Acids and Non-Metallic Oxides

Basic oxides

Salt and water

A salt and water

<p>They react with the metal to form poisonous salts.</p> Signup and view all the answers

<p>Hydrogen gas</p> Signup and view all the answers

<p>Bring a burning candle near the gas. It will extinguish with a 'pop' sound.</p> Signup and view all the answers

<p>$CaCl_2$</p> Signup and view all the answers

<p>Hydrogen ion ($H^+$)</p> Signup and view all the answers

<p>No</p> Signup and view all the answers

<p>Curd and sour substances contain acids that can react with brass and copper, leading to the formation of toxic metallic compounds, which can contaminate the food and cause health issues.</p> Signup and view all the answers

<p>Hydrogen gas is usually liberated. For example: $Zn(s) + 2HCl(aq) \rightarrow ZnCl_2(aq) + H_2(g)$. To test for hydrogen, bring a burning splint near the gas; it will burn with a pop sound.</p> Signup and view all the answers

<p>$CaCO_3(s) + 2HCl(aq) \rightarrow CaCl_2(aq) + H_2O(l) + CO_2(g)$</p> Signup and view all the answers

<p>Hydrogen is common to all acids. This was determined by observing that all acids generate hydrogen gas when reacting with metals.</p> Signup and view all the answers

<p>Metallic oxides react with acids to form salt and water, similar to the reaction between a base and an acid. This behavior leads to their classification as basic oxides.</p> Signup and view all the answers

<p>Non-metallic oxides react with bases to produce salt and water, mirroring the reaction of an acid with a base. This behavior confirms their acidic nature.</p> Signup and view all the answers

<p>Glucose and alcohol contain hydrogen but do not dissociate to produce $H^+$ ions in aqueous solutions, which is necessary for acidic behavior.</p> Signup and view all the answers

<p>Tap water contains impurities and ions that can conduct electricity, leading to inaccurate results when testing the conductivity of acid or base solutions. Distilled water is pure and does not contain such impurities.</p> Signup and view all the answers

<p>No, a solution that turns litmus paper red is acidic. Acids turn blue litmus paper red.</p> Signup and view all the answers

<p>Both will produce a salt and water. If one were to titrate, you would observe that the pH at the equivalence points would vary. Strong acid/strong base will have a neutral pH, strong acid/weak base would have a pH below 7, and a weak acid/strong base would have a pH above 7.</p> Signup and view all the answers

<p>Metallic oxides react with acids to form salts and water, which is analogous to the reaction between a base and an acid. This neutralization-like behavior leads to their classification as basic oxides.</p> Signup and view all the answers

<p>Reacting carbon dioxide (a non-metallic oxide) with calcium hydroxide (lime water) results in the formation of calcium carbonate (a salt) and water. This reaction mirrors a neutralization, confirming the acidic nature of non-metallic oxides.</p> Signup and view all the answers

<p>Curd and sour substances contain acids that can react with brass and copper, leading to the formation of toxic metallic compounds. This can cause food poisoning and corrosion of the vessels.</p> Signup and view all the answers

<p>Hydrogen gas is usually liberated. To test for its presence, bring a burning splint near the gas; hydrogen will burn with a pop sound.</p> Signup and view all the answers

<p>CaCO3(s) + 2HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g)</p> Signup and view all the answers

<p>Hydrogen is considered the unifying factor. Acids generate hydrogen ions (H+) when dissolved in water, which contributes to their acidic properties.</p> Signup and view all the answers

<p>Materials: Glucose, alcohol, hydrochloric acid, sulphuric acid, beaker, cork, nails, power source, lightbulb. Procedure: Dissolve each substance in water. Test conductivity attaching leads to nails submersed in solutions. Observation: Acids will conduct electricity, lighting the lightbulb, while glucose and alcohol will not.</p> Signup and view all the answers

<p>HCl is a strong acid, ionizing completely in solution, while acetic acid is a weak acid, ionizing partially. Thus at the same concentration, HCl will have a greater concentration of hydronium ions and will therefore have a greater effect on litmus paper, and faster reaction rate with metals..</p> Signup and view all the answers

<p>Measure the electrical conductivity/current of the solution. A strong acid will dissociate more readily than a weak acid, creating more ions in the solution and a higher current. Also, one could analyze the concentration of hydrogen ions using a more precise method or titrate with a standard base.</p> Signup and view all the answers

<p>A base is a substance capable of neutralizing an acid. An alkali is a base that is soluble in water. For example, copper oxide is a base but not an alkali as it is insoluble in water, whereas sodium hydroxide is both a base and an alkali because it dissolves in water.</p> Signup and view all the answers

<p>The standard reduction potentials of copper and zinc (primary constituents of brass) are higher than that of hydrogen. Acids in curd can corrode these metals, leading to the formation of metallic salts which are toxic and render the food unsafe for consumption. This is driven by the Gibbs free energy change being negative for the corrosion process.</p> Signup and view all the answers

<p>Collect the evolved gas in a eudiometer tube over water. Measure the volume of the gas at known temperature and pressure (corrected for water vapor pressure). Use the ideal gas law ($PV = nRT$) to find the number of moles of hydrogen gas. Relate this to the moles of metal reacted via stoichiometry, and from the mass of metal used, calculate the molar mass.</p> Signup and view all the answers

<p>The gas is carbon dioxide. CO2 extinguishes flames primarily by displacing oxygen, effectively smothering the fire. This is a physical mechanism. Chemically, at high temperatures CO2 can dissociate into CO and O, but this is not the primary mechanism for extinguishing a candle flame.</p> Signup and view all the answers

<p>The common property is due to the presence of hydronium ions ($H_3O^+$). The concentration of these ions determines the acidity. Similar chemical properties arise because reactions with acids often involve $H_3O^+$. The common ion effect, where the presence of a common ion decreases the ionization of a weak acid, explains the varying strengths of acids.</p> Signup and view all the answers

