Acids and Water Solutions Activity

Ions

H+ (hydrogen ion)

Flow of electric current

<p>H3O+</p> Signup and view all the answers

<p>Cl-</p> Signup and view all the answers

<p>Aqueous (in water)</p> Signup and view all the answers

<p>Na+ and OH-</p> Signup and view all the answers

<p>To dry the gas</p> Signup and view all the answers

<p>H+(aq) is hydrated</p> Signup and view all the answers

<p>Glucose and alcohol</p> Signup and view all the answers

<p>Glucose and alcohol do not dissociate into ions in solution, unlike acids which produce ions like H+ that carry electric current.</p> Signup and view all the answers

<p>Hydrogen ions (H+) are responsible for the acidic properties of a solution. They are released when acids dissolve in water.</p> Signup and view all the answers

<p>Dry litmus paper tests for the presence of dry HCl gas, which does not exhibit acidic properties without water. Wet litmus paper tests for the presence of H+ ions, which form when HCl gas dissolves in water, thus showing acidic properties.</p> Signup and view all the answers

<p>Hydrogen ions (H+) combine with water molecules to form hydronium ions (H3O+), which is how they exist in aqueous solution.</p> Signup and view all the answers

<p>H+ + H2O → H3O+</p> Signup and view all the answers

<p>When NaOH is dissolved in water, it dissociates into sodium ions ($Na^+$) and hydroxide ions ($OH^-$).</p> Signup and view all the answers

<p>Water is required to stabilize the $H^+$ ions by forming hydronium ions ($H_3O^+$). Without water, the $H^+$ ions cannot be effectively separated from $Cl^-$ ions.</p> Signup and view all the answers

<p>$H^+$ and $CH_3COO^-$ ions would be primarily responsible for carrying the electric current.</p> Signup and view all the answers

<p>Pass the evolved gas through a guard tube containing calcium chloride to remove any moisture before testing with litmus paper.</p> Signup and view all the answers

<p>The wet litmus paper would turn blue because ammonia gas reacts with water to form ammonium ions ($NH_4^+$) and hydroxide ions ($OH^-$), making the solution alkaline.</p> Signup and view all the answers

<p>Glucose and alcohol do not dissociate into ions in solution, hence they cannot conduct electicity unlike acids.</p> Signup and view all the answers

<p>$NaOH(s) + H_2O(l) \rightarrow Na^+(aq) + OH^-(aq)$</p> Signup and view all the answers

<p>Wet litmus paper is needed because HCl needs to dissociate into ions (H+ and Cl-) to show acidic properties on the litmus paper.</p> Signup and view all the answers

<p>Hydrogen ions ($H^+$) are highly reactive and cannot exist alone in water. They bond with water molecules to form hydronium ions ($H_3O^+$).</p> Signup and view all the answers

<p>A higher concentration of $H^+$ ions in an acid solution will increase the intensity of the bulb's glow due to a greater flow of electric current.</p> Signup and view all the answers

<p>Concentrated sulfuric acid is a dehydrating agent and helps to drive the reaction forward by removing water, promoting the release of HCl gas.</p> Signup and view all the answers

<p>Use a conductivity meter to measure the conductivity of solutions of equal concentration at the same temperature.</p> Signup and view all the answers

<p>The bulb's glow would be dimmer with acetic acid because it is a weak acid and only partially ionizes, resulting in fewer ions to carry the electric current.</p> Signup and view all the answers

<p>A weak acid in water establishes a dynamic equilibrium between the unionized acid molecules and the ions formed, with continuous forward and reverse reactions.</p> Signup and view all the answers

<p>Measure the pH of equimolar solutions of NaOH and $NH_3$. NaOH will have a higher pH due to its complete dissociation, producing more hydroxide ($OH^-$) ions.</p> Signup and view all the answers

<p>The dissociation of HCl in hexane is thermodynamically unfavorable due to low solvation energy of ions in nonpolar solvent. Water can stabilize ions by making them hydrated via ion-dipole interactions. Hexane cannot.</p> Signup and view all the answers

<p>The buffering action is based on the equilibrium between the weak acid and its conjugate base, governed by the Henderson-Hasselbalch equation. The solution's pH will not change dramatically upon addition of small quantities of acid or base because the weak acid and conjugate base resist changes to this equilibrium. The equation is $pH = pKa + log([A-]/[HA])$. Temperature changes affects this equilibrium by changing the $pK_a$.</p> Signup and view all the answers

<p>While autoionization is major, trace ionic impurities can also contribute to the electrical conductivity of pure water. Measure the conductivity of water purified by multiple distillation steps and compare that conductivity to the theoretical conductivity calculated from the autoionization constant ($K_w$).</p> Signup and view all the answers

<p>If the endpoint is overshot in the titration, the determined concentration of the $HClO_4$ will be <em>underestimated</em>. The excess $NaOH$ added beyond the true equivalence point leads to a larger volume of $NaOH$ used in the calculation, which results in a calculated lower concentration of the $HClO_4$</p> Signup and view all the answers

<p>Experimental protocol: 1. Prepare a solution of the pure weak acid ($HA$) of known concentration ($C$). 2. Measure the conductivity ($\kappa$) of the solution using a conductivity meter. 3. Determine the molar conductivity ($\Lambda_m$) using the formula $\Lambda_m = \kappa / C$. 4. Determine the limiting molar conductivity ($\Lambda_m^0$) using extrapolation or literature values. 5. Calculate the degree of dissociation ($\alpha$) using the formula $\alpha = \Lambda_m / \Lambda_m^0$.</p> Signup and view all the answers

