Question

Which of the following statements is(are) true? For the false statements, correct them. a. A concentrated solution in water will always contain a strong or weak electrolyte. b. A strong electrolyte will break up into ions when dissolved in water. c. An acid is a strong electrolyte. d. All ionic compounds are strong electrolytes in water.

Short answer

a. True b. True c. False; corrected statement: "An acid can be either a strong or weak electrolyte." d. False; corrected statement: "Most ionic compounds are strong electrolytes in water, but some could be weak electrolytes."

Step-by-step solution

a. Statement Analysis

Statement a says: "A concentrated solution in water will always contain a strong or weak electrolyte." This statement is true as a concentrated solution in water implies the presence of a solute that exhibits ionic properties and will either be a strong or weak electrolyte.

b. Statement Analysis

Statement b says: "A strong electrolyte will break up into ions when dissolved in water." This statement is true. A strong electrolyte dissolves entirely in water and breaks up into its constituent ions. It means that strong electrolytes have a high degree of ionization, almost close to 100% in water. Examples include strong acids such as HCl, strong bases such as NaOH, and ionic salts such as NaCl.

c. Statement Analysis

Statement c says: "An acid is a strong electrolyte." This statement is false. The correct statement should be: "An acid can be either a strong or weak electrolyte." Acids are classified as strong or weak depending on their ability to ionize; strong acids such as HCl and H2SO4 have a high degree of ionization, whereas weak acids such as CH3COOH and HF have low degrees of ionization.

d. Statement Analysis

Statement d says: "All ionic compounds are strong electrolytes in water." This statement is false. The corrected statement should be: "Most ionic compounds are strong electrolytes in water, but some could be weak electrolytes." Ionic compounds generally dissolve in water to form ions, making them strong electrolytes most of the time. However, some ionic compounds don't dissociate completely in water making them weak electrolytes. Examples of such compounds include sparingly soluble salts like lead chloride (PbCl2) and silver chloride (AgCl).

Key concepts

Strong Electrolytes

Strong electrolytes are substances that completely dissociate into ions when dissolved in water. This means they are almost fully ionized, which leads to high electrical conductivity in aqueous solutions. For example, when table salt (NaCl) is added to water, it breaks down into sodium ions (Na\(^+\)) and chloride ions (Cl\(^-\)) entirely.

Strong electrolytes include:

• Strong acids like hydrochloric acid (HCl).
• Strong bases such as sodium hydroxide (NaOH).
• Most salts, like potassium nitrate (KNO\(_3\)).

These substances, because of their high degree of ionization, are often used in applications where maximum conductivity is required, such as in batteries and electrolysis processes.

Acid Ionization

Acid ionization refers to the process where an acid dissociates in water to release hydrogen ions (H\(^+\)). The degree of ionization determines if an acid is strong or weak.

Strong acids, like sulfuric acid (H\(_2\)SO\(_4\)) and nitric acid (HNO\(_3\)), ionize completely in water, producing a high concentration of hydrogen ions. This makes them strong electrolytes.
Weak acids, on the other hand, only partially ionize in water. An example is acetic acid (CH\(_3\)COOH). It does not release all of its hydrogen ions, which results in a less conductive solution. The balance between ionized and non-ionized molecules is crucial for understanding reactions and predicting the behavior of acids in different conditions.

Ionic Compounds Solubility

Ionic compounds are formed by the electrostatic attraction between positively and negatively charged ions. Their solubility in water varies, which directly affects their ability to act as electrolytes.

Most ionic compounds dissociate into ions when dissolved in water, becoming strong electrolytes. Examples include common salts like sodium chloride (NaCl) and potassium carbonate (K\(_2\)CO\(_3\)).
However, some ionic compounds do not dissolve well due to their strong ionic bonds, making them weak or non-electrolytes. For instance, compounds like silver chloride (AgCl) and calcium sulfate (CaSO\(_4\)) have limited solubility in water.
The solubility of ionic compounds is influenced by factors such as temperature, the charge and size of the ions involved, and the presence of other ions in the solution.