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.

Therefore, the Correct Answer is A.

Q #1: Strong bases are:

A. Strong electrolytes

B. Weak electrolytes

C. Nonelectrolytes

D. Also strong acids

Answer Explanation

a. Strong electrolytes (Correct Answer): Strong bases completely dissociate into ions in solution, making them strong electrolytes. They conduct electricity well due to the presence of a high concentration of ions.

b. Weak electrolytes: Strong bases, unlike weak bases, completely dissociate in solution, resulting in a high concentration of ions. Therefore, they are considered strong electrolytes, not weak electrolytes.

c. Nonelectrolytes: Nonelectrolytes do not ionize in solution and do not conduct electricity. Strong bases, however, ionize completely in solution, making them strong electrolytes.

d. Also strong acids: Strong bases and strong acids are two distinct types of compounds. Strong bases ionize completely in solution to produce hydroxide ions, while strong acids ionize completely to produce hydrogen ions (H+). They are not the same.
Q #2: 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.
Q #3: 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.

Free Access on TEAS 7 Exams and Study Notes

Access to all TEAS 7 Exams
Performance Tracking and Analysis
Well Documented and Explained Questions and Answers
2000+ Questions and Correct Answers: Answers Well Explained
Libary of Detailed StudyNotes
Topical Questions and Answers on Examinable topics

Join Now

Which one of the following must be added to dilute hydrochloric acid to produce hydrogen?

More Questions on TEAS 7 Science

Q #1: Strong bases are:

Answer Explanation

Q #2: What ions make ammonia solution alkaline?

Answer Explanation

Q #3: A solution with a pH of 5.0 _____.

Answer Explanation

Free Access on TEAS 7 Exams and Study Notes

TEAS 7 Exams (Q&A)

TEAS 7 Study Notes

TEAS 7 Topical Tests

TEAS 7 Study Guides

Quick Links

Refer a Friend