What is an appropriate pH value for hydrochloric acid?

A. pH 2-4

B. pH 1-3

C. pH 0-2

D. pH 3-5

Answer Explanation:

Rationale for each choice:

A) pH 2-4: While hydrochloric acid is indeed highly acidic, a pH range of 2-4 would suggest a slightly less concentrated solution. However, this range might still be appropriate for dilute or partially neutralized hydrochloric acid.

A) pH 1-3 (Correct Answer): Hydrochloric acid typically has a very low pH due to its strong acidic nature. A pH range of 1-3 is commonly observed for concentrated hydrochloric acid solutions.

C) pH 0-2: This range suggests an even stronger acidity, which could be true for very concentrated hydrochloric acid solutions, although they might not commonly occur in typical laboratory or industrial settings.

D) pH 3-5: This pH range would indicate a significantly less acidic solution compared to hydrochloric acid. Such a pH range might be more appropriate for weak acids or diluted hydrochloric acid solutions rather than the concentrated form.

Therefore, the Correct Answer is B.

Q #1: Which one of the following must be added to dilute hydrochloric acid to produce hydrogen?

A. Iron

B. Iron sulfide

C. Copper chloride

D. Sulfur

Answer Explanation

A. Iron (Correct Answer): Iron can react with hydrochloric acid to produce hydrogen gas according to the following reaction:

2HCl + Fe => FeCl2 + H2

So, adding iron to dilute hydrochloric acid would produce hydrogen gas.

B. Iron sulfide: Iron sulfide may react with hydrochloric acid, but it does not directly produce hydrogen gas. The reaction would likely produce hydrogen sulfide gas instead.

C. Copper chloride: Copper chloride does not react with hydrochloric acid to produce hydrogen gas. The reaction between copper chloride and hydrochloric acid would likely produce copper chloride and hydrogen chloride gas.

D. Sulfur: Sulfur does not react with hydrochloric acid to produce hydrogen gas. The reaction between sulfur and hydrochloric acid would likely produce hydrogen sulfide gas.
Q #2: What is produced when an acid reacts with ammonia?

A. Water

B. Ammonia and Water

C. Ammonium salt

D. Hydrogen gas

Answer Explanation

A) Water: Water is not typically produced when an acid reacts with ammonia. Water may be present in the reaction mixture, but it is not a direct product of the reaction between the acid and ammonia.

B) Ammonium chloride: Water and ammonia are not typically produced when an acid reacts with ammonia.

C) Ammonium salt (Correct Answer): When an acid reacts with ammonia, an ammonium salt is typically formed. The specific ammonium salt produced depends on the acid used in the reaction.

D) Hydrogen gas: Hydrogen gas is not typically produced when an acid reacts with ammonia. The reaction between an acid and ammonia does not involve the liberation of hydrogen gas.
Q #3: 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.

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What is an appropriate pH value for hydrochloric acid?

More Questions on TEAS 7 Science

Q #1: Which one of the following must be added to dilute hydrochloric acid to produce hydrogen?

Answer Explanation

Q #2: What is produced when an acid reacts with ammonia?

Answer Explanation

Q #3: What type of reaction occurs between sulfuric acid and ammonia?

Answer Explanation

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