Acids MCQ Quiz - Objective Question with Answer for Acids - Download Free PDF

The Correct answer is The sting injects methanoic acid.

Key Points

• Bee stings are painful because they inject methanoic acid (also known as formic acid) into the skin.
• This acid causes a burning sensation and can lead to redness, swelling, and inflammation at the site of the sting.
• The injection of methanoic acid triggers the body's immune response, which includes the release of histamines leading to pain and irritation.
• Methanoic acid is a weak acid, but in the concentrated form as injected by bees, it can cause significant discomfort.
• The severity of the reaction can vary based on individual allergies and the number of stings received.

 Additional Information

• The sting releases carbon dioxide gas
  • This is incorrect because a bee sting does not release carbon dioxide gas; instead, it injects a liquid containing methanoic acid.
• The sting injects a mild sugar solution
  • Bee stings do not involve the injection of a sugar solution; they inject methanoic acid which causes pain and inflammation.
• The sting contains a strong base
  • A bee sting does not contain a strong base; it contains methanoic acid, which is an acid, not a base.

The Correct answer is The sting injects methanoic acid.

Key Points

• Bee stings are painful because they inject methanoic acid (also known as formic acid) into the skin.
• This acid causes a burning sensation and can lead to redness, swelling, and inflammation at the site of the sting.
• The injection of methanoic acid triggers the body's immune response, which includes the release of histamines leading to pain and irritation.
• Methanoic acid is a weak acid, but in the concentrated form as injected by bees, it can cause significant discomfort.
• The severity of the reaction can vary based on individual allergies and the number of stings received.

 Additional Information

• The sting releases carbon dioxide gas
  • This is incorrect because a bee sting does not release carbon dioxide gas; instead, it injects a liquid containing methanoic acid.
• The sting injects a mild sugar solution
  • Bee stings do not involve the injection of a sugar solution; they inject methanoic acid which causes pain and inflammation.
• The sting contains a strong base
  • A bee sting does not contain a strong base; it contains methanoic acid, which is an acid, not a base.

The correct answer is The sting injects methanoic acid.

Key Points

• Bee stings cause pain and irritation because they inject methanoic acid (formic acid), which is a toxic substance.
• Methanoic acid triggers a localized inflammatory reaction, leading to redness, swelling, and pain at the sting site.
• The venom also contains proteins that affect skin cells and the immune system, further aggravating the irritation.
• The acidic nature of the venom lowers the pH at the sting site, intensifying the burning sensation.
• Immediate treatment such as neutralizing the acid with a mild base (like baking soda) can help alleviate the discomfort.

Additional Information

• Methanoic Acid (Formic Acid):
  • A simple carboxylic acid with the chemical formula HCOOH.
  • Commonly found in nature, including in ant venom and bee stings.
• Bee Venom:
  • A complex mixture of proteins, peptides, and enzymes.
  • It contains compounds such as melittin, which can cause pain and inflammation.
• Inflammatory Response:
  • The body’s natural reaction to injury or infection, characterized by redness, swelling, and pain.
  • Involves the release of histamines and other chemicals that increase blood flow to the affected area.
• First Aid for Bee Stings:
  • Remove the stinger by scraping it off with a blunt object (e.g., a credit card).
  • Wash the area with soap and water, then apply a cold pack to reduce swelling.
  • Neutralize the acid with a baking soda paste or apply an antihistamine cream for relief.
• Precautionary Measures:
  • Avoid provoking bees or disturbing their hives.
  • Wear protective clothing when in areas with a high bee population.

The correct answer is 1) HCl.

Key Points

• Hydrochloric acid (HCl) is a strong acid commonly found in the stomach, where it aids in digestion.
• HCl is widely used in various industrial processes, including the production of chlorides, fertilizers, and dyes.
• In laboratories, HCl is used as a reagent for titrations and pH control.
• HCl is a colorless and highly corrosive liquid with a pungent smell.

