Acids, Bases, and Salts Quiz

Sour

Red

Bitter

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

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

<p>Reddish-brown</p> Signup and view all the answers

<p>Methyl orange or phenolphthalein</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, Petunia, or Geranium</p> Signup and view all the answers

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

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

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

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

<p>Methyl orange OR Phenolphthalein</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>It turns reddish-brown</p> Signup and view all the answers

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

<p>Tasting substances can be dangerous because many acids and bases are corrosive and can cause burns or poisoning. Alternative methods involve using indicators like litmus paper, turmeric, or synthetic indicators such as methyl orange or phenolphthalein.</p> Signup and view all the answers

<p>The solution is acidic. It likely contains an excess of hydrogen ions ($\text{H}^+$).</p> Signup and view all the answers

<p>A strong base can cause chemical burns. The immediate step is to flush the affected area with copious amounts of water to dilute and remove the base, and then seek medical attention.</p> Signup and view all the answers

<p>Indicators change color because they are pH-sensitive dyes. In acids or bases, they undergo structural changes that alter their light absorption properties, resulting in a visible color change that signals the presence of an acid or a base.</p> Signup and view all the answers

<p>Curry stain turns reddish-brown with soap because soap is basic, and turmeric (a component of curry) is a natural indicator that changes color in basic conditions. Washing with water removes the soap, and the stain returns to its original yellow color.</p> Signup and view all the answers

<p>Baking soda is a base, and it neutralizes the excess hydrochloric acid ($\text{HCl}$) in the stomach, reducing the acidity through a neutralization reaction.</p> Signup and view all the answers

<p>Synthetic indicators are artificially synthesized chemical compounds, whereas natural indicators are derived from natural sources like plants. Synthetic indicators often provide sharper color changes and can be used in a wider pH range compared to some natural indicators.</p> Signup and view all the answers

<p>Lemon juice turns blue litmus paper red, indicating it is acidic. Using lemon juice on a base burn is not advisable because it would exacerbate the burn by reacting with the base, generating heat and potentially causing more tissue damage.</p> Signup and view all the answers

<p>The red litmus paper will turn blue. The solution exhibits basic or alkaline properties.</p> Signup and view all the answers

<p>Water acts as a solvent, enabling acids to dissociate and release hydrogen ions ($\text{H}^+$) and bases to dissociate and release hydroxide ions ($\text{OH}^-$). This dissociation is essential for acids and bases to exhibit their characteristic properties, such as changing the color of indicators and neutralizing each other.</p> Signup and view all the answers

<p>Adding water to a concentrated acid can generate a large amount of heat, potentially causing the solution to boil and splash, which could lead to burns. Adding acid to water allows the heat to dissipate more safely.</p> Signup and view all the answers

<p>The solution is basic. A pH of 9 indicates that the concentration of hydroxide ions is greater than the concentration of hydronium ions.</p> Signup and view all the answers

<p>A strong acid completely ionizes in water (e.g., hydrochloric acid, HCl), while a weak acid only partially ionizes (e.g., acetic acid, $CH_3COOH$).</p> Signup and view all the answers

<p>$H_2SO_4 + 2NaOH \rightarrow Na_2SO_4 + 2H_2O$. The salt produced is sodium sulfate ($Na_2SO_4$), and water ($H_2O$) is also produced.</p> Signup and view all the answers

<p>Amphoteric substances can act as both acids and bases. Water ($H_2O$) is an example: in an acidic solution, $H_2O + H^+ \rightleftharpoons H_3O^+$, and in a basic solution, $H_2O \rightleftharpoons H^+ + OH^-$.</p> Signup and view all the answers

<p>A buffer solution contains a weak acid and its conjugate base (or a weak base and its conjugate acid). The weak acid neutralizes added base, and the conjugate base neutralizes added acid, minimizing pH changes.</p> Signup and view all the answers

<p>The common ion effect is the decrease in solubility of a sparingly soluble salt when a soluble salt containing a common ion is added to the solution. The presence of the common ion shifts the equilibrium toward the undissolved salt.</p> Signup and view all the answers

<p>Indicators are weak acids or bases that change color depending on the pH of the solution. The color change occurs over a specific pH range, determined by the indicator's $pK_a$ value, near the equivalence point of the titration.</p> Signup and view all the answers

<p>Distilled or deionized water is free from ions and impurities that could affect the pH or react with the acids or bases being studied. Impurities in tap water can introduce unwanted ions, altering the reaction or interfering with measurements.</p> Signup and view all the answers

<p>Acid rain, formed by sulfur dioxide and nitrogen oxides reacting with atmospheric moisture, acidifies lakes and soil, harming aquatic life and damaging vegetation and buildings.</p> Signup and view all the answers

<p>Use a concentration cell with hydrogen electrode. Measure the potential. Use Nernst equation to calulate the concentration of H+ ions and then find Ka.</p> Signup and view all the answers

<p>$Al^{3+}$ ion undergoes hydrolysis, releasing $H^+$ ions and leading to acidity, while $Na^+$ and $Cl^-$ do not significantly hydrolyze, maintaining neutrality.</p> Signup and view all the answers

<p>$\beta = 2.303 ([H_3O^+] + [OH^-] + [HA][A^-]/([HA] + [A^-]))$. This expression demonstrates the dependence of buffer capacity on both the total buffer concentration and the concentrations of hydronium and hydroxide ions.</p> Signup and view all the answers

