Explain uses of magnesium hydroxide and calcium carbonate in neutralising acidity.

In the subtopic Group 2 applications, this AQA A-Level Chemistry 7405 learning objective focuses on explain uses of magnesium hydroxide and calcium carbonate in neutralising acidity. It belongs to Group 2, the alkaline earth metals, so revision should stay anchored to this exact subtopic rather than drifting into a generic GCSE-level chemistry summary. Approved keywords to use include magnesium hydroxide, acidity. Magnesium hydroxide. means a compound used to neutralise acidity, often found in antacids Avoid the mistake of students often confuse the roles of magnesium hydroxide and calcium carbonate in neutralising acidity, thinking they are interchangeable; instead, to clarify, magnesium hydroxide (Mg(OH)₂) is a strong base that reacts with acids to form water and a salt, while calcium carbonate (CaCO₃) reacts to produce carbon dioxide, water, and a salt. The reaction for magnesium hydroxide can be represented as: Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O. Here, substitution shows that 1 mole of magnesium hydroxide neutralises 2 moles of hydrochloric acid, resulting in 1 mole of magnesium chloride and 2 moles of water. The conclusion is that magnesium hydroxide is effective for neutralising acidity due to its strong basic properties For exam answers, remember that magnesium hydroxide (Mg(OH)₂) and calcium carbonate (CaCO₃) are commonly used to neutralise acidity in the stomach