Question

Write balanced equations for the following reactions: (a) potassium oxide with water, (b) diphosphorus trioxide with water, (c) chromium(III) oxide with dilute hydrochloric acid, (d) selenium dioxide with aqueous potassium hydroxide.

Short answer

The balanced equations for the given reactions are: a) \( K_2O + H_2O \rightarrow 2KOH \) b) \( P_2O_3 + 3H_2O \rightarrow 2H_3PO_3 \) c) \( Cr_2O_3 + 6HCl \rightarrow 2CrCl_3 + 3H_2O \) d) \( SeO_2 + 2KOH \rightarrow K_2SeO_3 + H_2O \)

Step-by-step solution

Reaction A - Potassium Oxide with Water

1. Write the formulas for the reactants and products: Potassium oxide (K2O) reacts with water (H2O) to form potassium hydroxide (KOH). 2. Balance the equation: For this equation, we need equal numbers of each element on both sides. \( K_2O + H_2O \rightarrow 2KOH \) Now the equation is balanced: there are two potassium atoms, two oxygen atoms, and two hydrogen atoms on both the reactant and product sides.

Reaction B - Diphosphorus Trioxide with Water

1. Write the formulas for the reactants and products: Diphosphorus trioxide (P2O3) reacts with water (H2O) to form phosphoric acid (H3PO3). 2. Balance the equation: For this equation, we need equal numbers of each element on both sides. \( P_2O_3 + 3H_2O \rightarrow 2H_3PO_3 \) Now the equation is balanced: there are two phosphorus atoms, six oxygen atoms, and six hydrogen atoms on both the reactant and product sides.

Reaction C - Chromium (III) Oxide with Dilute Hydrochloric Acid

1. Write the formulas for the reactants and products: Chromium (III) oxide (Cr2O3) reacts with hydrochloric acid (HCl) to form chromium (III) chloride (CrCl3) and water (H2O). 2. Balance the equation: For this equation, we need equal numbers of each element on both sides. \( Cr_2O_3 + 6HCl \rightarrow 2CrCl_3 + 3H_2O \) Now the equation is balanced: there are two chromium atoms, three oxygen atoms, and six hydrogen atoms, and six chlorine atoms on both the reactant and product sides.

Reaction D - Selenium Dioxide with Aqueous Potassium Hydroxide

1. Write the formulas for the reactants and products: Selenium dioxide (SeO2) reacts with aqueous potassium hydroxide (KOH) to form potassium selenite (K2SeO3) and water (H2O). 2. Balance the equation: For this equation, we need equal numbers of each element on both sides. \( SeO_2 + 2KOH \rightarrow K_2SeO_3 + H_2O \) Now the equation is balanced: there is one selenium atom, three oxygen atoms, two potassium atoms, and two hydrogen atoms on both the reactant and product sides.