<p>A scenario where the addition of a strong acid to a solution containing a weak base increases the pH involves the presence of a highly insoluble hydroxide salt (e.g., $Mg(OH)_2$). The strong acid protonates the hydroxide ions, decreasing the hydroxide ion concentration initially, but the dissolution of $Mg(OH)_2$ is increased to compensate, leading to a higher pH if the solubility is sufficiently sensitive to pH changes and the amount of strong acid is small.</p> Signup and view all the answers

<p>Indicators are weak acids or bases. The colour change is a result of equilibrium shifting between their protonated and deprotonated forms. The human eye's ability to distinguish between colors is also gradual due to the continuous spectrum of light.</p> Signup and view all the answers

<p>Use a phosphate buffer system. It has buffering capacity near physiological pH, and is biocompatible. Choose a concentration to ensure the the acid producion rate does not exceed the buffering capacity.</p> Signup and view all the answers

<p>Superacidity refers to acidity exceeding that of 100% sulfuric acid. One mechanism is the protonation of an alkane to form a pentacoordinate carbonium ion. Another is hydrogen abstraction to form a carbenium ion. Example for the first one is $CH_4 + H^+ \rightarrow CH_5^+$.</p> Signup and view all the answers

<p>Successive $pK_a$ values determine the distinctness of the titration curve's inflections. If the values are too close together, complete separation of the titration steps become impossible. Indicators are selected based on their transition range coinciding with each equivalence point.</p> Signup and view all the answers

<p>Employ single-molecule fluorescence microscopy with a pH-sensitive fluorophore. The fluorescence intensity correlates with pH, allowing for the quantification of extremely low hydroxide ion concentrations.</p> Signup and view all the answers

<p>The pH of a solution is not a complete descriptor: pH doesn't show the concentration or types of acids or bases present. Equivalently acidic solutions can have very different buffering capacities. We can use titration curves, or measurements of buffer capacity.</p> Signup and view all the answers

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

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

<p>Soap is basic in nature.</p> Signup and view all the answers

<p>Methyl orange and phenolphthalein.</p> Signup and view all the answers

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

<p>It turns red or pink.</p> Signup and view all the answers

<p>Neutralization.</p> Signup and view all the answers

<p>Many acids and bases can be corrosive or toxic.</p> Signup and view all the answers

<p>The solution is likely basic; test with phenolphthalein; if it turns pink, basic nature is confirmed.</p> Signup and view all the answers

<p>Green indicates neutrality; dilution reduces the concentration of any initially present $H_3O^+$ or $OH^-$ ions, shifting the $H^+/OH^-$ balance towards $OH^-$ due to water's autoionization ($2H_2O ightleftharpoons H_3O^+ + OH^-$) leading to a higher pH and blue color.</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 substance is acidic or basic using litmus paper.

Substances used to show the presence of acids or bases through color change.

The reaction between an acid and a base to cancel each other's effects.

Indicators obtained from plants that indicate acidity or basicity.

Man-made substances that indicate the presence of acids or bases.

A purple dye from lichen, used as an acid-base indicator.

Turmeric turns reddish-brown with a base and yellow when washed.

The chemical processes that occur when acids and bases interact.

Acids are known for their sour taste, commonly found in foods like lemons.

Bases are characterized by a bitter taste, found in substances like baking soda.

A paper used to test acidity or basicity by changing color: red for acid, blue for base.

A solution that is neither acidic nor basic, appears purple with litmus.

A synthetic indicator that turns pink in basic solutions and remains colorless in acidic ones.

A synthetic indicator that is red in acidic solutions and yellow in neutral to basic solutions.

The process where an acid and a base react to cancel each other's properties, forming water and salt.

When turmeric reacts with a base, it turns reddish-brown, returning to yellow when washed.

Substances from plants that show acidity or basicity through color changes.

Litmus solution that indicates neutrality, turning red in acid and blue in base.

Interactions between acids and bases that often result in neutralization.

A basic solution often used to treat excess acidity in the stomach.

Turmeric stain turns reddish-brown with a base and yellow when neutralized.

A natural indicator that changes color with pH level.

Red for acid, blue for base; used to test acidity or basicity.

Turns pink in basic solutions and colorless in acidic solutions.

Natural and synthetic substances used in everyday situations to identify acids and bases.

Acids taste sour and turn blue litmus red.

Bases taste bitter and turn red litmus blue.

Natural substances like turmeric and red cabbage indicating pH.

Turmeric turns reddish-brown with a base and yellow when neutralized.

Litmus indicates acidity or basicity through color change.

When an acid and a base react to cancel each other's effects.

Turns red in acidic solutions and yellow in neutral to basic solutions.

Remains colorless in acidic solutions and turns pink in basic solutions.

Red cabbage can indicate pH changes with color shifts.

The chemical processes that occur when acids and bases react with one another.

Litmus solution is purple when neutral, changes to red in acids, and blue in bases.

Substances that show the presence of acid or base through color changes.

Litmus is derived from lichen, a plant from the division Thallophyta.

A basic solution often recommended to neutralize excess stomach acidity.

Litmus paper turns red in acidic solutions and blue in basic solutions.

Man-made substances that indicate the presence of acids or bases through color change.

Turmeric changes to reddish-brown with a base and yellow when neutralized.

Litmus solution is made from a purple dye extracted from lichen.

Acids and bases change the colors of indicators to signal their presence.

Litmus paper tests acidity or basicity by changing color based on the solution's pH.

Baking soda solution neutralizes stomach acidity and relieves discomfort.