Additional Information

• Acid: A substance that releases hydrogen ions (H+) when dissolved in water, resulting in a pH less than 7.
• Strong Acid: An acid that completely dissociates in water, releasing all its hydrogen ions.
• pH Scale: A scale used to measure the acidity or basicity of a solution, ranging from 0 (highly acidic) to 14 (highly basic), with 7 being neutral.
• Corrosive Substance: A chemical that can cause damage to living tissue or materials through chemical reactions.
• Laboratory Reagent: A substance used in chemical reactions to detect, measure, or produce other substances.

The correct answer is Phosphorous acid.

Key Points

• Phosphorous acid (H₃PO₃) is a dibasic acid.
• It has two acidic hydrogen atoms that can dissociate in an aqueous solution.
• This characteristic allows it to donate two protons, making it a dibasic acid.
• Phosphorous acid is often used in the preparation of phosphite salts, which are important in agriculture and industry.

Additional Information

• Phosphoric Acid (H₃PO₄)
  • Phosphoric acid is a tribasic acid with three hydrogen atoms available for donation.
  • It is widely used in the food industry, especially in cola beverages.
  • In agriculture, it is used as a fertilizer component.
• Boric Acid (H₃BO₃)
  • Boric acid is a weak monobasic acid.
  • It is commonly used as an antiseptic, insecticide, and flame retardant.
• Arsenic Acid (H₃AsO₄)
  • Arsenic acid is a tribasic acid similar to phosphoric acid.
  • It is used in the manufacture of arsenate wood preservatives.
• Acidity
  • Acidity refers to the ability of a substance to donate hydrogen ions (H⁺) in an aqueous solution.
  • Acids are classified based on the number of hydrogen ions they can donate (monobasic, dibasic, tribasic).

The correct answer is The acid present in tomatoes.

Key Points

• Oxalic acid is a chemical compound that occurs naturally in almost every plant to some degree, including fruit, vegetable and grain plants. 
• Tomato contains more than 10 types of acids such as citric acid, malic acid, ascorbic acid, oxalic acid etc. 
• The oxalic acid content of tomatoes is about 50 mg per 100 g serving. 

Additional Information 

• Some natural sources of acid:

The correct answer is 1) HCl.

Key Points

• Hydrochloric acid (HCl) is a strong acid commonly found in the stomach, where it aids in digestion.
• HCl is widely used in various industrial processes, including the production of chlorides, fertilizers, and dyes.
• In laboratories, HCl is used as a reagent for titrations and pH control.
• HCl is a colorless and highly corrosive liquid with a pungent smell.

Additional Information

• Acid: A substance that releases hydrogen ions (H+) when dissolved in water, resulting in a pH less than 7.
• Strong Acid: An acid that completely dissociates in water, releasing all its hydrogen ions.
• pH Scale: A scale used to measure the acidity or basicity of a solution, ranging from 0 (highly acidic) to 14 (highly basic), with 7 being neutral.
• Corrosive Substance: A chemical that can cause damage to living tissue or materials through chemical reactions.
• Laboratory Reagent: A substance used in chemical reactions to detect, measure, or produce other substances.

The Correct answer is The sting injects methanoic acid.

Key Points

• Bee stings are painful because they inject methanoic acid (also known as formic acid) into the skin.
• This acid causes a burning sensation and can lead to redness, swelling, and inflammation at the site of the sting.
• The injection of methanoic acid triggers the body's immune response, which includes the release of histamines leading to pain and irritation.
• Methanoic acid is a weak acid, but in the concentrated form as injected by bees, it can cause significant discomfort.
• The severity of the reaction can vary based on individual allergies and the number of stings received.

 Additional Information

• The sting releases carbon dioxide gas
  • This is incorrect because a bee sting does not release carbon dioxide gas; instead, it injects a liquid containing methanoic acid.
• The sting injects a mild sugar solution
  • Bee stings do not involve the injection of a sugar solution; they inject methanoic acid which causes pain and inflammation.
• The sting contains a strong base
  • A bee sting does not contain a strong base; it contains methanoic acid, which is an acid, not a base.

The correct answer is The sting injects methanoic acid.

