Write a balanced net ionic equation for the reaction of each of the following hydrides with water: (a) HI (b) KH.

Verified step by step guidance

Step 1: Identify the type of reaction that occurs when each hydride reacts with water. For HI, it is an acid-base reaction, and for KH, it is a hydrolysis reaction.

Step 2: Write the molecular equation for each reaction. For HI, the reaction with water is HI + H2O → H3O+ + I-. For KH, the reaction is KH + H2O → KOH + H2.

Step 3: Break down the molecular equations into complete ionic equations. For HI, it becomes H+ + I- + H2O → H3O+ + I-. For KH, it becomes K+ + H- + H2O → K+ + OH- + H2.

Step 4: Identify and cancel out the spectator ions that appear on both sides of the ionic equations. For HI, the I- ions are spectators. For KH, the K+ ions are spectators.

Step 5: Write the net ionic equations by removing the spectator ions. For HI, the net ionic equation is H+ + H2O → H3O+. For KH, the net ionic equation is H- + H2O → OH- + H2.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Net Ionic Equations

A net ionic equation represents the chemical species that are involved in a reaction, excluding spectator ions. It focuses on the actual chemical change occurring in the solution. To write a net ionic equation, one must first write the balanced molecular equation, then dissociate the soluble ionic compounds into their ions, and finally eliminate the spectator ions to reveal the net ionic reaction.

Acid-Base Reactions

Acid-base reactions involve the transfer of protons (H⁺ ions) between reactants. In the case of HI, a strong acid, it dissociates completely in water to produce H⁺ and I⁻ ions. For KH, a strong base, it dissociates to yield K⁺ and OH⁻ ions. Understanding these dissociations is crucial for determining the products of the reactions with water.

Hydride Reactions with Water

Hydrides, such as HI and KH, react with water to form acids or bases. HI reacts with water to produce hydronium ions (H₃O⁺) and iodide ions (I⁻), while KH reacts to produce potassium ions (K⁺) and hydroxide ions (OH⁻). Recognizing the nature of these reactions helps in predicting the products and writing the corresponding net ionic equations.

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