Question

Which of the following solvents might be used to dissolve an oil stain? a. water b. CCl4 c. diethyl ether d. benzene e. NaCl solution

Short answer

CCl4, diethyl ether, or benzene can be used to dissolve an oil stain.

Step-by-step solution

Identify the nature of the stain

Determine the type of substance the oil stain is. Oil is a nonpolar substance.

Understand solubility principles

Recall the principle 'like dissolves like,' which means that polar solvents dissolve polar substances and nonpolar solvents dissolve nonpolar substances.

Classify each solvent

Identify whether each given solvent is polar or nonpolar: - Water is polar. - CCl4 (carbon tetrachloride) is nonpolar. - Diethyl ether is slightly polar but behaves more like a nonpolar solvent. - Benzene is nonpolar. - NaCl solution is polar.

Match solvents with similar properties

Since oil is nonpolar, choose the solvents that are nonpolar or similar to nonpolar characteristics. This implies that CCl4, diethyl ether, and benzene might be used.

Select the best solvent

Given the options, CCl4, diethyl ether and benzene can dissolve the oil stain effectively. Any of these three will work, but typically, CCl4 and benzene are stronger nonpolar solvents for dissolving oils.

Key concepts

polarity

Polarity is a key concept in chemistry that helps us understand how substances interact. Molecules like water have regions with slight positive and negative charges, making them polar.
Polar molecules have an uneven distribution of electrons, causing a dipole moment. This helps them interact with other polar substances.
Conversely, nonpolar molecules have an even electron distribution, which means no partial charges.
Understanding polarity is crucial for predicting solubility. Polar substances will dissolve well in polar solvents, while nonpolar substances dissolve best in nonpolar solvents.

nonpolar solvents

Nonpolar solvents play a significant role in dissolving nonpolar substances like oils. These solvents have molecules with no significant charge difference across them.
Common nonpolar solvents include:

• Carbon tetrachloride (CCl4)
• Benzene
• Hexane

Because they lack poles or charged regions, nonpolar solvents are good at dissolving other nonpolar compounds. For example, oil stains are best treated with nonpolar solvents, as they share similar molecular properties. This 'like dissolves like' principle will be further explained next.

like dissolves like

The principle 'like dissolves like' is a simple yet powerful rule. It states that substances with similar polarity will dissolve in each other.
This can be broken down into:

• Polar solvents, like water, dissolve polar substances, like sugar.
• Nonpolar solvents, like benzene, dissolve nonpolar substances, like oil.

This rule helps predict which solvents will dissolve which solutes. It simplifies the process of selecting the correct solvent for a task, like removing a stain or creating solutions in experiments. Understanding this concept is foundational for solving many chemistry problems.