Key Points

• Bee stings cause pain and irritation because they inject methanoic acid (formic acid), which is a toxic substance.
• Methanoic acid triggers a localized inflammatory reaction, leading to redness, swelling, and pain at the sting site.
• The venom also contains proteins that affect skin cells and the immune system, further aggravating the irritation.
• The acidic nature of the venom lowers the pH at the sting site, intensifying the burning sensation.
• Immediate treatment such as neutralizing the acid with a mild base (like baking soda) can help alleviate the discomfort.

Additional Information

• Methanoic Acid (Formic Acid):
  • A simple carboxylic acid with the chemical formula HCOOH.
  • Commonly found in nature, including in ant venom and bee stings.
• Bee Venom:
  • A complex mixture of proteins, peptides, and enzymes.
  • It contains compounds such as melittin, which can cause pain and inflammation.
• Inflammatory Response:
  • The body’s natural reaction to injury or infection, characterized by redness, swelling, and pain.
  • Involves the release of histamines and other chemicals that increase blood flow to the affected area.
• First Aid for Bee Stings:
  • Remove the stinger by scraping it off with a blunt object (e.g., a credit card).
  • Wash the area with soap and water, then apply a cold pack to reduce swelling.
  • Neutralize the acid with a baking soda paste or apply an antihistamine cream for relief.
• Precautionary Measures:
  • Avoid provoking bees or disturbing their hives.
  • Wear protective clothing when in areas with a high bee population.

The correct answer is The acid present in tomatoes.

Key Points

• Oxalic acid is a chemical compound that occurs naturally in almost every plant to some degree, including fruit, vegetable and grain plants. 
• Tomato contains more than 10 types of acids such as citric acid, malic acid, ascorbic acid, oxalic acid etc. 
• The oxalic acid content of tomatoes is about 50 mg per 100 g serving. 

Additional Information 

• Some natural sources of acid:

The correct answer is Acetic acid.

Key Points

• Acetic acid is the primary component of vinegar.
• It is commonly used as a souring agent in pickled vegetables and sauces.
• Acetic acid has a distinctive sour taste and pungent smell.
• In addition to its use in culinary applications, acetic acid is also used as a raw material in the production of various chemical compounds.

Additional Information

• Citric acid:
  • Citric acid is a weak organic acid found naturally in citrus fruits like lemons and oranges.
  • It is often used as a preservative and flavoring agent in foods and beverages.
  • Citric acid is also used in cleaning products due to its ability to remove stains and limescale.
• Tartaric acid:
  • Tartaric acid is a naturally occurring acid found in grapes and bananas.
  • It is commonly used in baking powders and as an acidulant in foods and beverages.
  • Tartaric acid is also used in the wine-making process to control acidity.
• Formic acid:
  • Formic acid is a simple carboxylic acid found in the venom of ants and bees.
  • It is used in agriculture for preserving livestock feed and as a miticide in beekeeping.
  • Formic acid is also used in various industrial applications, including leather production and textile processing.

The correct answer is Magnesium hydroxide.

Key Points

• Magnesium hydroxide is commonly used as an antacid to neutralize stomach acid and relieve indigestion and heartburn.
• It is often referred to as "milk of magnesia" due to its milky appearance.
• Magnesium hydroxide works by neutralizing hydrochloric acid in the stomach, thereby increasing the pH level and reducing acidity.
• It is also used as a laxative to relieve constipation by drawing water into the intestines and promoting bowel movements.

Additional Information

• Antacids:
  • Antacids are substances that neutralize stomach acidity and are used to relieve heartburn, indigestion, or an upset stomach.
  • Common active ingredients include magnesium hydroxide, aluminum hydroxide, calcium carbonate, and sodium bicarbonate.
  • Antacids provide quick relief from symptoms but do not heal the underlying cause of acid-related conditions.
• Mechanism of Action:
  • Antacids work by neutralizing the excess hydrochloric acid in the stomach, which increases the pH level and reduces acidity.
  • This action provides relief from pain and discomfort caused by acid reflux and indigestion.
• Other Uses of Magnesium Hydroxide:
  • Besides being an antacid, magnesium hydroxide is also used as a laxative to treat constipation.
  • It works by drawing water into the intestines, which helps to soften stools and stimulate bowel movements.
• Safety and Side Effects:
  • Common side effects of magnesium hydroxide include diarrhea, cramping, and an imbalance in electrolytes if used excessively.
  • Patients with kidney disease should use magnesium hydroxide with caution due to the risk of magnesium accumulation.

