Acids, Bases, and Salts Quiz

Sour

Red

Blue

<p>Turmeric</p> Signup and view all the answers

<p>Synthetic</p> Signup and view all the answers

<p>Lichen</p> Signup and view all the answers

<p>Purple</p> Signup and view all the answers

<p>Hydrangea</p> Signup and view all the answers

<p>Basic</p> Signup and view all the answers

<p>Distilled water is free from all ionic impurities, hence it is a non-conductor of electricity. Rain water, being a form of natural water, dissolves acidic gases from the air and forms ionic compounds, and hence it conducts electricity.</p> Signup and view all the answers

<p>A pH of 13 indicates a strongly basic solution. This means the concentration of hydroxide ions ($OH^$) is significantly higher than the concentration of hydronium ions ($H_3O^+$).</p> Signup and view all the answers

<p>The farmer could add a base, such as lime (calcium oxide) or slaked lime (calcium hydroxide), to the soil. These substances react with the excess acid in the soil, neutralizing it and raising the pH to a more suitable level for plant growth.</p> Signup and view all the answers

<p>Water of crystallization refers to the fixed number of water molecules present in one formula unit of a salt. For example, copper sulfate pentahydrate ($CuSO_4 \cdot 5H_2O$) has five water molecules for every one formula unit of copper sulfate.</p> Signup and view all the answers

<p>An indicator is a substance that changes color depending on whether it is in an acidic or a basic solution. By observing the color change of the indicator when added to a solution, one can determine the nature (acidic or basic) of the solution.</p> Signup and view all the answers

<p>A neutralization reaction is a reaction in which an acid and a base react to form a salt and water. General equation: $Acid + Base \rightarrow Salt + Water$. Specific example: $HCl(aq) + NaOH(aq) \rightarrow NaCl(aq) + H_2O(l)$</p> Signup and view all the answers

<p>Strong acids and strong bases are substances that completely ionize in water, meaning they dissociate entirely into ions. Weak acids and weak bases, on the other hand, only partially ionize in water, establishing an equilibrium between the undissociated molecules and their ions.</p> Signup and view all the answers

<p>pH is crucial in many biological and chemical processes. For example, the pH of blood must be maintained within a narrow range (around 7.4) for proper bodily function. Also, enzymes in the digestive system require specific pH levels to function effectively in breaking down food.</p> Signup and view all the answers

<p>When carbon dioxide gas is passed through lime water, it turns milky due to the formation of calcium carbonate: $Ca(OH)_2(aq) + CO_2(g) \rightarrow CaCO_3(s) + H_2O(l)$. If excess carbon dioxide is passed through, the milkiness disappears as calcium bicarbonate is formed: $CaCO_3(s) + H_2O(l) + CO_2(g) \rightarrow Ca(HCO_3)_2(aq)$</p> Signup and view all the answers

<p>The universal indicator shows a range of colors corresponding to different pH values, allowing for an estimation of the strength of an acid or base. Unlike litmus, which only indicates whether a solution is acidic or basic, the universal indicator provides information about the approximate pH value and thus the relative strength.</p> Signup and view all the answers

<p>Turmeric contains curcumin, which is yellow in acidic and neutral solutions but turns reddish-brown in alkaline (basic) solutions. Soap, being basic, causes this color change. Rinsing removes the alkaline soap, restoring a neutral pH and the original yellow color.</p> Signup and view all the answers

<p>The pH is likely above 4.4, as methyl orange turns yellow at this pH and above. A pH meter or universal indicator can confirm the pH range.</p> Signup and view all the answers

<p>Boil red cabbage leaves in water, then strain to obtain the indicator solution. In acidic solutions, it will turn red or pink, and in basic solutions, it will turn green or yellow.</p> Signup and view all the answers

<p>Litmus is derived from lichens, a symbiotic organism. It contains compounds that change color depending on the pH of the solution, turning red in acidic conditions and blue in basic conditions.</p> Signup and view all the answers

<p>Dip both red and blue litmus paper into each solution. The solution that turns red litmus blue is basic. The solution that turns blue litmus red is acidic. The solution that doesn't change either paper is neutral.</p> Signup and view all the answers

<p>Many acids and bases are corrosive and can cause severe burns or tissue damage. Some may be toxic if ingested.</p> Signup and view all the answers

