Chemical Reactions and Equations

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A chemical reaction is a process where substances change their chemical composition to form new substances. Two key observations that indicate a chemical reaction has occurred are: (1) Change in color…

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Word equation: Magnesium + Oxygen → Magnesium oxide Chemical equation (skeletal): Mg + O₂ → MgO Balanced chemical equation: 2Mg + O₂ → 2MgO Observation: Magnesium burns with a dazzling white flame,…

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The law of conservation of mass states that mass can neither be created nor destroyed in a chemical reaction. Therefore, the total mass of reactants must equal the total mass of products. In balancing…

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Balanced equation: 3Fe + 4H₂O → Fe₃O₄ + 4H₂ Step-by-step balancing: 1. Fe₃O₄ has the most atoms, so start there 2. Balance oxygen: 4 oxygen atoms on right → need 4H₂O on left 3. Balance hydrogen: 4H₂…

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(s) = Solid state - like Fe₃O₄(s) in 3Fe(s) + 4H₂O(g) → Fe₃O₄(s) + 4H₂(g) (l) = Liquid state - like H₂O(l) when water is in liquid form (g) = Gaseous state - like H₂(g) for hydrogen gas (aq) = Aqueous…

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A combination reaction occurs when two or more substances (elements or compounds) combine to form a single new product. Formula: A + B → C Example 1: Burning of coal - C(s) + O₂(g) → CO₂(g) Example 2…

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The blue color fades because copper ions (Cu²⁺) from the solution are displaced by iron metal, which is more reactive. As Cu²⁺ ions are consumed, the solution becomes less blue. Balanced equation: Fe…

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Decomposition reactions require energy input to break down a compound into simpler products. The energy source differs: 1. Thermal decomposition (heat): - CaCO₃(s) --Heat-→ CaO(s) + CO₂(g) (limest…