The Correct answer is H⁺.

Key Points

• The presence of H⁺ ions in a solution is what makes an acid exhibit its acidic properties.
• When an acid is dissolved in water, it releases hydrogen ions (H⁺), which are responsible for the acidic nature of the solution.
• The strength of an acid is determined by the concentration of H⁺ ions in the solution.
• H⁺ ions are also known as protons, and they can combine with water molecules to form hydronium ions (H₃O⁺).
• The pH scale is used to measure the acidity or alkalinity of a solution, where a lower pH value indicates a higher concentration of H⁺ ions and thus a more acidic solution.

 Additional Information

• OH^-
  • Hydroxide ions (OH^-) are responsible for the basic properties of a solution.
  • Bases release OH^- ions in solution, which can neutralize H⁺ ions.
• Cl^-
  • Chloride ions (Cl^-) are typically found in salts and do not contribute to the acidity of a solution.
  • For example, in hydrochloric acid (HCl), H⁺ is responsible for acidity, while Cl^- is the conjugate base.
• Na⁺
  • Sodium ions (Na⁺) are typically found in salts and do not contribute to the acidity of a solution.
  • In solutions, Na⁺ ions are usually paired with anions and do not affect the pH significantly.

The correct answer is Carboxylic acid.

Key Points

• Soaps are defined as the sodium or potassium salts of fatty acids, which are a subcategory of carboxylic acids.
• Carboxylic acids have the general formula R-COOH, where R is a hydrocarbon chain.
• In the soap-making process called saponification, triglycerides react with sodium hydroxide (NaOH) or potassium hydroxide (KOH) to form glycerol and the sodium or potassium salts of the fatty acids.
• The carboxylate end of the soap molecule is hydrophilic (water-attracting), while the long hydrocarbon chain is hydrophobic (water-repelling), which helps in emulsifying oils and greases in water, allowing them to be washed away.
• Common examples of fatty acids used in soap making include stearic acid, palmitic acid, and oleic acid.

 Additional Information

• Sulphuric acid
  • Sulphuric acid (H₂SO₄) is a strong mineral acid used in various industrial processes such as fertilizer production, petroleum refining, and chemical synthesis.
  • It is not used in soap making due to its strong acidic nature and inability to form salts with fatty acids.
• Nitric acid
  • Nitric acid (HNO₃) is another strong mineral acid used primarily in the production of fertilizers, explosives, and in metal processing.
  • It does not react with fatty acids to form soaps.
• Hydrochloric acid
  • Hydrochloric acid (HCl) is a strong acid used in metal cleaning, food processing, and the production of chlorides.
  • It does not participate in the soap-making process.

The correct answer is Phosphorous acid.

Key Points

• Phosphorous acid (H₃PO₃) is a dibasic acid.
• It has two acidic hydrogen atoms that can dissociate in an aqueous solution.
• This characteristic allows it to donate two protons, making it a dibasic acid.
• Phosphorous acid is often used in the preparation of phosphite salts, which are important in agriculture and industry.

Additional Information

• Phosphoric Acid (H₃PO₄)
  • Phosphoric acid is a tribasic acid with three hydrogen atoms available for donation.
  • It is widely used in the food industry, especially in cola beverages.
  • In agriculture, it is used as a fertilizer component.
• Boric Acid (H₃BO₃)
  • Boric acid is a weak monobasic acid.
  • It is commonly used as an antiseptic, insecticide, and flame retardant.
• Arsenic Acid (H₃AsO₄)
  • Arsenic acid is a tribasic acid similar to phosphoric acid.
  • It is used in the manufacture of arsenate wood preservatives.
• Acidity
  • Acidity refers to the ability of a substance to donate hydrogen ions (H⁺) in an aqueous solution.
  • Acids are classified based on the number of hydrogen ions they can donate (monobasic, dibasic, tribasic).