<p>Indicators signal the endpoint of a titration by changing color, indicating neutralization. Without an indicator, it would be impossible to visually determine when the reaction is complete, leading to inaccurate results.</p> Signup and view all the answers

<p>Indicator molecules have conjugated systems that can undergo resonance. Changes in pH cause protonation or deprotonation, altering the electron distribution and thus changing the wavelengths of light absorbed, resulting in a color change.</p> Signup and view all the answers

<p>Strong acids completely ionize in water, producing a high concentration of ions, making them excellent conductors of electricity. Weak acids only partially ionize, resulting in a lower concentration of ions and poorer conductivity.</p> Signup and view all the answers

<p>Hydrangeas contain pigments that react with aluminum ions in the soil. In acidic soils, aluminum is more soluble and available, leading to blue flowers. In alkaline soils, aluminum is less available, resulting in pink flowers.</p> Signup and view all the answers

<p>The small peak separation suggests a quasi-reversible or reversible electron transfer. The potential near the isoelectric point indicates that the surfactant likely forms a tightly packed, self-assembled monolayer on the gold electrode surface, facilitating efficient electron tunneling.</p> Signup and view all the answers

<p>The concentration of $HA^-$ is maximal when the pH equals the average of $pK_{a1}$ and $pK_{a2}$. Therefore, $pH = (2.0 + 7.0)/2 = 4.5$. This occurs because at this pH, the deprotonation of $H_2A$ to $HA^-$ balances with the further deprotonation of $HA^-$ to $A^{2-}$.</p> Signup and view all the answers

<ol> <li>React NaCl with concentrated $H_2SO_4$ to produce HCl gas. 2. Oxidize HCl to chlorine gas ($Cl_2$) via electrolysis. 3. React $Cl_2$ with water to produce hypochlorous acid ($HOCl$). Catalytically oxidize HOCl to chloric acid ($HClO_3$). 4. Treat $HClO_3$ with $H_2SO_4$ to produce $HClO_4$, which is then distilled under reduced pressure to achieve high concentration.</li> </ol> Signup and view all the answers

<p>At pH 7.0, the dominant species are $H_2X^-$ and $HX^{2-}$ as pH is equal to $pK_{a2}$. Using the Henderson-Hasselbalch equation, the concentrations of $H_2X^-$ and $HX^{2-}$ should be equal. $H_3X$ and $X^{3-}$ will be present in very minimal concentrations. The buffer will provide maximum buffering around pH 7, where the $H_2X^-$ and $HX^{2-}$ concentrations are highest.</p> Signup and view all the answers

<p>Perchloric acid is a suitable titrant because it is a stronger acid than acetic acid and can effectively protonate weak bases in this medium. The small autoprotolysis constant of acetic acid results in a sharper endpoint and larger potential break in the titration curve than aqueous titrations, enhancing sensitivity.</p> Signup and view all the answers

<p>The simulation protocol must involve: 1) building a reverse micelle model; 2) positioning the Brønsted acid at the core; 3) equilibrating counterions; 4) performing a series of simulations with varying protonation states; and 5) computing the potential of mean force for each species for accurate $pK_a$ determination. Water structure and interfacial tension must subsequently be analysed.</p> Signup and view all the answers

<p>Use NMR to identify the formation of highly delocalized, weakly coordinating anions characteristic of superacids, and observe large downfield shifts in proton resonances due to extreme protonation. Spectroscopic signatures would include unique vibrational modes in IR and Raman spectra associated with specific superacid-generated ions.</p> Signup and view all the answers

<p>Cyclodextrin encapsulation can selectively stabilize one form of the indicator (acid or base) via hydrophobic interactions, shifting the equilibrium and altering its spectral properties. The magnitude of this shift depends on the binding affinity and encapsulation geometry, thereby causing deviations in pH measurements.</p> Signup and view all the answers

<p>The leveling effect occurs because all acids stronger than $H_3O^+$ in water are effectively converted to $H_3O^+$. One can circumvent this effect by using a non-aqueous solvent with a weaker conjugate acid, which allows for the differentiation of stronger acids by minimizing their dissociation.</p> Signup and view all the answers

<p>The common ion effect reduces the solubility of a sparingly soluble salt by shifting the solubility equilibrium towards precipitation, as the presence of the common ion increases the ion product. Competing equilibria like metal-ligand complexation or pH buffering can counteract this effect by consuming the metal cation or altering the concentration of the anion through protonation/deprotonation reactions.</p> Signup and view all the answers