<p>The common ion effect decreases the solubility of a sparingly soluble salt. The solubility product ($K_{sp}$) represents the equilibrium constant for the dissolution of the salt ($AgCl(s) \rightleftharpoons Ag^+(aq) + Cl^-(aq)$). $K_{sp} = [Ag^+][Cl^-]$. The presence of additional $Cl^-$ from $NaCl$ shifts the equilibrium to the left, reducing the concentration of $Ag^+$ and reducing the solubility of $AgCl$.</p> Signup and view all the answers

<p>If the successive acid dissociation constants differ by several orders of magnitude (e.g., $K_{a1} &gt;&gt; K_{a2} &gt;&gt; K_{a3}$), we can often approximate the pH of a solution of the polyprotic acid by considering only the first dissociation step.</p> Signup and view all the answers

<p>Electrochemical experiment: create a half cell using the solid metal oxide sample as the electrode material. Expose the electrode to different protic and aprotic acids. Measure open circuit potential changes upon exposure to different acids. Distinguish between Bronsted and Lewis acidity: Bronsted acids will influence the electrical double layer due to proton transfer. Lewis acids will coordinate with surface oxygen atoms, changing the electronic structure. The electrochemical response is a direct indication of the type of acidity present.</p> Signup and view all the answers

<p>Consider liquid ammonia ($NH_3$) as an alternative solvent system. In liquid ammonia, an acid would be defined as a substance that increases the concentration of $NH_4^+$ ions, while a base would be a substance that increases the concentration of $NH_2^-$ ions. Practical challenges: Ammonia can be toxic, and needs special handling for the experiment.</p> Signup and view all the answers

<p>Microfluidic analysis for trace sample: 1. Chemically derivatize the unknown acid with a fluorescent tag, using reagents with amine groups. 2. Use fluorescence spectroscopy to precisely measure the concentration based on the fluorescent signals. High sensitivity is key, and the spectroscopic reading can determine concentration of the acid. 3. Analyze using UV-Vis spectroscopy and compare data to a spectral library.</p> Signup and view all the answers

<p>Glucose and alcohol do not dissociate into ions in solution, hence no charge carriers.</p> Signup and view all the answers

<p>Hydrogen ion, H+</p> Signup and view all the answers

<p>H+ + H2O → H3O+</p> Signup and view all the answers

<p>Dry HCl gas lacks H+ ions for acidic properties; water is needed to produce them.</p> Signup and view all the answers

<p>Cation: H+, Anion: $SO_4^{2-}$</p> Signup and view all the answers

<p>Sodium ions (Na+) and hydroxide ions (OH-)</p> Signup and view all the answers

<p>HCl gas; it turns wet blue litmus paper red.</p> Signup and view all the answers

<p>Calcium chloride absorbs moisture, ensuring the HCl gas remains dry.</p> Signup and view all the answers

<p>0.1 M HCl, because it is a strong acid and dissociates more completely into ions.</p> Signup and view all the answers

<p>The hydrochloric acid (HCl) solution, because as a strong acid, it provides a higher concentration of $H^+$ ions, which are reduced to form hydrogen gas at the cathode.</p> Signup and view all the answers

Acids allow electric current to flow due to ion presence.

Acids produce hydrogen ions (H+) and anions in solution.

In aqueous solutions, HCl splits into H3O+ and Cl–.

Hydronium ion is H3O+, where H+ combines with water.

Glucose and alcohol solutions do not conduct electricity.

NaOH dissociates into Na+ and OH– when dissolved in water.

A concentrated acid with NaCl produces gas, indicating acid behavior.

Testing dry HCl gas reveals its acidic nature through litmus.

H+ ions form H3O+ when in presence of water.

Acids produce ions only when dissolved in water.

HCl gas produces hydrogen ions when dissolved in water.

Acids produce H+ ions and anions like Cl– in water.

Water is necessary for hydrogen ions to separate from acids.

Sodium hydroxide produces Na+ and OH– when dissolved in water.

Glucose and alcohol do not conduct electricity due to lack of ions.

Mixing NaCl with concentrated acid can produce a gas, indicating acid behavior.

Dry HCl gas will change the color of wet litmus paper, showing acidity.

H+ ions combine with water to form hydronium ions (H3O+).

A glowing bulb indicates electric current flow through an acidic solution.

Acids conduct electricity because they produce ions; bases behave similarly.

Acids enable electricity flow via ion movement in solutions.

Acids contain H+ as cations along with various anions.

HCl dissociates into H3O+ and Cl- in water.

Bases, like NaOH, dissociate into ions when dissolved in water.

Mixing NaCl with concentrated acid produces gas, indicating reactivity.

Testing litmus paper reveals gas acidity from dry HCl gas.

H+ ions form hydronium (H3O+) with water molecules.

Acids produce H3O+ ions exclusively in aqueous solutions.

Alcohols do not conduct electricity due to lack of ions.

Acids conduct electricity due to ion presence in solution.

Water is necessary for the dissociation of acids into ions.

A glowing bulb indicates electric current flowing through acidic solutions.

Testing HCl gas with litmus shows its acidic nature.

Hydronium ion (H3O+) forms when H+ combines with water.

Bases like NaOH produce Na+ and OH- when dissolved.

Reacting NaCl with concentrated sulfuric acid produces gas.

Alcohol solutions do not conduct electricity due to lack of ions.

Dry HCl gas has acidic properties confirmed by litmus testing.

Acids split into H+ ions and anions when in solution.

Acids produce ions only when dissolved in water.

Litmus paper changes color when testing acidic solutions or gases.

Hydrogen ions (H+) require water to exist as hydronium (H3O+).

Adding concentrated acid to NaCl can produce gas, indicating acidity.

Solutions like HCl produce ions when mixed with water, confirming acidity.

Bases dissociate into cations and hydroxide ions (OH-) in water.