Problem 37 - Chemistry: An Atoms-Focused Approach

Question

What are present in solutions of electrolytes that are not present in solutions of nonelectrolytes?

Step-by-Step Solution

Answer

Question: Compare the contents present in the solutions of electrolytes and nonelectrolytes. Answer: The main difference between the contents of electrolyte and nonelectrolyte solutions is the presence of ions (cations and anions) in electrolyte solutions and the absence of ions in nonelectrolyte solutions. This presence of ions allows electrolyte solutions to conduct electricity, while the lack of ions in nonelectrolyte solutions prevents them from conducting electricity.

Step 1: Understanding Electrolytes and Nonelectrolytes Solutions

Electrolytes are substances that, when dissolved in water, dissociate into ions (cations and anions) and, as a result, the solution can conduct electricity. These ions are charged particles that are free to move in the solution, allowing the flow of an electric current. Nonelectrolytes, on the other hand, are substances that do not dissociate into ions when dissolved in water. Thus, their solution does not conduct electricity because there are no charged particles to facilitate the movement of an electric current.

Step 2: Content in Electrolyte Solutions

In electrolyte solutions, there are ions (cations and anions) present that facilitate the flow of an electric current. These ions can either be positively charged (cations) or negatively charged (anions). For example, when sodium chloride (NaCl) - an electrolyte - dissolves in water, it dissociates into sodium ions (Na^+) and chloride ions (Cl^-), forming an electrolyte solution.

Step 3: Content in Nonelectrolyte Solutions

In nonelectrolyte solutions, there are no ions present. Instead, the solute dissolves as intact molecules, which do not possess any charge. As a result, these solutions do not conduct electricity. For instance, when sucrose (C12H22O11) - a nonelectrolyte - dissolves in water, it remains as intact molecules and does not dissociate into ions.

Step 4: Comparing the Contents of Electrolyte and Nonelectrolyte Solutions

In summary, the key difference between the contents of electrolyte and nonelectrolyte solutions is the presence of ions (cations and anions) in the electrolyte solutions that are not present in nonelectrolyte solutions. The presence of these ions in electrolyte solutions allows them to conduct electricity, while the absence of ions in nonelectrolyte solutions prevents them from conducting electricity.

Key Concepts

Ions

In the world of chemistry, ions are crucial participants in various chemical reactions and processes, especially in solutions. An ion is an atom or molecule that has an unequal number of protons and electrons, giving it a net positive or negative electric charge. Ions can be either cations or anions.

• Cations: These are positively charged ions. This means they have more protons than electrons. For example, sodium ions \(\text{Na}^+\), formed when sodium loses an electron.
• Anions: These have a negative charge, indicating they have more electrons than protons. Chloride ions \(\text{Cl}^-\) are a typical example, formed when chlorine gains an electron.

In solutions, ions are the charged particles that move freely, allowing the solution to conduct electricity. They are present in electrolyte solutions but absent in nonelectrolyte solutions. Without ions, there would be no free charges to carry the electricity, and hence, the solution would not conduct electrical current.

Nonelectrolytes

Nonelectrolytes are substances that, when dissolved in water, do not dissociate into ions. This fundamental property underpins their inability to conduct electricity in solution. Instead of breaking apart into charged particles, nonelectrolytes dissolve as whole molecules, keeping their structural integrity intact.

• For example, when you dissolve sugar like sucrose in water, each sucrose molecule stays complete rather than splitting into ions.
• This intact molecular form means there are no charged particles to support the movement of electric current through the solution.

While both nonelectrolytes and electrolytes dissolve in water, it is the crucial presence or absence of ions that differentiates them. Nonelectrolyte solutions lack the charged particles needed to facilitate electric conductivity, highlighting the unique behavior of these substances in liquid form.

Electric Conductivity

Electric conductivity in solutions refers to the ability to conduct an electric current, and it is heavily dependent on the presence of charge carriers, like ions. When dealing with solutions, one key aspect is whether the dissolved substance can produce ions in water. In electrolyte solutions:

• Ions are abundant, and their freedom to move through the solution means electricity can easily flow. This is why saltwater, which contains dissociated ions from dissolved salts, is a good conductor of electricity.
• The movement of cations and anions in opposite directions under the influence of an electric field is what actually comprises the electric current in the solution.

Conversely, nonelectrolyte solutions cannot conduct electricity because they do not form ions. Without ions, there are no charge carriers to sustain an electric current, rendering these solutions as insulators in terms of electrical conductivity. Understanding this explains why some solutions can conduct electricity effectively, whereas others cannot.