Question

Write a balanced equation for each reaction: (a) Thermal decomposition of witherite (barium carbonate) (b) Neutralization of stomach acid (HCI) by milk of magnesia (magnesium hydroxide)

Short answer

(a) \(\text{BaCO}_{3(s)} \rightarrow \text{BaO}_{(s)} + \text{CO}_{2(g)}\); (b) \(2\text{HCl}_{(aq)} + \text{Mg(OH)}_{2(s)} \rightarrow \text{MgCl}_{2(aq)} + 2\text{H}_{2}\text{O}_{(l)}\).

Step-by-step solution

Understand Thermal Decomposition

Thermal decomposition occurs when a compound breaks down into simpler substances when heated. For witherite (barium carbonate), the equation involves BaCO₃ decomposing to form barium oxide (BaO) and carbon dioxide (CO₂).

Write the Decomposition Equation

Write down the decomposition reaction for barium carbonate:\[\text{BaCO}_{3(s)} \rightarrow \text{BaO}_{(s)} + \text{CO}_{2(g)}\]Ensure each element is balanced on both sides of the equation.

Understand Neutralization Reaction

Neutralization is a chemical reaction between an acid and a base that produces water and a salt. The reaction between hydrochloric acid (HCl) and magnesium hydroxide (Mg(OH)₂) involves these compounds.

Write the Neutralization Equation

Write the balanced neutralization equation for HCl and Mg(OH)₂:\[2\text{HCl}_{(aq)} + \text{Mg(OH)}_{2(s)} \rightarrow \text{MgCl}_{2(aq)} + 2\text{H}_{2}\text{O}_{(l)}\]Ensure each element is balanced on both sides of the equation.

Key concepts

Thermal Decomposition

Thermal decomposition is a type of chemical reaction where a compound breaks down into simpler substances when it is heated. This process requires energy in the form of heat. One common example is the decomposition of witherite, or barium carbonate (BaCO₃). When barium carbonate is heated, it splits into barium oxide (BaO) and carbon dioxide (CO₂). Here is the balanced equation for the reaction:\[ \text{BaCO}_{3(s)} \rightarrow \text{BaO}_{(s)} + \text{CO}_{2(g)} \]In this equation, the subscript \