aq) → K₂SO₄(aq) + 2H₂O(l)