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What ions make ethanoic acid acidic?

A. H+ ions

B. OH- ions

C. Na+ ions

D. Cl- ions

Answer Explanation:

A) H+ ions (Correct Answer): Ethanoic acid (acetic acid) is acidic because it donates protons (H+) in solution, leading to the formation of hydronium ions (H3O+). This process characterizes acids.

 

B) OH- ions: Hydroxide ions (OH-) typically characterize bases, not acids. Ethanoic acid doesn't contain hydroxide ions.

 

C) Na+ ions: Sodium ions (Na+) are not responsible for the acidity of ethanoic acid. Na+ ions are typically found in salts and do not contribute to acidity.

 

D) Cl- ions: Chloride ions (Cl-) are not responsible for the acidity of ethanoic acid. Cl- ions are typically found in salts and do not contribute to acidity.

Therefore, the Correct Answer is A.

More Questions on TEAS 7 Science

  • Q #1: Why is KOH a strong alkali?

    A. Because it reacts vigorously with acids

    B. Because it forms a basic solution when dissolved in water

    C. Because in solution it fully dissociates into K+ and OH-

    D. Because it forms insoluble precipitates with metal cations

    Answer Explanation

    A) Because it reacts vigorously with acids: While KOH does react with acids to form salts and water, the strength of an alkali is not solely determined by its reactivity with acids.

    B) Because it forms a basic solution when dissolved in water: This statement is true, but it does not fully explain why KOH is considered a strong alkali. Many compounds can form basic solutions when dissolved in water.

    C) Because in solution it fully dissociates into K+ and OH- (Correct Answer): KOH is considered a strong alkali because it fully dissociates in aqueous solution into potassium ions (K+) and hydroxide ions (OH-). This dissociation leads to a high concentration of hydroxide ions in solution, making it strongly alkaline.

    D) Because it forms insoluble precipitates with metal cations: This statement describes the formation of insoluble hydroxide precipitates when alkali solutions are added to solutions of metal salts. However, it does not fully explain why KOH itself is considered a strong alkali.

  • Q #2: Why do farmers use ammonium salts on their fields?

    A. To prevent soil erosion

    B. To increase soil acidity

    C. To help plants grow (as fertilizers)

    D. To reduce soil salinity

    Answer Explanation

    A) To prevent soil erosion: While certain soil management practices may involve measures to prevent erosion, the use of ammonium salts specifically does not directly relate to preventing soil erosion.

    B) To increase soil acidity: Ammonium salts, such as ammonium sulfate, can actually decrease soil pH, making the soil more acidic. However, this is not typically the primary reason farmers use these salts.

    C) To help plants grow (as fertilizers) (Correct Answer): Ammonium salts are commonly used as fertilizers because they provide essential nitrogen to plants in a form that they can readily absorb. Nitrogen is a crucial nutrient for plant growth, and ammonium salts serve as a source of nitrogen for crops.

    D) To reduce soil salinity: Ammonium salts are not typically used to reduce soil salinity. Salinity issues in soil are typically addressed through other methods such as leaching or soil amendments, rather than the addition of ammonium salts.

  • Q #3: What is the formula of ammonium sulfate?

    A. NH4SO4

    B. (NH4)2SO4

    C. (NH4)SO4

    D. (NH3)2SO4

    Answer Explanation

    A) NH4SO4: This formula suggests a compound where one ammonium ion is combined with one sulfate ion, which is not the correct composition of ammonium sulfate.

    B) (NH4)2SO4 (Correct Answer): This formula correctly represents ammonium sulfate, indicating that it consists of two ammonium ions (NH4+) and one sulfate ion (SO4^2-).

    C) (NH4)SO4: This formula suggests a compound with one ammonium ion combined with one sulfate ion, which is not the correct composition of ammonium sulfate.

    D) (NH3)2SO4: This formula suggests a compound where two ammonia molecules (NH3) are combined with one sulfate ion, which is incorrect. Ammonium sulfate contains ammonium ions (NH4+), not ammonia molecules (NH3).