<p>Perform cyclic voltammetry on both acids in a non-aqueous solvent with a suitable supporting electrolyte. Strong acids will show a more pronounced reduction peak for $H^+$ due to their complete dissociation, yielding a higher current. Weak acids will exhibit a less distinct peak due to incomplete dissociation. Compare the peak currents to determine the relative degrees of dissociation.</p> Signup and view all the answers

<p>First, analyze the oxide using X-ray diffraction (XRD) to determine its crystalline structure. Then, dissolve the oxide separately in strong acid and strong base, and analyze the resulting solutions using inductively coupled plasma mass spectrometry (ICP-MS) to identify the dissolved metal ions. Raman spectroscopy can provide insights into the vibrational modes and bonding characteristics, confirming the presence of relevant metal-oxygen bonds. Compare the spectra of the original oxide and the generated ions. Finally, perform pH titrations on the oxide solutions to quantify acid-base behavior.</p> Signup and view all the answers

<p>React the non-metallic oxide with $H_2^{18}O$ and analyze the resulting hydrated oxide using mass spectrometry. The presence of $^{18}O$ in different positions within the oxide structure will reveal the extent of water incorporation and the formation of hydroxyl groups. Measure the acidity of the hydrate, comparing with the anhydrous oxide using pH measurements. Compare the MS and pH of both oxide types. Correlate the degree of hydration and isotope location to acidity.</p> Signup and view all the answers

<p>First use electrospray ionization mass spectrometry (ESI-MS) in positive and negative ion modes, scanning a wide mass-to-charge (m/z) range (e.g., 100-2000 m/z) to identify the molecular ions and fragmentation patterns of different isomers. Complement this with NMR spectroscopy, utilizing both 1H and 13C NMR. For 1H NMR, assess the chemical shift and coupling patterns to differentiate the arrangement of protons in the isomer. For 13C NMR, record spectra with and without proton decoupling to glean chemical environment details. If relevant, use isotopic enrichment (e.g. $^{13}$C) to get better signal resolution. Correlate the MS fragmentation patterns to NMR chemical shifts to assign specific structures to each peak.</p> Signup and view all the answers

<p>Use Density Functional Theory (DFT) calculations with appropriate basis sets (e.g., hybrid functionals like B3LYP or more advanced ones like ωB97X-D) to optimize the molecular structures of the superacid and its conjugate base. Calculate the gas-phase proton affinity and deprotonation energy. Perform Natural Bond Orbital (NBO) analysis to determine the charge distribution in the superacid and the stabilization energies associated with proton donation. Analyze the HOMO and LUMO energies to understand the ease of electron acceptance upon deprotonation. Finally, assess the influence of solvent effects using implicit solvation models (e.g., PCM or SMD).</p> Signup and view all the answers

<p>Use time-resolved infrared (TR-IR) spectroscopy to monitor vibrational modes associated with the acid, base, and protonated base over time. Initiate the proton transfer reaction using a laser pulse and record the changes in IR absorption as a function of time. Identify and track the appearance of new vibrational modes corresponding to the protonated base ($BH^+$) and the disappearance of modes associated with the acid ($AH$). Analyze the kinetics of these changes (e.g., using kinetic modeling) to determine the rate constants for proton transfer and to identify any intermediate species such as a proton-bound complex ($A...H...B$). Use isotopic substitution (e.g., deuterium) to confirm proton involvement. This would elucidate whether the mechanism involves direct proton transfer or requires intermediate steps.</p> Signup and view all the answers

Metallic oxides that react with acids to form salts and water.

Non-metallic oxides react with bases to produce salts and water, showing acidity.

When an acid reacts with a metal, hydrogen gas is usually produced.

The release of gas bubbles in a liquid, often observed when acids react with metals.

An equation showing equal numbers of each type of atom on both sides.

Calcium hydroxide reacts with carbon dioxide to form calcium carbonate and water.

A burning candle extinguished indicates the presence of hydrogen gas.

All acids generate hydrogen gas upon reacting with metals.

Both exhibit similar chemical properties, especially in water.

Experiments with various compounds to test for acidity or properties.

The result of reactions between acids and bases, producing salts and water.

Compounds formed from metals and oxygen, react with acids to form salts.

A chemical reaction between an acid and base to form salt and water.

Carbon dioxide reacts with calcium hydroxide to produce calcium carbonate and water.

The production of gas bubbles during a reaction, often from acids reacting with metals.

A lit candle will extinguish in the presence of hydrogen gas.

All acids produce hydrogen gas when reacting with metals.

Using various compounds to test their acidic properties through reactions.

Curd and sour substances can react with brass and copper, causing harmful effects.

Acids in solution display properties like sourness and conductivity.

Non-metallic oxides that react with bases to produce salts.

A base that reacts with carbon dioxide to form calcium carbonate and water.

Gas bubbles produced when an acid reacts with a metal.

All acids generate hydrogen gas when reacting with metals.

Equating the number of atoms on both sides of a reaction equation.

Hydrogen gas can extinguish a burning candle when present.

Curd and sour substances can react with brass and copper vessels.

Hydrogen is a common feature in the chemistry of acids.

Acids react similarly with various substances, demonstrating their properties.

Oxides of non-metals that react with bases to yield salts and water.

When acids react with metals, hydrogen gas is produced.

Demonstrates how non-metallic oxides can be acidic.

Gas bubbles produced during a chemical reaction, often with acids.

A test for hydrogen gas, where it snuffs out a flame.

Curd and sour substances can react with these metals, causing danger.

All acids generate hydrogen ions, which are key to their properties.

Ensuring equal numbers of atoms in a chemical reaction equation.