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

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

a) Potassium oxide with water

First, we need to write down the reactants: potassium oxide (K₂O) and water (H₂O). Next, we identify the product: The potassium oxide will react with water to form potassium hydroxide (KOH). Now we balance the equation. We have 2 potassium ions on the left side, so we need 2 potassium ions on the right side, giving us: K₂O + H₂O → 2KOH

b) Diphosphorus trioxide with water

First, write down the reactants: diphosphorus trioxide (P₂O₃) and water (H₂O). Next, identify the product: Diphosphorus trioxide will react with water to form phosphorous acid (H₃PO₃). Now we balance the equation. We have 2 phosphorus and 3 oxygen atoms on both sides of the equation, so we need 6 hydrogen atoms on the right side: P₂O₃ + 3H₂O → 2H₃PO₃

c) Chromium(III) oxide with dilute hydrochloric acid

Write down the reactants: chromium(III) oxide (Cr₂O₃) and hydrochloric acid (HCl). Identify the products: Chromium(III) oxide reacts with hydrochloric acid to form chromium(III) chloride (CrCl₃) and water (H₂O). Next, we'll balance the equation. We have 2 chromium and 3 oxygen atoms on the left side, so we need 6 chlorine atoms on the right side to balance: Cr₂O₃ + 6HCl → 2CrCl₃ + 3H₂O

d) Selenium dioxide with aqueous potassium hydroxide

Write down the reactants: selenium dioxide (SeO₂) and potassium hydroxide (KOH). Identify the products: Selenium dioxide reacts with potassium hydroxide to form potassium selenite (K₂SeO₃) and water (H₂O). Now we balance the equation. We have 1 selenium and 2 oxygen atoms on both sides, so we need 2 potassium ions and 2 hydroxide ions on the right side: SeO₂ + 2KOH → K₂SeO₃ + H₂O

Key concepts

Balancing Equations

Balancing chemical equations is an essential skill in chemistry. When a chemical reaction occurs, it is represented by a chemical equation which describes the substances involved in the reaction. On the left side of the equation are the reactants, and on the right side are the products. However, to reflect the law of conservation of mass, the equation must be balanced. This means that the number of atoms for each element in the reactants side must equal the number in the products side. Here's how you can balance equations:

• Write down the unbalanced equation.
• List all the elements involved in the equation.
• Count the atoms of each element on both sides of the equation.
• Add coefficients (whole numbers in front of compounds) to balance the atoms.
• Iterate the process to ensure all atoms are balanced.

Balancing equations involves patience and practice, but it becomes intuitive with more experience.

Inorganic Chemistry

Inorganic chemistry is a branch of chemistry that deals with compounds lacking carbon-hydrogen bonds, categorized as 'non-organic'. This field covers a vast array of substances including metals, minerals, and organometallic compounds. Common topics in inorganic chemistry include:

• Acids and bases: Understanding how they react to form new compounds, often by ion exchange.
• Oxides: Compounds like chromium(III) oxide or selenium dioxide that frequently act as reactants in chemical reactions.
• Coordination chemistry: Study of chemical compounds with complex metallic frameworks.

Inorganic reactions often involve a transformation of basic continues, like the conversion of oxides or hydroxides, keeping the principles of stoichiometry intact. This makes understanding inorganic chemistry essential for tackling real-world problems.

Chemical Reactions

Chemical reactions are processes where substances, known as reactants, are transformed into different substances, called products. They are central to chemistry and are highly relevant in everyday life, occurring constantly around us. Here are key points about chemical reactions:

• Types: Include synthesis, decomposition, single replacement, and double replacement reactions. Each follows distinct pathways and principles.
• Energy Changes: Reactions either release energy (exothermic) or absorb energy (endothermic), affecting temperature and state of matter.
• Reaction Rate: Influenced by factors such as concentration, temperature, and the presence of catalysts, affecting how quickly a reaction occurs.

Understanding chemical reactions requires the ability to not only balance equations but also predict the changes in energy and states of matter involved. This knowledge forms the backbone of practical applications in industries like pharmaceuticals, agriculture, and environmental science.