What ions make ammonia solution alkaline?

A. Cl- ions

B. H+ ions

C. Na+ ions

D. OH- ions

Answer Explanation:

A) Cl- ions: Chloride ions (Cl-) are typically found in salts and do not contribute directly to the alkalinity of ammonia solution.

B) H+ ions: Hydrogen ions (H+) typically characterize acidic solutions, not alkaline solutions. Ammonia solution doesn't contain H+ ions.

C) Na+ ions: Sodium ions (Na+) are typically found in salts and do not contribute directly to the alkalinity of ammonia solution.

D) OH- ions (Correct Answer): Ammonia solution becomes alkaline due to the presence of hydroxide ions (OH-). Ammonia (NH3) reacts with water to form ammonium ions (NH4+) and hydroxide ions (OH-), increasing the concentration of OH- ions and making the solution alkaline.

Therefore, the Correct Answer is D.

Q #1: :pH is a measure of how acidic or basic a substance is. The pH scale ranges from:

A. 0–7

B. 7–14

C. 0–14

D. 1–10

Answer Explanation

A. 0–7: This range corresponds to acidic solutions on the pH scale. A pH value below 7 indicates acidity.

B. 7–14: This range corresponds to basic solutions on the pH scale. A pH value above 7 indicates alkalinity.

C. 0–14 (Correct Answer): The pH scale ranges from 0 to 14, covering the entire spectrum of acidity and alkalinity. A pH value of 7 is considered neutral, while values below 7 indicate acidity and values above 7 indicate alkalinity.

D. 1–10: This range does not encompass the full range of the pH scale. The pH scale extends beyond 10 for alkaline solutions and below 1 for highly acidic solutions. Therefore, this choice is incorrect.
Q #2: When copper sulfate is made by reacting copper oxide with sulfuric acid, the acid is heated. Why?

A. To increase the rate of reaction

B. To decrease the rate of reaction

C. To prevent the formation of byproducts

D. To decrease the energy of activation

Answer Explanation

A) To increase the rate of reaction (Correct Answer): Heating the sulfuric acid increases the kinetic energy of the particles, leading to more frequent and energetic collisions between the reactant particles. This, in turn, increases the rate of reaction between copper oxide and sulfuric acid, facilitating the production of copper sulfate.

B) To decrease the rate of reaction: Heating typically increases the rate of reaction by providing more energy for particles to overcome the activation energy barrier. Decreasing the temperature would slow down the reaction, which is not the intended outcome in this scenario.

C) To prevent the formation of byproducts: While heating may influence the selectivity of reactions and the formation of byproducts in some cases, the primary purpose of heating sulfuric acid in this context is to increase the rate of reaction rather than to prevent the formation of byproducts.

D) To decrease the energy of activation: Heating increases the energy of particles, helping them overcome the energy barrier required for the reaction to occur. Therefore, heating sulfuric acid would increase the energy of activation rather than decrease it.
Q #3: 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.

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What ions make ammonia solution alkaline?

More Questions on TEAS 7 Science

Q #1: :pH is a measure of how acidic or basic a substance is. The pH scale ranges from:

Answer Explanation

Q #2: When copper sulfate is made by reacting copper oxide with sulfuric acid, the acid is heated. Why?

Answer Explanation

Q #3: Why is dry hydrogen chloride gas not acidic?

Answer Explanation

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