Question

Match the following physical and chemical properties with octane, \(\mathrm{C}_{8} \mathrm{H}_{18}\), found in gasoline, or magnesium sulfate, \(\mathrm{MgSO}_{4}\), also called Epsom salts: a. contains only covalent bonds b. melts at \(1124^{\circ} \mathrm{C}\) c. is insoluble in water d. is a liquid at room temperature e. is a strong electrolyte

Short answer

a) Octane, b) Magnesium sulfate, c) Octane, d) Octane, e) Magnesium sulfate

Step-by-step solution

- Identify Octane's Properties

Octane \((C_{8}H_{18})\) is a hydrocarbon, consisting entirely of covalent bonds, primarily single bonds. It is known to be a liquid at room temperature due to its relatively low boiling point. Additionally, because octane is nonpolar, it is insoluble in water.

- Identify Magnesium Sulfate's Properties

Magnesium sulfate \(MgSO_{4}\) is an ionic compound. It melts at a very high temperature \(1124^\circ C\). Unlike octane, magnesium sulfate is soluble in water and acts as a strong electrolyte when dissolved, meaning it dissociates completely into ions in a solution.

- Match the Properties

a. Contains only covalent bonds -> Octane \((C_{8}H_{18})\) \ b. Melts at \(1124^\circ C\) -> Magnesium sulfate \((MgSO_{4})\) \ c. Is insoluble in water -> Octane \((C_{8}H_{18})\) \ d. Is a liquid at room temperature -> Octane \((C_{8}H_{18})\) \ e. Is a strong electrolyte -> Magnesium sulfate \((MgSO_{4})\)

Key concepts

octane

Octane is a hydrocarbon with the chemical formula \(\text{C}_8 \text{H}_{18}\). It's a major component of gasoline. One important property of octane is that it contains only covalent bonds, specifically single bonds between carbon and hydrogen atoms. At room temperature, octane is a liquid, which makes it ideal for use in internal combustion engines. Due to its nonpolar nature, octane is insoluble in water. This means it doesn't mix with water, much like oil.

magnesium sulfate

Magnesium sulfate, also known as Epsom salts, has the chemical formula \(\text{MgSO}_4\). It is an ionic compound made up of magnesium cations \(Mg^{2+}\) and sulfate anions \(SO_4^{2-}\). Magnesium sulfate has a very high melting point (\text{1124}^\text{C}), indicating strong ionic bonds within the compound. When dissolved in water, magnesium sulfate dissociates completely into its ions, making it a strong electrolyte. This means it can conduct electricity well in solution.

covalent bonds

Covalent bonds form when atoms share pairs of electrons. These bonds are typically found in organic compounds like octane \(C_8 H_{18}\). In octane, each carbon atom shares electrons with hydrogen atoms, creating stable single bonds. Covalent compounds usually have lower melting and boiling points compared to ionic compounds. They also tend to be nonpolar and insoluble in water, unless they have polar groups attached to them.

ionic compounds

Ionic compounds are formed when atoms transfer electrons from one to another, creating ions. These ions are held together by strong electrostatic forces. A typical example is magnesium sulfate \(MgSO_4\), comprising \(Mg^{2+}\) and \(SO_4^{2-}\) ions. Ionic compounds like magnesium sulfate typically have high melting points and are soluble in water. They dissociate completely in solution, making them good electrolytes and helping them conduct electricity.

strong electrolytes

Strong electrolytes are substances that completely dissociate into ions when dissolved in water. Magnesium sulfate \(MgSO_4\) is a prime example. When it dissolves, it splits into \(Mg^{2+}\) and \(SO_4^{2-}\) ions. This full dissociation allows the solution to conduct electricity efficiently. Strong electrolytes are essential in many biological and chemical processes, including nerve function and battery operation.