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Why is dry hydrogen chloride gas not acidic?

A. Because it does not react with water

B. Because it does not contain hydrogen ions (H+)

C. Because it contains hydrogen ions but not chloride ions (Cl-)

D. Because hydrogen is bonded to chlorine in dry HCl and not dissociated

Answer Explanation:

A) Because it does not react with water: While dry hydrogen chloride gas does not react with water, the absence of this reaction does not inherently determine its acidity. Acidity is determined by the presence of hydrogen ions in solution.

B) Because it does not contain hydrogen ions (H+): Dry hydrogen chloride gas does not contain free hydrogen ions, which are characteristic of acidic solutions. However, the absence of hydrogen ions alone does not explain why dry hydrogen chloride gas is not acidic.

C) Because it contains hydrogen ions but not chloride ions (Cl-): Dry hydrogen chloride gas does not contain free chloride ions, but the presence of hydrogen ions is crucial for acidity. However, the absence of chloride ions alone does not fully explain why dry hydrogen chloride gas is not acidic.

D) Because hydrogen is bonded to chlorine in dry HCl and not dissociated (Correct Answer): Dry hydrogen chloride gas does not dissociate into hydrogen ions (H+) and chloride ions (Cl-) because there is no water present to facilitate dissociation. Therefore, it does not exhibit acidic properties in the absence of dissociation.

Therefore, the Correct Answer is D.

More Questions on TEAS 7 Science

  • Q #1: What type of reaction occurs between sulfuric acid and ammonia?

    A. Oxidation

    B. Reduction

    C. Neutralization

    D. Precipitation

    Answer Explanation

    A) Oxidation: Sulfuric acid and ammonia do not participate in an oxidation-reduction reaction, where one substance loses electrons (oxidation) and another gains electrons (reduction).

    B) Reduction: Sulfuric acid and ammonia do not participate in an oxidation-reduction reaction, so reduction is not the correct type of reaction.

    C) Neutralization (Correct Answer): When sulfuric acid reacts with ammonia, a neutralization reaction occurs. The acidic hydrogen ions (H+) from sulfuric acid react with the basic ammonia molecules (NH3) to form ammonium ions (NH4+) and sulfate ions (SO4^2-), resulting in the formation of an ammonium sulfate salt.

    D) Precipitation: A precipitation reaction occurs when two solutions react to form an insoluble solid (precipitate). However, sulfuric acid and ammonia do not form an insoluble product when they react. Therefore, precipitation is not the correct type of reaction for this scenario.

  • Q #2: A solution with a pH of 5.0 _____.

    A. has a hydrogen-ion concentration of 5.0M

    B. is neutral

    C. has a hydroxide-ion concentration of 1 x 10 –9 M

    D. None of the above

    Answer Explanation

    a. is basic: Incorrect. Solutions with pH values less than 7 are acidic, not basic. A pH of 5.0 indicates an acidic solution.

    b. has a hydrogen-ion concentration of 5.0M: Incorrect. The pH value does not directly provide information about the concentration of hydrogen ions. pH is a logarithmic scale that measures the concentration of hydrogen ions in a solution.

    c. is neutral: Incorrect. Solutions with a pH of 7 are considered neutral. A pH of 5.0 indicates an acidic solution.

    d. has a hydroxide-ion concentration of 1 x 10 –9 M: Incorrect. This statement relates to the calculation of hydroxide-ion concentration in a neutral solution using the Kw value (the ion product of water). It does not directly pertain to the pH value of the solution.

  • Q #3: 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.