Quantitive chemistry

• Quantitative Chemistry involves calculating masses, moles, and concentrations in chemical reactions
• Avogadro's constant is 6.02 x 10^23, representing the number of atoms or molecules in one mole
• Percentage by mass is calculated by dividing the mass of a specific element in a compound by the total mass of the compound and multiplying by 100
• Balancing chemical equations requires ensuring that the number of atoms on both sides of the equation is equal
• In chemical reactions, the total mass of the products must equal the total mass of the reactants, demonstrating the law of conservation of mass
• Metal ions in Group 1 have a +1 charge, Group 2 have a +2 charge, and Group 3 have a +3 charge
• Non-metal ions in Group 6 have a -2 charge, and Group 7 have a -1 charge
• Positive ions are formed by metals, while negative ions are formed by non-metals
• To balance equations, the number of atoms on each side of the equation must be the same
• For example, in the reaction: Mg + Cl₂ → MgCl₂, 1 atom of Mg reacts with 1 molecule of Cl₂ to form 1 molecule of MgCl₂