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Explain why chlorine (Cl₂) is a gas at room temperature, but sodium chloride (NaCl) is a solid at room temperature - AQA - GCSE Chemistry - Question 2 - 2014 - Paper 1
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Explain why chlorine (Cl₂) is a gas at room temperature, but sodium chloride (NaCl) is a solid at room temperature. Chlorine Cl — Cl Sodium chloride Chloride ion... show full transcript
Worked Solution & Example Answer:Explain why chlorine (Cl₂) is a gas at room temperature, but sodium chloride (NaCl) is a solid at room temperature - AQA - GCSE Chemistry - Question 2 - 2014 - Paper 1
Step 1
Explain why chlorine (Cl₂) is a gas at room temperature
Answer
Chlorine (Cl₂) is a gas at room temperature due to the nature of its bonding. The chlorine molecules are held together by weak van der Waals forces, also known as London dispersion forces. These forces arise from temporary dipoles that occur due to the movement of electrons. Since the intermolecular forces are weak, chlorine molecules can move freely, allowing them to exist as a gas. Additionally, chlorine forms diatomic molecules (Cl₂) which are relatively small and have low boiling points, further supporting its gaseous state.
Step 2
Explain why sodium chloride (NaCl) is a solid at room temperature
Answer
Sodium chloride (NaCl) is a solid at room temperature due to the strong ionic bonds formed between sodium ions (Na⁺) and chloride ions (Cl⁻). These ionic bonds result from the electrostatic attraction between oppositely charged ions. In a solid state, sodium chloride forms a giant lattice structure where each ion is surrounded by ions of the opposite charge, creating a stable and strong framework. The large amounts of energy required to break these ionic bonds contribute to its high melting point, which is why sodium chloride remains solid at room temperature.
Step 3
Describe the bonding and structure of chlorine
Answer
Chlorine consists of diatomic molecules (Cl₂), which are held together by covalent bonds formed between two chlorine atoms. Each chlorine atom shares one electron with the other to achieve a stable electronic configuration, resembling that of the nearest noble gas. The structure of chlorine is simple and molecular, with the molecules existing independently and exhibiting low intermolecular forces.
Step 4
Describe the bonding and structure of sodium chloride
Answer
Sodium chloride has an ionic bonding structure, characterized by strong attractions between positively charged sodium ions (Na⁺) and negatively charged chloride ions (Cl⁻). These ions are arranged in a three-dimensional lattice, where each ion is surrounded by six oppositely charged ions, maximizing the electrostatic attractions. This structure is responsible for the high melting point and solidity of sodium chloride at room temperature.