<p>Acids turn blue litmus paper red.</p> Signup and view all the answers

<p>Baking soda is a base which neutralizes excess stomach acid.</p> Signup and view all the answers

<p>Red cabbage leaves, turmeric, and colored petals of flowers like Hydrangea, Petunia, and Geranium.</p> Signup and view all the answers

<p>The stain turns reddish-brown because soap is basic and turmeric acts as an indicator, changing color in the presence of a base.</p> Signup and view all the answers

<p>Natural indicators are derived from natural sources (e.g., litmus from lichen), while synthetic indicators are man-made (e.g., methyl orange).</p> Signup and view all the answers

<p>Acids and bases have opposite properties, and when they react, they neutralize each other's effects, often forming water and a salt.</p> Signup and view all the answers

<p>It indicates the solution is likely basic or neutral. Methyl orange is red in acidic solutions and yellow in basic solutions.</p> Signup and view all the answers

<p>Boil red cabbage leaves in water, then add the solution to the resulting liquid. If the liquid turns red or pink, the solution is acidic. If it turns green or blue, the solution is basic.</p> Signup and view all the answers

<p>Not definitively. It only indicates that the substance has a pH near 7, but litmus paper has limited sensitivity. The substance could be weakly acidic or basic.</p> Signup and view all the answers

<p>Add a tiny amount of each solution to litmus paper. The one turning red is the acid, the one turning blue is the base. To confirm, add a drop of each to methyl orange; the acid will turn it red. Phenolphthalein will remain colorless with the acid and turn pink with the base.</p> Signup and view all the answers

Substances that taste sour and turn blue litmus red.

Substances that taste bitter and turn red litmus blue.

A method to determine if a solution is acidic or basic using litmus paper.

Substances that change color in the presence of acids or bases.

The reaction where acids and bases cancel each other's effects.

A synthetic indicator that turns red in acid and yellow in base.

Natural indicator that turns yellow in base and reddish-brown in acid.

A synthetic indicator that turns pink in basic solutions.

Substances derived from plants that indicate pH changes.

Paper used to test for acidity; turns red in acid.

The sour flavor characteristic of acids.

The sharp flavor associated with bases.

Acids turn blue litmus red; bases turn red litmus blue.

Turmeric turns yellow in basic solutions and reddish-brown in acidic solutions.

A liquid indicator derived from lichen that changes color with pH.

Chemical substances like methyl orange and phenolphthalein used to test pH.

When an acid reacts with a base to neutralize their properties.

Turns red in acidic solutions and yellow in basic solutions.

Turns colorless in acid and pink in basic solutions.

In neutral solution, litmus remains purple, indicating no acidity or basicity.

Acids are sour, turn blue litmus red, and can neutralize bases.

Bases are bitter, turn red litmus blue, and can neutralize acids.

Turmeric turns yellow in basic solutions and reddish-brown in acidic solutions.

Natural materials like turmeric and cabbage are examples of acid-base indicators.

Synthetic indicators like methyl orange and phenolphthalein identify acid or base presence.

Baking soda (a base) neutralizes acid effects, reducing acidity symptoms.

Litmus is a dye extracted from lichen, used to test pH levels.

Red cabbage leaves can indicate acidity or basicity through color changes.

Litmus remains purple when neither acidic nor basic.

Acids turn blue litmus paper red, indicating acidity.

Bases turn red litmus paper blue, indicating basicity.

Acids and bases neutralize each other when mixed.

Baking soda neutralizes acidity and alleviates symptoms.

Turmeric turns yellow in basic solutions, indicating basicity.

Red cabbage changes color to show pH levels in solutions.

Indicators like litmus help identify acidic or basic solutions.

Litmus is a natural dye used to indicate pH levels by changing color.

The process where acids and bases react to nullify each other's effects.

Turmeric turns yellow in basic solutions and reddish-brown in acidic solutions.

Red cabbage leaves change color to indicate acidity or basicity in solutions.

Baking soda neutralizes acidity, providing relief from acidity symptoms.

Methyl orange turns red in acidic solutions and yellow in basic solutions.

Litmus solution is purple in neutral state and changes with acidity or basicity.